WorldWideScience

Sample records for entanglement der zusammenhang

  1. Der Zusammenhang zwischen Elternarbeit und Hilfeverlauf [Relationship between cooperation with parents and success of the service

    OpenAIRE

    Schmidt-Neumeyer, Heike; Vossler, Andreas; Schmidt-Neumeyer, Willibald

    2002-01-01

    Der vorliegende Artikel beschreibt und interpretiert einige Ergebnisse einer Untersuchung in den Wohngruppen einer Jugendhilfeeinrichtung über den Zusammenhang von Elternarbeit und Hilfeverlauf. Auch werden Konsequenzen für die Praxis aufgezeigt, die sich aus der Interpretation der Untersuchungsergebnisse ergeben können.

  2. Zusammenhang zwischen Ölpreisentwicklung und der Aktienperformance börsennotierter Logistikdienstleister

    DEFF Research Database (Denmark)

    Hofmann, Erik; Prockl, Günter

    2017-01-01

    Auf Basis von einfachen Methoden werden zwei konträre Thesen untersucht zum möglichen Zusammenhang zwischen der Aktienkursperformance von Logistikdienstleistern und der Ölpreisentwicklung als ein wesentlicher Kostenfaktor – speziell für Transportdienstleistungen. Neben Gesamtauswertungen einer gl...

  3. Der Zusammenhang von Partnermarktopportunitäten aus dem Freundeskreis und der Stabilität von Paarbeziehungen : Eine Analyse mit den Daten des Partnermarktsurvey

    OpenAIRE

    Häring, Armando

    2014-01-01

    "Der Beitrag analysiert den Zusammenhang zwischen Partnermarktoportunitäten aus dem Freundeskreis und der Stabilität von Paarbeziehungen. Unter Verwendung des theoretischen Konzepts der Theorie der Interaktionsgelegenheiten sowie von Annahmen der Austauschtheorie und der Familienökonomie, werden mögliche Zusammenhänge zwischen gemeinsamen Freundeskreisen mit dem Partner, Partnermarktgelegenheiten aus dem Freundeskreis (sex ratio) und der Stabilität von Paarbeziehungen diskutiert. Der Beitrag ...

  4. Der Zusammenhang zwischen sportlicher Aktivität und visuell-räumlichen Fähigkeiten

    OpenAIRE

    Pietsch, Stefanie

    2012-01-01

    Thema dieser Arbeit ist es, den Zusammenhang zwischen motorischen bzw. sportlichen Fähigkeiten und visuell-räumlichen Fähigkeiten zu untersuchen. Speziell wird die Bedeutung der konditionellen und koordinativen Fähigkeiten für die mentale Rotationsleistungsfähigkeit, einer klassischen Aufgabe zur Erfassung des visuell-räumlichen Vorstellungsvermögens, untersucht. Die Beteiligung motorischer Prozesse an der mentalen Rotation sowie die Tatsache, dass die Fähigkeit mental zu rotieren durch kogn...

  5. Morphologische Qualitätsmerkmale der Mäuseeizelle und deren Zusammenhang mit einer Fehlverteilung des Chromosoms 16

    OpenAIRE

    Rogge, Sabine

    2009-01-01

    Eizellen der Maus wurden nach lichtmikroskopischen Kriterien bewertet. Mittels Fluoreszenz- in- situ- Hybridisierung wurden zudem meiotische Fehlverteilungen des Chromosom 16 der Maus 16 dargestellt. Die Korrelation zwischen morphologischen Kriterien und chromosomaler Fehlverteilung wurde untersucht.

  6. Verantwortliche Personalführung – Zufriedene Kunden. Der Zusammenhang von Gesundheitsmanagement, Gefährdungsbeurteilung und Kundenzufriedenheit an der SUB Hamburg

    Directory of Open Access Journals (Sweden)

    Ulrike Lang

    2015-12-01

    Full Text Available Das Arbeitsschutzgesetz verpflichtet Arbeitgeber, auf der Basis einer Beurteilung der Arbeitsbedingungen erforderliche Maßnahmen des Arbeitsschutzes festzustellen, diese umzusetzen und auf ihre Wirksamkeit zu kontrollieren. Dabei sind auch die psychischen Belastungen der Arbeit zu berücksichtigen. Wie werden diese Anforderungen im laufenden Betrieb umgesetzt? Welche Konsequenzen hat dies für Leitung, für Kolleg/inn/en und Nutzer/innen? Wie integriert man die Maßnahmen in die Personalentwicklung und wie überzeugt man die Beschäftigten davon, sich zu beteiligen? Der Beitrag erläutert die Entwicklung des Gesundheitsmanagements der Staats- und Universitätsbibliothek Hamburg Carl von Ossietzky und bietet Tipps zur Umsetzung in anderen Bibliotheken. The German Occupational Safety and Health Act requires employers to determine, based on an assessment of the working conditions, which occupational safety and health measures are required, to implement them and to monitor their effectiveness. The mental stress of work has to be considered as well. How are these requirements implemented under operating conditions? What are the implications for management, colleagues and for the users? How should the measures be integrated in human resources development and how can the employees be persuaded to participate? The paper explains the development of the health management at the State and University Library Hamburg Carl von Ossietzky and gives advice on the implementation to other libraries.

  7. Interdependences between flow patterns and oxygen entry in aeration tanks of wastewater treatment plants; Der Zusammenhang von Stroemungsstrukturen und Sauerstoffeintrag bei druckbeluefteten Belebungsbecken

    Energy Technology Data Exchange (ETDEWEB)

    Thiersch, B.

    2001-07-01

    The flow field, turbulence intensities and the distribution of the relative gas-holdup of aeration tanks of operating wastewater treatment plants were investigated experimentally with Acoustic-Doppler-Velocimeter probes. Based on the experimental results a hydrodynamical model in Euler-Euler-Formulation was developed and numerical studies of different tank and diffuser arrangements were performed. It was found that the flow pattern is mainly influenced by the gas sparger arrangement and the tank aspect-ratio. Combining the experimental and numerical results reasons for different aeration efficiencies were identified. Increasing the diffuser density changed the flow field from the spiral type to the cellular pattern with instable and dynamical structures. These flow patterns improved the aeration efficiency by increasing the residence time of the bubbles and the recirculating flows. (orig.) [German] In der vorliegenden Arbeit werden grundlegende Stroemungsstrukturen von druckbeluefteten Belebungsbecken anhand messtechnischer Untersuchungen der Geschwindigkeitsverteilungen, Turbulenzgroessen und relativer Gasgehaltsverteilungen von Belebungsbecken im Betriebszustand aufgezeigt. Vorab wird die Einsatzfaehigkeit von Akkustik-Doppler-Sonden in dispersen Zweiphasenstroemungen detailliert ueberprueft. Aufbauend auf den Messergebnissen wird ein numerisches Simulationsprogramm zur dynamischen Berechnung unterschiedlicher Beckenkonfigurationen entwickelt. Aus den experimentellen Ergebnissen in Verbindung mit den Berechnungsergebnissen sowie den Auswertungen frueherer Untersuchungen konnten hydromechanische Ursachen der unterschiedlichen Sauerstoffeintragseffizienz bei verschiedenen Beckenkonzeptionen abgeleitet werden. Dabei stellen die Anordnung sowie Gleichverteilung der Belueftungselemente sowie das Querschnittsverhaeltnis der Belebungsbecken die wesentlichen Einflussgroessen auf die Ausbildung der Stroemungsstrukturen dar. Mit zunehmender Belegungsdichte und

  8. Wie schreiben sprachschwache Kinder? Beitrag zum Zusammenhang zwischen explizitem und implizitem Sprachwissen

    OpenAIRE

    Schaller, Pascale

    2017-01-01

    Der Beitrag fokussiert den Zusammenhang zwischen sprachlich explizitem und implizitem Wissen in den Bereichen Wortschatz, Grammatik und Orthographie bei sprachschwachen Kindern. Er plädiert dafür, Schreiben als Sprachhandlung aufzufassen und neben dem Textprodukt den Schreibprozess und die Sprachwissensvoraussetzungen der Kinder als diagnostisch relevante Aspekte zu reflektieren. Anhand empirischer Analysen aus einer explorativen Studie wird aufgezeigt, dass sich das Verhältnis von explizitem...

  9. Initiatives for sustainable development: New forms of dialogue and styles of communication in connection with the implementation of the Agenda 21. Final report; Initiativen fuer eine nachhaltige Entwicklung: Neue Dialogformen und Kommunikationsstile im Zusammenhang mit der Umsetzung der Agenda 21. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Haan, G. de; Kuckartz, U.; Rheingans, A. [comps.

    1998-11-01

    The study deals with questions of participation and the communication on environmental issues within the framework of the implementation of the Agenda 21. Employing social-science field research tools, Local Agenda 21 initiatives in selected areas of the capital, Berlin, were accompanied for a period of 15 months.- The data material consists for one thing of field notes and for another of records of interviews conducted with players in these initiatives and experts in their environment (politics, administration, economy, associations). The interviews asked open questions and followed a given layout. The data were subjected to computer-based qualitative analysis. The main objective was to identify the paradigms relevant in the Agenda process.- Some results of the analysis are organization models of LA 21 initiatives and a typology of paradigms of players. A survey among citizens carried out following the field study informs on the participation interests of the public, its familiarity with the Local Agenda initiatives, and the dissemination of knowledge on the concept of sustainable development. (orig.) [Deutsch] Die Studie befasst sich mit Fragen der Partizipation und der Umweltkommunikation im Zuge der Umsetzung der Agenda 21. Mit den Mitteln sozialwissenschaftlicher Feldforschung wurden Lokale Agenda 21-Initiativen in ausgewaehlten Bezirken der Hauptstadt Berlin ueber einen Zeitraum von 15 Monaten begleitet. Das Datenmaterial besteht neben Feldnotizen und Protokollen aus offenen, leitfadenstrukurierten Interviews, die mit Akteuren der Initiativen und mit Experten ihres Umfeldes (Politik, Verwaltung, Wirtschaft, Verbaende) gefuehrt wurden. Die Daten wurden mittels computergestuetzter qualitativer Inhaltsanalyse ausgewertet. Dabei ging es vorrangig um die Identifizierung der im Agenda-Prozess virulenten Leitbilder. Resultate der Analyse sind u.a. Modelle der Organisation von LA 21-Initiativen sowie eine Typologie von Akteursleitbildern. Eine im Anschluss an die

  10. Entanglement verification and its applications in quantum communication; Verschraenkungsnachweise mit Anwendungen in der Quantenkommunikation

    Energy Technology Data Exchange (ETDEWEB)

    Haeseler, Hauke

    2010-02-16

    In this thesis, we investigate the uses of entanglement and its verification in quantum communication. The main object here is to develop a verification procedure which is adaptable to a wide range of applications, and whose implementation has low requirements on experimental resources. We present such a procedure in the form of the Expectation Value Matrix. The structure of this thesis is as follows: Chapters 1 and 2 give a short introduction and background information on quantum theory and the quantum states of light. In particular, we discuss the basic postulates of quantum mechanics, quantum state discrimination, the description of quantum light and the homodyne detector. Chapter 3 gives a brief introduction to quantum information and in particular to entanglement, and we discuss the basics of quantum key distribution and teleportation. The general framework of the Expectation Value Matrix is introduced. The main matter of this thesis is contained in the subsequent three chapters, which describe different quantum communication protocols and the corresponding adaptation of the entanglement verification method. The subject of Chapter 4 is quantum key distribution, where the detection of entanglement is a means of excluding intercept-resend attacks, and the presence of quantum correlations in the raw data is a necessary precondition for the generation of secret key. We investigate a continuous-variable version of the two-state protocol and develop the Expectation Value Matrix method for such qubit-mode systems. Furthermore, we analyse the role of the phase reference with respect to the security of the protocol and raise awareness of a corresponding security threat. For this, we adapt the verification method to different settings of Stokes operator measurements. In Chapter 5, we investigate quantum memory channels and propose a fundamental benchmark for these based on the verification of entanglement. After describing some physical effects which can be used for the

  11. Review Essay: Spiegelneuronen in der sozialwissenschaftlichen Diskussion

    OpenAIRE

    Pätzold, Henning

    2010-01-01

    Seit ihrer Entdeckung Mitte der 1990er Jahre sind Spiegelneuronen kontinuierlicher Gegenstand neuro- wie sozialwissenschaftlicher Debatten. Das besondere Interesse von Wissenschaftler/innen außerhalb der biologischen Disziplinen beruht auch darauf, dass Spiegelneuronen nicht nur allgemeine erkenntnistheoretische Bedeutung haben, sondern auch im Zusammenhang mit fundamentalen sozialen Erkenntnis- und Empfindungsformen wie Empathie eine wichtige Rolle zu spielen scheinen. Mit dem Buch von Nadia...

  12. Externe Effekte der Laufwasserkraftnutzung

    OpenAIRE

    Kohler, Beate

    2006-01-01

    In den vergangenen Jahrzehnten hat eine zunehmende Sensibilisierung bzgl. der Vermeidung von Umweltbelastungen im Zusammenhang mit dem Abbau und dem Verbrauch natürlicher Ressourcen stattgefunden. Das Thema ist nicht nur Gegenstand von Wissenschaft und Politik, sondern wird von einer breiten Öffentlichkeit diskutiert. Da Energieerzeugung stets an die Nutzung und insofern auch an die Belastung natürlicher Ressourcen gebunden ist, betrifft diese Thematik Energieversorgungsunternehmen in besonde...

  13. Subventionierung von erneuerbarer Energie : eine industrieökonomische Analyse des strategischen Wettbewerbs in der Erneuerbaren-Energieindustrie bei unterschiedlichen staatlichen Regulierungen

    OpenAIRE

    Schaller, Markus

    2006-01-01

    In der vorliegenden Arbeit werden ausgewählte Probleme, die im Zusammenhang mit der Subventionierung von erneuerbarer Energien stehen, in finanztheoretischen und industrieökonomischen Modellen formal analysiert. Der erste Teil der Arbeit beschäftigt sich mit der Subventionierung von Demonstrationsprojekten zur Erprobung neuer Technologien der erneuerbaren Energiegewinnung. Die Information, die durch die Erprobung über die wirtschaftliche Leistungsfähigkeit der Technologie generiert wird, ist...

  14. Kanban - der Weg ist das Ziel

    Science.gov (United States)

    Aull, Florian; Berlak, Joachim; Dickmann, Eva; Dickmann, Philipp; Fischäder, Holm; Gerlach, Joachim; Henneberg, Jens; Kapalla, Klaus; Kress, Oliver; Kuttler, Robert; Schneider, Herfried M.; Schürle, Philipp; Stellpflug, Franz-Josef; Wannenwetsch, Ralph; Wulz, Johannes; Zäh, Michael F.

    Wenn man aktuell Produktionsbereiche in Deutschland und Europa besucht, fallen im Zusammenhang mit modernen Produktionsmethoden immer öfter die Begriffe Kanban (jap. Karte, Signal) und Pull-Produktion, und dies nicht ohne Stolz, da diese mit dem schillernden Vorbild des Toyota Produktionssystems in Zusammenhang stehen. Tatsächlich ist Kanban ein integraler Bestandteil moderner Produktionssysteme. Blickt man aber im Rahmen von Prozessanalysen hinter die Fassaden", d. h. in die tägliche Praxis der Arbeitsprozesse, wird man schnell desillusioniert - die viel gepriesenen klassischen Kanban-Regeln werden im Tagesgeschäft nicht eingehalten.

  15. The future of thermal waste treatment; Zukunft der thermischen Restabfallbehandlung

    Energy Technology Data Exchange (ETDEWEB)

    Wiemer, K.; Kern, M. (eds.); Tappen, I.; Weber-Wied, R. (comps.)

    2001-07-01

    Contents: State of the art of energy-efficient thermal waste treatment processes and practical examples; Regional and economic aspects; Licensing problems of thermal waste treatment plants. [German] Der vorliegende Tagungsband zum 2. Stassfurter Abfall- und Energieforum beschreibt den aktuellen Stand energieeffizienter thermischer Abfallbehandlungsmethoden an praktischen Beispielen und stellt den Bezug dieser Massnahmen zum raeumlich-wirtschaftlichen Umfeld dar. Darueber hinaus werden vergaberechtliche Fragen im Zusammenhang mit der europaweiten Ausschreibungspflicht fuer die Errichtung thermischer Abfallbehandlungsanlagen aufgezeigt und eroertert. (orig.)

  16. Medienbildung in der Volksschule

    Directory of Open Access Journals (Sweden)

    Katharina Grubesic

    2013-12-01

    Full Text Available In dieser Untersuchung steht der Zusammenhang zwischen Schule und Medien in Bezug auf die Wertvorstellungen und Einstellungen der Akteure auf Grundlage des Habituskonzepts von Bourdieu sowie des Konzepts des medialen Habitus von Kommer und Biermann im Mittelpunkt. Die von den Lehrenden vorgelebten verinnerlichten Dispositionen im handlungsspezifischen Umgang mit unterschiedlichen Medien als auch der zu Grunde liegende „legitime Geschmack“, in dem sich diese Veranlagungen ausdrücken, sind hierbei bedeutsam. Die Rekonstruktion des medialen Habitus von LehrerInnen wird durch einen Vergleich zweier divergierender Unterrichtskonzeptionen mit der Methode der Videoanalyse erreicht. Das mediendidaktische Design, die Mediennutzung und die aktive Unterrichtsbeteiligung stellen die Analyseschwerpunkte dar, die der Beschreibung der verinnerlichten Dispositionen aufgrund der vorgelebten Haltungen und Wertvorstellungen dienen. Die anschließende relationierte Beobachtung ermöglicht es, in Anlehnung an die Habitustypen von Mutsch, die Differenzen und Gemeinsamkeiten der Unterrichtskonzepte sowie der daraus resultierenden Chancen und Schwierigkeiten im Unterricht zu verdeutlichen. This study attempts to show the correlation between school and media based on media habits, experiences and patterns of media usage of teachers and pupils in primary schools. As a theoretical framework, Bourdieu’s conception of habitus and the conception of media habitus of Kommer and Biermann are used to reconstruct the media habitus of primary school teachers in different educational settings. In this research, media habitus is understood as a combination of media economic capital, media activities, experience and preferences, values and attitudes of media in daily routine just as purposes and motives of media usage and educational intervention in family life. This work focuses on pointing out the relevance of teachers’ media habitus in different educational designs in

  17. Generalizing entanglement

    Science.gov (United States)

    Jia, Ding

    2017-12-01

    The expected indefinite causal structure in quantum gravity poses a challenge to the notion of entanglement: If two parties are in an indefinite causal relation of being causally connected and not, can they still be entangled? If so, how does one measure the amount of entanglement? We propose to generalize the notions of entanglement and entanglement measure to address these questions. Importantly, the generalization opens the path to study quantum entanglement of states, channels, networks, and processes with definite or indefinite causal structure in a unified fashion, e.g., we show that the entanglement distillation capacity of a state, the quantum communication capacity of a channel, and the entanglement generation capacity of a network or a process are different manifestations of one and the same entanglement measure.

  18. Entanglement detection

    Energy Technology Data Exchange (ETDEWEB)

    Guehne, Otfried [Institut fuer Quantenoptik und Quanteninformation, Osterreichische Akademie der Wissenschaften, Technikerstrasse 21A, A-6020 Innsbruck (Austria); Institut fuer theoretische Physik, Universitaet Innsbruck, Technikerstrasse 25, A-6020 Innsbruck (Austria)], E-mail: otfried.guehne@uibk.ac.at; Toth, Geza [Department of Theoretical Physics, University of the Basque Country, P.O. Box 644, E-48080 Bilbao (Spain); Ikerbasque-Basque Foundation for Science, Alameda Urquijo 36, E-48011 Bilbao (Spain); ICFO-Institute of Photonic Sciences, Mediterranean Technology Park, E-08860 Castelldefels (Barcelona) (Spain); Research Institute for Solid State Physics and Optics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary)

    2009-04-15

    How can one prove that a given quantum state is entangled? In this paper we review different methods that have been proposed for entanglement detection. We first explain the basic elements of entanglement theory for two or more particles and then entanglement verification procedures such as Bell inequalities, entanglement witnesses, the determination of nonlinear properties of a quantum state via measurements on several copies, and spin squeezing inequalities. An emphasis is given to the theory and application of entanglement witnesses. We also discuss several experiments, where some of the presented methods have been implemented.

  19. Zur methodik der ninhydrinreaktion und papierchromatographie im zusammenhang mit untersuchungen uber gerinnungsphysiologisch interessierende phosphatide

    NARCIS (Netherlands)

    Hecht, E.; Mink, C.

    1952-01-01

    In view of other researches, the authors have studied the ninhydrin reaktion in order to obtain evidence of free amino-N of phosphatides and their fission products. Apart from the study of paper chromatography of nitrogenated lipoids, the details of general interest are given of the technique

  20. Typologische Aufgaben der historischen Textlinguistik

    Directory of Open Access Journals (Sweden)

    Ingo Warnke

    1995-12-01

    Full Text Available Die gegenwärtige germanistische Historiolinguistik ist geprägt durch eine pragmatische Ausweitung ihres traditionell sprachstrukturellen Erkenntnisinteresses. Ausdruck dieser Entwicklung ist z.B. die gänzliche Neubearbeitung der Sprachgeschichte von P. von Polenz (1991 und 1994, die an Stelle der wiederholt neu aufgelegten und auf H. Sperber (1926 gründenden Geschichte der deutschen Sprache (von Polenz 1978 erschienen ist und insbesondere eine "sozial- und mediengeschichtliche Fundierung" (ebd., 3 anstrebt, wobei neben anderen Aspekten als Schwerpunkt der Darstellung explizi1t die Sprachpragmatik genannt wird (ebd.. Sind die konzeptionellen Ecksteine einer solchen pragmatischen Sprachgeschichtsschreibung auch schon Anfang der 1980er Jahre insbesondere mit H. Sitta (1980 und D. Cherubim (1984 gesetzt, so verstärkt sich das sprachhandlungsbezogene Interesse an der Geschichte des Deutschen erst in jüngster Zeit. Die Entwicklung läuft dabei parallel zur Konstituierung eines pragmatischen Paradigmas, das als Gemeinschaftswerk geisteswissenschaftlicher Forschung ebenfalls in den 1980er Jahren an Bedeutung gewann und als dessen notwendige Folge H. Stachowiak ([Hg.] 1986, XVII einen '"Paradigmawechsel' großen Stils" prophezeit hat.1 Bei den Pragmatisierungstendenzen sprachgeschichtlicher Fragestellungen kommt der historischen Dimensionierung textlinguistischer Erkenntnisfelder besondere Bedeutung zu. Es ist bekannt, daß die in den späten 1960er und 70er Jahren begründete Textlinguistik zunächst ebenso ahistorisch gewesen ist, wie die Historiolinguistik apragmatisch. Doch mit der fortschreitenden Rezeption sprachhandlungsorientierter Ansätze in der Sprachgeschichte gewann der Text i.S. einer komplexen sprachlichen Handlung (vgl. u.a. Sandig 1978, 69f., 99ff., 157f. als Analyseobjekt für die pragmatische Orientierung der Sprachgeschichte zunehmend an Bedeutung. In diesem Zusammenhang ist die Forderung nach textlinguistischer bzw

  1. Modular entanglement.

    Science.gov (United States)

    Gualdi, Giulia; Giampaolo, Salvatore M; Illuminati, Fabrizio

    2011-02-04

    We introduce and discuss the concept of modular entanglement. This is the entanglement that is established between the end points of modular systems composed by sets of interacting moduli of arbitrarily fixed size. We show that end-to-end modular entanglement scales in the thermodynamic limit and rapidly saturates with the number of constituent moduli. We clarify the mechanisms underlying the onset of entanglement between distant and noninteracting quantum systems and its optimization for applications to quantum repeaters and entanglement distribution and sharing.

  2. Evaluation der Kurse 'Deutsch als Fremdsprache' im Akademischen Auslandsamt Siegen : ein Beitrag zur Qualitätssicherung und -entwicklung

    OpenAIRE

    Moll, Katharina

    2011-01-01

    Der Begriff "Qualität" im Kontext von Lehre und Unterricht ist schon seit Jahren in aller Munde. Nicht erst, aber insbesondere seit der Veröffentlichung der ersten PISA-Studie fordern Politiker umfassende Managementsysteme zur Verbesserung der Qualität von Bildungseinrichtungen in Deutschland. In diesem Zusammenhang wurden in den letzten Jahren viele Ideen entwickelt, die helfen sollen, die Qualität der Bildung zu verbessern. Vor allem für den schulischen Bereich, der besonders unter Druck ge...

  3. Entangled entanglement: A construction procedure

    Energy Technology Data Exchange (ETDEWEB)

    Uchida, Gabriele, E-mail: Gabriele.Uchida@univie.ac.at [University of Vienna, Faculty of Computer Science, Währinger Strasse 29, 1090 Vienna (Austria); Bertlmann, Reinhold A., E-mail: Reinhold.Bertlmann@univie.ac.at [University of Vienna, Faculty of Physics, Boltzmanngasse 5, 1090 Vienna (Austria); Hiesmayr, Beatrix C., E-mail: Beatrix.Hiesmayr@univie.ac.at [University of Vienna, Faculty of Physics, Boltzmanngasse 5, 1090 Vienna (Austria)

    2015-10-30

    The familiar Greenberger–Horne–Zeilinger (GHZ) states can be rewritten by entangling the Bell states for two qubits with a third qubit state, which is dubbed entangled entanglement. We show that in a constructive way we obtain all eight independent GHZ states that form the simplex of entangled entanglement, the magic simplex. The construction procedure allows a generalization to higher dimensions both, in the degrees of freedom (considering qudits) as well as in the number of particles (considering n-partite states). Such bases of GHZ-type states exhibit a cyclic geometry, a Merry Go Round, that is relevant for experimental and quantum information theoretic applications.

  4. Eine Analyse des Zusammenhangs zwischen dem Konsum von Alkopops und dem Problemverhalten von Jugendlichen

    OpenAIRE

    Metzner, Cornelia Beate Isabel

    2007-01-01

    Zielsetzung: In dieser Arbeit wird untersucht, ob bei Jugendlichen ein Zusammenhang zwischen dem Konsum von Alkopops einerseits und dem sonstigen Alkoholtrinkverhalten, dem Konsum von Zigaretten und illegalen Drogen sowie weiteren Risikoverhaltensweisen andererseits besteht, ferner ob sich Unterschiede im Verhalten von Jungen und Mädchen ergeben. Theoretischer und empirischer Hintergrund: �Alkopops�, d. h. Mischgetränke diverser Hersteller aus Likör bzw. Schnaps und Limonade sowie wein- ...

  5. New facade concepts ranging from statics to dynamics; Neue Fassadenkonzepte. Von der Statik zur Dynamik

    Energy Technology Data Exchange (ETDEWEB)

    Kranz, H.R. [Siemens AG, Karlsruhe (Germany)

    1995-12-31

    In chapter 9 of the anthology about building control new facade concepts are presented, including new facade technologies, conductivity of new facade concepts and combination of new technologies. The whole complex ranging from statics to dynamics is explained. (BWI) [Deutsch] Kapitel 9 des Sammelbandes ueber Building Control stellt neue Fassadenkonzepte vor: Neue Fassadentechnologien, Leitfunktionen neuer Fassadenkonzepte, Kombination neuer Technologien. In diesem Zusammenhang wird der gesamte Komplex von der Statik bis zur Dynamik behandelt. (BWI)

  6. 'Subjektives' und 'objektives' Wissen in der audiologischen Diagnose

    DEFF Research Database (Denmark)

    Egbert, Maria

    sozial-psychologischen Barrieren (z.B. Stigma) die Interaktion zwischen Audiologen und Patienten selten erfolgreich verläuft. Ein Hauptproblem liegt darin, die 'objektive' Hördiagnose, (erstellt durch ein Audiogramm) in Zusammenhang zu bringen mit den 'subjektiven' Hörbeschreibungen des Patienten. Da der...... Audiologe sowohl auf die objektive als auch auf die subjektive Darstellung angewiesen ist, widmet sich diese Studie anhand von authentischen Videoaufnahmen diesen Diskrepanzen. Als methodischer Rahmen für die Anwendung der Ergebnisse werden die Ansätze "User-Centred Design" und "Social Innovation...

  7. The entanglement evolution between two entangled atoms

    Indian Academy of Sciences (India)

    ... entanglement between the two atoms changes periodically and undergoes the entanglement sudden death (ESD) and sudden birth at some time. The entanglement properties between the field and the atom insidethe cavity are dependent on the photon number. Most interestingly, the entanglement between the field and ...

  8. Biomass utilisation seen against the background of AGENDA 21; Biomassenutzung vor dem Hintergrund der AGENDA 21

    Energy Technology Data Exchange (ETDEWEB)

    Schoenwiesner-Bozkurt, C. [efreso AG, Muenchen (Germany)

    2000-07-01

    From 3 to 14 June 1992 Rio de Janeiro was host to the largest conference that had ever taken place up to that point in human history, the United Nations Conference on Environment and Development (UNCED). One major programmatic outcome of the conference was the approval of Agenda 21. This document was signed by 179 states, but it is not binding under international law. Altogether AGENDA 21 comprises 40 chapters. The present paper draws on a selection of these chapters to exemplify the significance of energy production from biomass and its relationship with the goals of Agenda 21. The author has refrained from discussing the issue of climate and energy policy in a wider context, as this matter will undoubtedly already be known to the reader. [German] Zwischen dem 03. und 14. Juni 1992 fand in Rio die bis dahin groesste Konferenz der Menschheitsgeschichte statt. Die Konferenz der Vereinten Nationen ueber Umwelt und Entwicklung 'United Nations Conference on Environment and Development (UNCED)'. Als greifbares programmatisches Ergebnis der Konferenz wurde am Ende die Agenda 21 verabschiedet. Sie wurde von 179 Staaten unterzeichnet, ist aber voelkerrechtlich nicht verbindlich. Insgesamt umfasst die Agenda 21 40 Einzelkapitel. Beispielhaft soll anhand einiger Kapitel die Bedeutung und der Zusammenhang zwischen der energetischen Nutzung der Biomasse und den Zielen der Agenda 21 aufgezeigt werden. Bewusst wird hierbei der Themenbereich 'Klima- und Energiepolitik' nicht weiter betrachtet, da dieser Zusammenhang den Teilnehmern sicherlich bekannt ist. (orig.)

  9. Studying entanglement-assisted entanglement transformation

    International Nuclear Information System (INIS)

    Hsu Liyi

    2004-01-01

    In this paper, we study catalysis of entanglement transformations for n-level pure entangled states. We propose an algorithm of finding the required catalystic entanglement. We introduce several examples by way of demonstration. We evaluate the lower and upper bound of the required inequalities for deciding whether there are m-level appropriate catalyst states for entanglement transformations for two n-level pure entangled states

  10. Das Alter ist der wichtigste Risikofaktor der postoperativen erektilen Dysfunktion nach radikaler nerverhaltender Prostatektomie

    Directory of Open Access Journals (Sweden)

    Gruschka M

    2009-01-01

    Full Text Available Die radikale Prostatektomie ohne Nerverhalt geht mit Impotenz einher. Bei nerverhaltendem Vorgehen kann das Risiko der erektilen Dysfunktion gesenkt, aber nicht ausgeschlossen werden. Die präoperative Beratung der Patienten erfordert bei nerverhaltender Prostatektomie die Kenntnis der Faktoren, die Einfluss auf die postoperative Potenz haben. Patienten & Methoden: 110 Patienten antworteten 24 Monate nach radikaler perinealer nerverhaltender Prostatektomie auf einen per Post übermittelten Fragebogen. Die Patienten wurden, entsprechend dem Erection Hardness Score, nach der Rigidität ihrer Erektionen befragt. Überwiegend erfolgte der Nerverhalt unilateral (104/110. Verschiedene potenzielle Risikofaktoren (Alter, Qualität der präoperativen Erektion, Serum-PSA, Gleason-Score, Tumorvolumen, Prostatavolumen, adjuvante Strahlentherapie, ASA-Score, Chronic Disease Score [CDS], arterielle Hypertonie, Hypercholesterinämie, Diabetes mellitus, KHK, Nikotinkonsum wurden univariat mit der postoperativ erzielten Potenz korreliert. Multivariat wurden dann jene Parameter untersucht, die in der univariaten Analyse einen signifikanten (p ≤ 0,05 oder einen tendenziellen Zusammenhang (p ≤ 0,2 mit der postoperativen erektilen Funktion aufwiesen. Ergebnisse:Das Alter (p 0,001 und der ASAScore (p = 0,018 waren in der univariaten Analyse negative Prädiktoren der postoperativen Potenz. In der multivariaten Analyse war lediglich das Alter (p = 0,028 von signifikanter Bedeutung. Mit jedem Lebensjahr der Männer steigt das Risiko einer um eine Stufe im EHS schlechteren Erektion um das 1,128-Fache an. Bei einem Altersunterschied von 10 Jahren ist das Risiko eines postoperativ schlechteren Erektionsvermögens um den Faktor 3,334 erhöht, bei einem um 20 Jahre höheren Alter beträgt dieser Faktor 11,121. Diskussion & Praxisrelevanz: Das Lebensalter der Patienten wurde im Einklang mit der Literatur als signifikanter Faktor für die postoperative Potenz identifiziert

  11. Beitrag zur Beziehung von Video-Filmkonsum und Kriminalität in der Adoleszenz

    OpenAIRE

    Klosinski, G.

    1987-01-01

    Anhand von 3 Kasuistiken jugendlicher und heranwachsender Straftäter, die im Rahmen einer forensischen Begutachtung jugendpsychiatrisch untersucht wurden, wird aufgezeigt, wie im Einzelfall die Art und Weise der Ausführung des betreffenden Deliktes, die Tatmotivation und die nachträgliche "Rechtfertigung" mit großer Wahrscheinlichkeit in einem direkten Zusammenhang mit vorher gesehenen Horror- und Porno-Videos standen. Eine jeweils auffällige Persönlichkeitsproblematik erfuhr durch ein "Vor-B...

  12. The entanglement evolution between two entangled atoms

    Indian Academy of Sciences (India)

    Entanglement is an important resource for quantum information processing. [1–3] and also one of the most important nonclassical properties in quantum theory. ... consideration, which consists of two entangled two-level atoms A and B with ...

  13. Charcterization of multipartite entanglement

    International Nuclear Information System (INIS)

    Chong, Bo

    2006-01-01

    In this thesis, we discuss several aspects of the characterization of entanglement in multipartite quantum systems, including detection, classification and quantification of entanglement. First, we discuss triqubit pure entanglement and propose a special true tripartite entanglement, the mixed entanglement, besides the Greenberger-Horne-Zeilinger (GHZ) entanglement and the W entanglement. Then, based on quantitative complementarity relations, we draw entanglement Venn diagrams for triqubit pure states with different entanglements and introduce the total tangle τ (T) to quantify total entanglement of triqubit pure states by defining the union I that is equivalent to the total tangle τ (T) from the mathematical point of view. The generalizations of entanglement Venn diagrams and the union I to N-qubit pure states are also discussed. Finally, based on the ranks of reduced density matrices, we discuss the separability of multiparticle arbitrary-dimensional pure and mixed states, respectively. (orig.)

  14. Charcterization of multipartite entanglement

    Energy Technology Data Exchange (ETDEWEB)

    Chong, Bo

    2006-06-23

    In this thesis, we discuss several aspects of the characterization of entanglement in multipartite quantum systems, including detection, classification and quantification of entanglement. First, we discuss triqubit pure entanglement and propose a special true tripartite entanglement, the mixed entanglement, besides the Greenberger-Horne-Zeilinger (GHZ) entanglement and the W entanglement. Then, based on quantitative complementarity relations, we draw entanglement Venn diagrams for triqubit pure states with different entanglements and introduce the total tangle {tau}{sup (T)} to quantify total entanglement of triqubit pure states by defining the union I that is equivalent to the total tangle {tau}{sup (T)} from the mathematical point of view. The generalizations of entanglement Venn diagrams and the union I to N-qubit pure states are also discussed. Finally, based on the ranks of reduced density matrices, we discuss the separability of multiparticle arbitrary-dimensional pure and mixed states, respectively. (orig.)

  15. Rezension von: Ulrike Klöppel: XX0XY ungelöst. Hermaphroditismus, Sex und Gender in der deutschen Medizin. Eine historische Studie zur Intersexualität. Bielefeld: transcript Verlag 2010.

    Directory of Open Access Journals (Sweden)

    Sarah Radtke

    2010-10-01

    Full Text Available Ulrike Klöppel führt in ihrer materialreichen Studie vor, dass Hermaphroditismus für die Medizin immer wieder Anlass war, sich mit der Vielfalt der das Geschlecht bestimmenden Faktoren – Gestalt und Form der Genitalien, Chromosomengeschlecht, Keimdrüsengeschlecht (Hoden vs. Eierstöcke, Hormonhaushalt, Geschlechtsrolle und Geschlechtsidentität – zu befassen und zu versuchen, Geschlechtszugehörigkeiten verbindlich festzulegen. Neben einem historischen Teil, der vor allem die Medizingeschichte der Frühen Neuzeit, der Aufklärungszeit und des 19. Jahrhunderts in den Blick nimmt, wird im zweiten Teil der Arbeit der Zusammenhang zwischen der Formierung des gender-Konzepts und dem damit verbundenen Paradigmenwechsel in der Behandlung von Intersexualität dargestellt.

  16. Typical entanglement

    Science.gov (United States)

    Deelan Cunden, Fabio; Facchi, Paolo; Florio, Giuseppe; Pascazio, Saverio

    2013-05-01

    Let a pure state | ψ> be chosen randomly in an NM-dimensional Hilbert space, and consider the reduced density matrix ρ A of an N-dimensional subsystem. The bipartite entanglement properties of | ψ> are encoded in the spectrum of ρ A . By means of a saddle point method and using a "Coulomb gas" model for the eigenvalues, we obtain the typical spectrum of reduced density matrices. We consider the cases of an unbiased ensemble of pure states and of a fixed value of the purity. We finally obtain the eigenvalue distribution by using a statistical mechanics approach based on the introduction of a partition function.

  17. Nationalsozialismus und Holocaust in der spanischen Gegenwartsliteratur: Fiktionalisierte ‚images malgré tout‘ bei Ricardo Menéndez Salmón

    Directory of Open Access Journals (Sweden)

    Marco Thomas Bosshard

    2015-12-01

    Full Text Available Der vorliegende Artikel untersucht die literarischen Repräsentationen von nationalsozialistischen Kriegsverbrechen in den Romanen La ofensa und Medusa des spanischen Schriftstellers Ricardo Menéndez Salmón. Ausgehend von einer Kontextualisierung der Romane im Gesamtschaffen des Autors werden intertextuelle Bezüge nicht nur zu anderen literarischen Texten, sondern auch zur Theorie herausgearbeitet. Gegenüber dem im Zusammenhang mit Holocaust-Darstellungen oft postulierten ‚Bilderverbot‘ realisiert Menéndez Salmón in Anlehnung an Didi-Huberman fiktionalisierte images malgré tout im Medium der Sprache, deren Funktion über die Darstellung von Nazi-Verbrechen hinausgeht und eine metamediale Reflexion über den Zusammenhang von Bild, Sprache und Schrecken anstößt.

  18. Brownian entanglement

    International Nuclear Information System (INIS)

    Allahverdyan, A.E.; Khrennikov, A.; Nieuwenhuizen, Th.M.

    2005-01-01

    For two classical Brownian particles an analog of continuous-variable quantum entanglement is presented: The common probability distribution of the two coordinates and the corresponding coarse-grained velocities cannot always be prepared via mixing of any factorized distributions referring to the two particles separately. This is possible for particles which have interacted in the past, but do not interact at present. Three factors are crucial for the effect: (1) separation of time scales of coordinate and momentum which motivates the definition of coarse-grained velocities; (2) the resulting uncertainty relations between the coordinate of the Brownian particle and the change of its coarse-grained velocity; (3) the fact that the coarse-grained velocity, though pertaining to a single Brownian particle, is defined on a common context of two particles. The Brownian entanglement is a consequence of a coarse-grained description and disappears for a finer resolution of the Brownian motion. Analogies with the quantum situation are discussed, as well as possibilities of experimental realization of the effect in examples of macroscopic Brownian motion

  19. Quantum entanglement

    International Nuclear Information System (INIS)

    Hadjiivanov, L.; Todorov, I.

    2015-01-01

    Expository paper providing a historical survey of the gradual transformation of the 'philosophical discussions' between Bohr, Einstein and Schrödinger on foundational issues in quantum mechanics into a quantitative prediction of a new quantum effect, its experimental verification and its proposed (and loudly advertised) applications. The basic idea of the 1935 paper of Einstein-Podolsky-Rosen (EPR) was reformulated by David Bohm for a finite dimensional spin system. This allowed John Bell to derive his inequalities that separate the prediction of quantum entanglement from its possible classical interpretation. We reproduce here their later (1971) version, reviewing on the way the generalization (and mathematical derivation) of Heisenberg's uncertainty relations (due to Weyl and Schrödinger) needed for the passage from EPR to Bell. We also provide an improved derivation of the quantum theoretic violation of Bell's inequalities. Soon after the experimental confirmation of the quantum entanglement (culminating with the work of Alain Aspect) it was Feynman who made public the idea of a quantum computer based on the observed effect

  20. Remote entanglement distribution

    International Nuclear Information System (INIS)

    Sanders, B.C.; Gour, G.; Meyer, D.A.

    2005-01-01

    Full text: Shared bipartite entanglement is a crucial shared resource for many quantum information tasks such as teleportation, entanglement swapping, and remote state preparation. In general different nodes of a quantum network share an entanglement resource, such as ebits, that are consumed during the task. In practice, generating entangled states is expensive, but here we establish a protocol by which a quantum network requires only a single supplier of entanglement to all nodes who, by judicious measurements and classical communication, provides the nodes with a unique pair wise entangled state independent of the measurement outcome. Furthermore, we extend this result to a chain of suppliers and nodes, which enables an operational interpretation of concurrence. In the special case that the supplier shares bipartite states with two nodes, and such states are pure and maximally entangled, our protocol corresponds to entanglement swapping. However, in the practical case that initial shared entanglement between suppliers and nodes involves partially entangled or mixed states, we show that general local operations and classical communication by all parties (suppliers and nodes) yields distributions of entangled states between nodes. In general a distribution of bipartite entangled states between any two nodes will include states that do not have the same entanglement; thus we name this general process remote entanglement distribution. In our terminology entanglement swapping with partially entangled states is a particular class of remote entanglement distribution protocols. Here we identify which distributions of states that can or cannot be created by remote entanglement distribution. In particular we prove a powerful theorem that establishes an upper bound on the entanglement of formation that can be produced between two qubit nodes. We extend this result to the case of a linear chain of parties that play the roles of suppliers and nodes; this extension provides

  1. Renormalizing Entanglement Distillation

    Science.gov (United States)

    Waeldchen, Stephan; Gertis, Janina; Campbell, Earl T.; Eisert, Jens

    2016-01-01

    Entanglement distillation refers to the task of transforming a collection of weakly entangled pairs into fewer highly entangled ones. It is a core ingredient in quantum repeater protocols, which are needed to transmit entanglement over arbitrary distances in order to realize quantum key distribution schemes. Usually, it is assumed that the initial entangled pairs are identically and independently distributed and are uncorrelated with each other, an assumption that might not be reasonable at all in any entanglement generation process involving memory channels. Here, we introduce a framework that captures entanglement distillation in the presence of natural correlations arising from memory channels. Conceptually, we bring together ideas from condensed-matter physics—ideas from renormalization and matrix-product states and operators—with those of local entanglement manipulation, Markov chain mixing, and quantum error correction. We identify meaningful parameter regions for which we prove convergence to maximally entangled states, arising as the fixed points of a matrix-product operator renormalization flow.

  2. Entanglement branching operator

    Science.gov (United States)

    Harada, Kenji

    2018-01-01

    We introduce an entanglement branching operator to split a composite entanglement flow in a tensor network which is a promising theoretical tool for many-body systems. We can optimize an entanglement branching operator by solving a minimization problem based on squeezing operators. The entanglement branching is a new useful operation to manipulate a tensor network. For example, finding a particular entanglement structure by an entanglement branching operator, we can improve a higher-order tensor renormalization group method to catch a proper renormalization flow in a tensor network space. This new method yields a new type of tensor network states. The second example is a many-body decomposition of a tensor by using an entanglement branching operator. We can use it for a perfect disentangling among tensors. Applying a many-body decomposition recursively, we conceptually derive projected entangled pair states from quantum states that satisfy the area law of entanglement entropy.

  3. Entanglement without nonlocality

    International Nuclear Information System (INIS)

    Hewitt-Horsman, C.; Vedral, V.

    2007-01-01

    We consider the characterization of entanglement from the perspective of a Heisenberg formalism. We derive a two-party generalized separability criterion, and from this describe a physical understanding of entanglement. We find that entanglement may be considered as fundamentally a local effect, and therefore as a separate computational resource from nonlocality. We show how entanglement differs from correlation physically, and explore the implications of this concept of entanglement for the notion of classicality. We find that this understanding of entanglement extends naturally to multipartite cases

  4. Der Fachbereich Fertigungstechnik der Zukunft

    DEFF Research Database (Denmark)

    Alting, Leo

    1998-01-01

    Forscher sowie für eine industrielle Zusammenarbeit/Beratung eine attraktive Umgebung zu bieten.Im vorliegenden Papier wird ein internes Entwicklungsprojekt, genannt "Der Fachberich der Zukunft", beschrieben. Ausgehend von den Bedürfnissen und Erwartungen der Kunden (Studierende, Einrichtungen der...

  5. Atypische niedrig-traumatische Femurfrakturen – Zusammenhang mit Komorbiditäten, internistischen und knochenspezifischen Therapien // Atypical femoral fractures – comorbidities and association with bone-specific therapies

    Directory of Open Access Journals (Sweden)

    Muschitz Ch

    2016-01-01

    Full Text Available iIntroduction:/i Although atypical femoral fractures (AFF are generally rare events, several studies have indicated a potential link between AFF and long-term bone specific therapies (BST. The aim of this study was to analyze the frequency of AFF and potential associations with prior or ongoing BST. iMethods:/i 8.851 caucasian female and male patients with de novo hip fractures treated in the largest Austrian level 1 trauma center from 2000–2013 were selected. iResults:/i 194 patients with a de novo lowtraumatic subtrochanteric/shaft fractures were identified: 35 atypical and 159 typical fractures. Of these patients, concomitant diseases, medication, previous fractures and survival were retrieved and analyzed. Female patients in both groups were significantly older. The median survival was significantly shorter in patients with AFF (9 vs. 18 months; p 0.0001. Cardiovascular disease, sarcopenia, chronic kidney disease, type 2 diabetes, smoking (past or current history and prevalent fragility fractures were more frequent in AFF patients, as well as the concomitant use of phenprocoumon, furosemide, and sulfonylurea. Though the number of patients with current BST was low in (14.5% both groups, more patients in the AFF group were previously treated with BST (71% vs 49%; p = 0.016, and they received these therapies for a longer time period. iDiscussion:/i A combination of severe comorbidities, long-term pharmaceutical therapies and a history of previous or ongoing BST were associated with an increased individual risk for AFF. p bKurzfassung:/b iEinleitung:/i Atypische Femurfrakturen (AFF sind in der Regel seltene Ereignisse; mehrere Studien haben einen möglichen Zusammenhang zwischen AFF und langfristigen knochenspezifischen Therapien (KST angegeben. Das Ziel dieser Studie war es, die Häufigkeit der AFF und potentielle Assoziationen mit früheren oder laufenden KST zu analysieren. iMethoden:/i Analyse von 8.851 kaukasischen weiblichen und m

  6. Der Sinn der Lehre

    DEFF Research Database (Denmark)

    Beyes, Timon; Steyaert, Chris

    2015-01-01

    Anhand der Beschreibung und Reflexion einer universitären Lehrveranstaltung, die die Erkundung städtischer Affekte und Atmosphären mittels ethnographischer Praktiken zum Inhalt hat, umreißt unser Beitrag eine Pädagogik des Affekts und skizziert ihre Implikationen für den Sinnbegriff und das Theor...

  7. Die Werte der Wertvermittler - Berufliches Rollenselbstverständnis und Weltanschauung von Journalistinnen und Journalisten

    Directory of Open Access Journals (Sweden)

    Andy Kaltenbrunner

    2010-09-01

    Full Text Available Der Beitrag analysiert professionelles Selbstverständnis, Weltanschauungen und ethische Überzeugungen von Journalistinnen und Journalisten in Österreich. Auf Basis aktueller Befragungen und Studien wird die Grundstruktur des journalistischen Wertesystems skizziert und der Zusammenhang mit täglicher Berichterstattung. Der Beitrag diskutiert mögliche Konsequenzen für Zukunft des Journalismus und Qualität der Öffentlichkeit. The article focuses on the professional values, political views and ethical beliefs of Austrian journalists. Based on recent surveys we outline the basic structure of the journalistic value system in Austria and the interdependence of these values and actual reporting and we discuss possible consequences for the future of journalism as a profession and for the quality of the public sphere.

  8. Zur medienpädagogischen Ausbildung von Lehrerinnen und Lehrern. Folgerungen aus der aktuellen lern- und professionstheoretischen Diskussion

    Directory of Open Access Journals (Sweden)

    Sigrid Blömeke

    2001-08-01

    Full Text Available Vor dem Hintergrund neuerer Ansätze in der Lerntheorie und in der Professionstheorie werden Folgerungen für die inhaltliche und die didaktisch- methodische Gestaltung der medienpädagogischen Lehrerausbildung gezogen. Dafür wird in einem ersten Schritt die Frage des Verhältnisses von Wissen und Handeln geklärt und der Wissenserwerb wird als aktiv-konstruierender Prozess beschrieben. Die in diesem Zusammenhang herausgearbeiteten grundsätzlichen Gestaltungsprinzipien werden dann in einem zweiten Schritt auf der Basis einer an den Aufgaben von Lehrerinnen und Lehrern orientierten näheren Bestimmung medienpädagogischer Kompetenz für den Erwerb dieser konkretisiert. In inhaltlich-systematischer Hinsicht steht die kognitive Strukturbildung im Vordergrund, in didaktisch-methodischer Hinsicht wird ein besonderer Akzent auf Fallarbeit gelegt, deren Möglichkeiten auch an-hand eines Beispiels verdeutlicht werden.

  9. Pornographie ist langweilig! Die „Lustmaschinen“ der Philosophie Pornography is Boring! Philosophical “Machines of Desire”

    Directory of Open Access Journals (Sweden)

    Pascal Eitler

    2007-11-01

    Full Text Available Die vorliegende Studie bietet eine überaus ambitionierte philosophische Erörterung der Problematik des modernen Subjekts und seiner Beziehung zur Pornographie. Svenja Flaßpöhler widmet sich in diesem Zusammenhang insbesondere dem Werk des Marquis de Sade und setzt dieses in Beziehung zur aufgeklärten Selbstreflexion einerseits und zum Pornofilm der Gegenwart anderseits.The study at hand is a very ambitious philosophical exposition on the modern subject in relation to pornography. It approaches specifically the work of the Marquis de Sade and places it in relation to enlightened reflections on the self and to contemporary porno films.

  10. Die ästhetische Geburt selbstbefreiter Subjektivität: Hegels dreifache Theorie der klassischen Komödie

    Directory of Open Access Journals (Sweden)

    Hebing Niklas

    2013-01-01

    Full Text Available Eine Theorie der antiken Komödie entwirft Hegel sowohl in seinem frühen Naturrechtsaufsatz, in der Phänomenologie des Geistes als auch in seinen Berliner Vorlesungen über die Ästhetik. In allen drei Ansätzen steht die Komödie in einer engen Beziehung auf die Tragödie und daher im Zusammenhang umfangreicher politischer, religions- und geschichtsphilosophischer Bestimmungen. In dieser Weise kontextualisiert, arbeitet der Aufsatz Hegels Begriff der dramatischen Gattung des Komischen vor dem Hintergrund der allgemeinen geistphilosophischen Kategorien Sittlichkeit und Substantialität als Ende der klassischen Kunst und zugleich als Entstehung der modernen Subjektivität in ihrer freien Selbstbezüglichkeit heraus. Dabei wird immerzu gefragt, wie die absolutgeistigen Entwicklungen auf dem Gebiet des Ästhetischen objektivgeistige Entwicklungen im Bereich von Staat und Gesellschaft, etwa den in der Komödie bewusst werdenden Untergang des Weltzustands der Polis, aufgreifen und reflektieren. Nicht zuletzt die werkgeschichtliche Dimension von der frühen Position Hegels zum reifen System gibt Aufschluss darüber, dass die Komödienform eine ausgezeichnete Gestalt der Kunst ist, Fragen nach den geistphilosophischen Bruchlinien der Modernität zu verhandeln.

  11. Bestimmung der optimalen Array-Apertur für die Ultraschallprüfung von faserverstärkten Kunststoffen

    OpenAIRE

    Kurras, Martin

    2017-01-01

    Für die zerstörungsfreie Prüfung von Kohlenstofffaserverbundwerkstoffen (CFK) wird häufig die Ultraschallprüfung verwendet. Neben dem klassischen Ultraschallverfahren findet dabei auch die Phased Array Technologie Anwendung. Hierbei wird zwischen zwei Verfahren unterschieden: dem handelsüblichen Phased Array oder Conventional Phased Array (CPA) und dem tomographischen Sampling Phased Array (SPA). Der Einsatz von Phased Arrays im Zusammenhang mit Linear-Scan-Technik und das sich daraus ergeben...

  12. Der Einfluss unterschiedlicher Prophylaxepulver auf die adhäsive Verbundfestigkeit von Etch&Rinse- und Self-Etch-Adhäsiven

    OpenAIRE

    Schwientek, Kathrin

    2011-01-01

    Das Hauptziel dieser Studie bestand darin zu untersuchen, inwiefern der Einsatz von Prophylaxepulvern die adhäsive Performance von Dentinhaftvermittlern beeinflusst. Zusätzlich wurden unterschiedliche Bondingsysteme bezüglich ihrer adhäsiven Verbundfestigkeit im Mikrozugverfahren miteinander verglichen und bewertet. Zehn unterschiedliche Adhäsivsysteme, die verschiedene Bondingphilosophien repräsentieren, wurden getestet. In diesem Zusammenhang kamen zwei unterschiedliche Prophylaxepulver (Pr...

  13. Der Einfluss von personeller Einkommensverteilung auf die „Great Depression“ und die „Great Recession“

    Directory of Open Access Journals (Sweden)

    Stefan Trappl

    2015-12-01

    Full Text Available Der Einfluss gestiegener Einkommensungleichheit auf die „Great Depression“ und die „Great Recession“ wurde mehrfach postuliert (Galbraith 1954/2009; Eccles 1951; Rajan 2010; Stiglitz 2012; Piketty 2014. Konkrete empirische Arbeiten zum Zusammenhang zwischen Einkommensverteilung und dem Entstehen von Wirtschaftskrisen gibt es aber bislang wenige. Kumhof/Ranciere (2010 überprüften die von Rajan (2010 aufgestellte Hypothese, die einen entsprechenden Zusammenhang postuliert, mittels Modellrechnung. Bordo/Meissner (2012 und darauf aufbauend Gu/Huang (2014 verwendeten unterschiedliche Regressionsmodelle in Bezug auf einen entsprechenden Zusammenhang, ohne jedoch eindeutige Ergebnisse zu liefern. Die vorliegende Arbeit schließt an diese Arbeiten an, beschränkt die Untersuchung allerdings auf Staaten, für die Daten für die letzten hundert Jahre verfügbar sind, und untersucht zudem explizit die Zeiträume um die beiden größten Krisen der letzten hundert Jahre, die „Great Depression“ und die „Great Recession“. Die Auswertungen zeigen, dass die personelle Einkommensverteilung ein guter Prädiktor für die Kriseneintrittswahrscheinlichkeit ist.

  14. Non-Markovian dynamics, decoherence and entanglement in dissipative quantum systems with applications to quantum information theory of continuous variable systems; Nicht-Markovsche Dynamik, Dekohaerenz und Verschraenkung in dissipativen Quantensystemen mit Anwendung in der Quanteninformationstheorie von Systemen kontinuierlicher Variablen

    Energy Technology Data Exchange (ETDEWEB)

    Hoerhammer, C.

    2007-11-26

    In this thesis, non-Markovian dynamics, decoherence and entanglement in dissipative quantum systems are studied. In particular, applications to quantum information theory of continuous variable systems are considered. The non-Markovian dynamics are described by the Hu-Paz-Zhang master equation of quantum Brownian motion. In this context the focus is on non-Markovian effects on decoherence and separability time scales of various single- mode and two-mode continuous variable states. It is verified that moderate non-Markovian influences slow down the decay of interference fringes and quantum correlations, while strong non-Markovian effects resulting from an out-of-resonance bath can even accelerate the loss of coherence, compared to predictions of Markovian approximations. Qualitatively different scenarios including exponential, Gaussian or algebraic decay of the decoherence function are analyzed. It is shown that partial recurrence of coherence can occur in case of non-Lindblad-type dynamics. The time evolution of quantum correlations of entangled two-mode continuous variable states is examined in single-reservoir and two-reservoir models, representing noisy correlated or uncorrelated non-Markovian quantum channels. For this purpose the model of quantum Brownian motion is extended. Various separability criteria for Gaussian and non-Gaussian continuous variable systems are applied. In both types of reservoir models moderate non-Markovian effects prolong the separability time scales. However, in these models the properties of the stationary state may differ. In the two-reservoir model the initial entanglement is completely lost and both modes are finally uncorrelated. In a common reservoir both modes interact indirectly via the coupling to the same bath variables. Therefore, new quantum correlations may emerge between the two modes. Below a critical bath temperature entanglement is preserved even in the steady state. A separability criterion is derived, which depends

  15. Der Einfluss von rechtsgerichtetem Autoritarismus und sozialer Dominanzorientierung auf homophobe Einstellungen

    Directory of Open Access Journals (Sweden)

    Sarah Andrejewski

    2016-06-01

    Full Text Available Das Thema Homophobie geriet seit 2012 verstärkt in das Interesse der Medien. Ursachen waren u.a. die Erlassung homophober Gesetze in Russland, Outings von prominenten Persönlichkeiten wie Fußballspieler und Politiker oder die in Frankreich auftretenden Massendemonstrationen zur Verhinderung der gleichgeschlechtlichen Ehe. Durch das kürzlich stattfindende Attentat in einem beliebten Club der LGBT-Community in Orlando ist das Thema präsenter denn je. Neben Untersuchungen, die aufdecken, welchen Vorurteilen Menschen mit einer homosexuellen Ausrichtung ausgesetzt sind und wie sich diese im Alltag der Betroffenen niederschlagen, suchen vermehrt Studien nach den Gründen dieser Vorurteile. Die vorliegende Arbeit bedient sich dazu etablierter Konzepte aus der Vorurteilsforschung, um diese in einen Zusammenhang mit homophoben Einstellungen und Verhaltensweisen zu bringen. Mithilfe einer Online-Befragung von 249 heterosexuellen Teilnehmern wurde der Einfluss von rechtsgerichteten Autoritarismus (RWA, sozialer Dominanzorientierung (SDO und sozialer Identität (SI auf homophobe Einstellungen ermittelt. Es konnte nachgewiesen werden, dass die untersuchten Variablen negativ auf die Einstellungen der Untersuchungsteilnehmer gegenüber Schwulen und Lesben wirken. Gleichzeitig wurde die Mediatorrolle der sozialen Identität als Identifikation mit der eigenen heterosexuellen Orientierung getestet und nachgewiesen, dass diese als Mediator zwischen RWA, SDO und homophoben Einstellungen fungiert.

  16. Theory of rubber friction and traction properties of car tyres; Theorie der Gummireibung und Traktionseigenschaften von Reifen

    Energy Technology Data Exchange (ETDEWEB)

    Klueppel, M.; Alshuth, T.; Schuster, R.H. [Deutsches Inst. fuer Kautschuktechnologie e.V., Hannover (Germany)

    1998-12-31

    ABS braking on dry and wet roads involves different mechanisms of rubber friction on rough surfaces. This improves car safety in terms of higher manoeuvrability and shorter braking lengths especially on wet roads. Current research focuses on optimisation of tyrecontact surface materials with better traction characteristics and lower rolling resistance. Laboratory predictions of the traction properties of tyre faces must be based on fundamental knowledge of the local sliding phenomena in the tyre contact surface and the resulting energy dissipation during ABS braking. This contribution therefore attempts to relate the elementary mechanisms of tyre mechanics in ABS braking processes to theoretical concepts of rubber friction on rough surfaces. [Deutsch] Beim ABS-Bremsen auf trockenen und nassen Strassen werden unterschiedliche Mechanismen der Gummireibung auf rauhen Oberflaechen wirksam. In der Summe bewirkt dies eine hoehere Fahrsicherheit, da neben der Manoevrierfaehigkeit des Autos auch der Bremsweg, vor allem auf nassen Strassen, verkuerzt sein kann. In diesem Zusammenhang wird zur Zeit verstaerkt an einer Optimierung von Laufflaechenmaterialien durch den Einsatz von massgeschneiderten Loesungs-SBR-Typen in Verbindung mit gefaellten Kieselsaeuren gearbeitet, wodurch neben einer Verbesserung der Traktionseigenschaften beim ABS-Bremsen auch eine Verringerung des Rollwiderstandes erreicht wird. Fuer Laborvorhersagen der Traktionseigenschaften von Reifenlaufflaechen ist ein grundlegendes Verstaendnis der lokalen Gleitphaenomene in der Reifenaufstandsflaeche und der damit verbundenen Energiedissipation beim ABS-Bremsen erforderlich. In dieser Arbeit wird deshalb angestrebt, die elementaren Mechanismen der Reifenmechanik beim ABS-Bremsen mit theoretischen Konzepten der Gummireibung auf rauhen Oberflaechen in Verbindung zu bringen. (orig.)

  17. Majorana entanglement bridge

    Science.gov (United States)

    Plugge, Stephan; Zazunov, Alex; Sodano, Pasquale; Egger, Reinhold

    2015-06-01

    We study the concurrence of entanglement between two quantum dots in contact to Majorana bound states on a floating superconducting island. The distance between the Majorana states, the charging energy of the island, and the average island charge are shown to be decisive parameters for the efficiency of entanglement generation. We find that long-range entanglement with basically distance-independent concurrence is possible over wide parameter regions, where the proposed setup realizes a "Majorana entanglement bridge." We also study the time-dependent concurrence obtained after one of the tunnel couplings is suddenly switched on, which reveals the time scales for generating entanglement. Accurate analytical expressions for the concurrence are derived both for the static and the time-dependent cases. Our results indicate that entanglement formation in interacting Majorana devices can be fully understood in terms of an interplay of elastic cotunneling (also referred to as "teleportation") and crossed Andreev reflection processes.

  18. Geometric multipartite entanglement measures

    International Nuclear Information System (INIS)

    Paz-Silva, Gerardo A.; Reina, John H.

    2007-01-01

    Within the framework of constructions for quantifying entanglement, we build a natural scenario for the assembly of multipartite entanglement measures based on Hopf bundle-like mappings obtained through Clifford algebra representations. Then, given the non-factorizability of an arbitrary two-qubit density matrix, we give an alternate quantity that allows the construction of two types of entanglement measures based on their arithmetical and geometrical averages over all pairs of qubits in a register of size N, and thus fully characterize its degree and type of entanglement. We find that such an arithmetical average is both additive and strongly super additive

  19. Remarks on entanglement swapping

    International Nuclear Information System (INIS)

    Song, Daegene

    2004-01-01

    In two partially entangled states, entanglement swapping by Bell measurement will yield the weaker entanglement of the two. This scheme is optimal because the average entanglement cannot increase under local operation and classical communication. However, for more than two states, this scheme does not always yield the weakest link. We consider projective measurements other than Bell-type measurement and show, numerically, that while Bell measurement may not be unique, it is indeed optimal among these projective measurements. We also discuss the non-uniqueness of Bell measurements. (letter to the editor)

  20. The step from the project control to long-distance control; Von der Projekt- zur Fernkontrolle

    Energy Technology Data Exchange (ETDEWEB)

    Kaelin, W. [Ingenieurbuero Werner Kaelin, Schwyz (Switzerland)

    1995-12-31

    In chapter 8 of the anthology about building control the extension from project control to long-distance control is described. The following aspects are discussed: guidelines (operating concept, task anthology), project (implementation, control, documentation), realisation (initiation, example), operation (regional co-operation, characteristic numbers). (BWI) [Deutsch] Kapitel 8 des Sammelbandes ueber Building Control ist dem Ausbau von der Projekt- zur Fernkontrolle gewidmet. In diesem Zusammenhang werden folgende Themen angesprochen: Vorgaben (Betriebskonzept, Pflichtenheft), Projekt (Umsetzung, Kontrolle, Dokumentation), Ausfuehrung (Inbetriebsetzung, Beispiel); Betrieb (regionaler Zusammenschluss, Kennzahlen). (BWI)

  1. Maximally multipartite entangled states

    Science.gov (United States)

    Facchi, Paolo; Florio, Giuseppe; Parisi, Giorgio; Pascazio, Saverio

    2008-06-01

    We introduce the notion of maximally multipartite entangled states of n qubits as a generalization of the bipartite case. These pure states have a bipartite entanglement that does not depend on the bipartition and is maximal for all possible bipartitions. They are solutions of a minimization problem. Examples for small n are investigated, both analytically and numerically.

  2. Radiation-induced muscositis and neutrophil granulocytes in oral mucosa; Strahleninduzierte Mukositis und neutrophile Granulozyten in der Mundschleimhaut

    Energy Technology Data Exchange (ETDEWEB)

    Schmidberger, H.; Rave-Fraenk, M.; Kim, S.; Hille, A.; Pradier, O.; Hess, C.F. [Klinik fuer Strahlentherapie und Radioonkologie, Univ. Goettingen (Germany)

    2003-10-01

    Background: Chemotherapy-induced mucositis can be related to a decrease in oral neutrophils. We tested the relationship between radiation-induced mucositis and oral neutrophil counts. Patients and Methods: Oral neutrophil counts were obtained for ten patients with head and neck cancer who received radiotherapy of the pharynx and oral cavity. Four patients received additional chemotherapy (5-FU, Mitomycin). Counts were obtained before and during treatment; four healthy volunteers were included in the study as well. For evaluation, a quantitative mouth rinse assay, including neutrophil-staining with acridin-orange, was applied. Results: We observed large inter-individual variations with respect to neutrophil counts for patients and control persons (Table 1). During treatment (irradiation or chemoirradiation), large intra-individual variations were seen additionally (Figure 1). We found a correlation between neutrophil counts and clinical reaction grade. Neutrophil counts increased with increasing mucositis (Figure 2). This increase was more pronounced for patients treated with chemoirradiation compared to radiation alone. Treatment breaks at weekends had no clear influence on neutrophil counts. Conclusions: We observed a weak correlation between neutrophil counts and clinical reaction grade. However, the variations in neutrophil counts are too large to utilize this parameter as a surrogate for clinical mucositis grading. The assumption that a decrease in oral neutrophils is associated with radiation-induced mucositis was clearly negated. (orig.) [German] Hintergrund: Die chemotherapieinduzierte Mukositis kann mit einer Verarmung der Mundschleimhaut an neutrophilen Granulozyten vergesellschaftet sein. Wir ueberprueften den Zusammenhang zwischen der radiogenen Mukositis und der Anzahl neutrophiler Granulozyten. Patienten und Methoden: Bei zehn Patienten mit Tumoren der Kopf-Hals-Region, die sich einer Strahlentherapie unterzogen, wurde die Anzahl enoraler neutrophiler

  3. Extraprostatische Expansion des Prostatakarzinoms und seine Beziehung zu den Resektionsrändern bei der radikalen Prostatektomie aus Sicht des Pathologen

    Directory of Open Access Journals (Sweden)

    Noll P

    2008-01-01

    Full Text Available Das Prostatakarzinom stellt heute in der westlichen Welt das am häufigsten diagnostizierte Karzinom beim Mann dar. Entsprechend dieser Häufigkeit werden zunehmend radikale Prostatektomien durchgeführt. Die histologische Aufarbeitung des Operationspräparates liefert dem Urologen die wichtigsten Prognosefaktoren des Prostatakarzinoms. Hierbei besteht ein enger Zusammenhang zwischen der extraprostatischen Ausdehnung des Tumors und seiner Beziehung zu den Resektionsrändern. Anhand einer eigenen Untersuchung an 200 radikal operierten Prostatakarzinomen konnte gezeigt werden, dass hierbei die Lokalisation, der Malignitätsgrad und die Größe des Tumors entscheidende Bedeutung haben. Die Ermittlung dieser Parameter ist abhängig von einer standardisierten Untersuchungstechnik auf der Grundlage einer vollständigen histologischen Aufarbeitung der Prostata.

  4. Cabling in buildings -neutrally applicable, structured. Domination of the future multitude of data; Gebaeudeverkabelung - anwendungsneutral, strukturiert. Beherrschung der Datenmengen von morgen

    Energy Technology Data Exchange (ETDEWEB)

    Oehler, A.M. [Fachhochschule Reutlingen (Germany)

    1995-12-31

    In chapter 19 of the anthology about building control neutrally applicable and structured cabling in buildings is described. The aim is to dominate the future multitude of data. The following aspects are discussed: demands on neutrally applicable cabling, neutrally applicable cabling topology, neutrally applicable media, Integrated Communications Cabling System. (orig.) [Deutsch] Kapitel 19 des Sammelbandes ueber Buidling Control ist dem Themenbereich der anwendungsneutralen und strukturierten Gebaeudeverkabelung gewidmet. Ziel ist die Beherrschung der Datenmengen von morgen. In diesem Zusammenhang werden folgende Themen angesprochen: Forderungen an die anwendungsneutrale Verkabelung; Anwendungsneutrale Verkabelungstopologie; Anwendungsneutrale Medien; ICCS Integrades Communications Cabling System. (BWI)

  5. Multi-photon entanglements

    International Nuclear Information System (INIS)

    Daniell, M.L.

    2000-09-01

    The motivation of this thesis was to create higher-order entanglements. The first experimental observation of a four-photon entanglement was presented in the experiment of this thesis. And the visibility of this entanglement was 0.79+-0.06, which is sufficient to make claims of the nonlocality of quantum mechanics. This therefore lays a foundation for experiments showing the nonlocality of teleportation, and the purification of entanglement. The work of this thesis brings together a lot of earlier work done by the Zeilinger Group, and lays a foundation for future experiments. Earlier experiments such as teleportation together with entanglement swapping, which are 'complete teleportation' in as much as the state teleported is entirely undefined, can be combined and re-done with this four-photon entanglement. This result would be the first demonstration of complete, nonlocal teleportation. Also this experiment can be slightly modified and used to perform the first experimental quantum purification of entanglement, which is of vital importance to the fields of quantum information, and also is interesting for fundamental experiments on entanglement. Another direct application of this experiment is to perform the first 'event-ready' testing of Bell's Inequality. Here the four-photon entanglement can be used as a source of entangled photons, whereby the photons have no common source. This would enable an even more stringent testing of Bells theorem. Finally this experiment can be used for the demonstration and investigation of many practical, directly applicable quantum information schemes. For instance quantum cryptography, error correction, and computing. (author)

  6. Entanglement negativity in the multiverse

    Energy Technology Data Exchange (ETDEWEB)

    Kanno, Sugumi [Department of Theoretical Physics and History of Science, University of the Basque Country UPV/EHU, 48080 Bilbao (Spain); Shock, Jonathan P. [Laboratory for Quantum Gravity and Strings and Astrophysics, Cosmology and Gravity Center, Department of Mathematics and Applied Mathematics, University of Cape Town, Private Bag, Rondebosch 7701 (South Africa); Soda, Jiro, E-mail: sugumi.kanno@ehu.es, E-mail: jonathan.shock@uct.ac.za, E-mail: jiro@phys.sci.kobe-u.ac.jp [Department of Physics, Kobe University, Kobe 657-8501 (Japan)

    2015-03-01

    We explore quantum entanglement between two causally disconnected regions in the multiverse. We first consider a free massive scalar field, and compute the entanglement negativity between two causally separated open charts in de Sitter space. The qualitative feature of it turns out to be in agreement with that of the entanglement entropy. We then introduce two observers who determine the entanglement between two causally disconnected de Sitter spaces. When one of the observers remains constrained to a region of the open chart in a de Sitter space, we find that the scale dependence enters into the entanglement. We show that a state which is initially maximally entangled becomes more entangled or less entangled on large scales depending on the mass of the scalar field and recovers the initial entanglement in the small scale limit. We argue that quantum entanglement may provide some evidence for the existence of the multiverse.

  7. Entanglement negativity in the multiverse

    International Nuclear Information System (INIS)

    Kanno, Sugumi; Shock, Jonathan P.; Soda, Jiro

    2015-01-01

    We explore quantum entanglement between two causally disconnected regions in the multiverse. We first consider a free massive scalar field, and compute the entanglement negativity between two causally separated open charts in de Sitter space. The qualitative feature of it turns out to be in agreement with that of the entanglement entropy. We then introduce two observers who determine the entanglement between two causally disconnected de Sitter spaces. When one of the observers remains constrained to a region of the open chart in a de Sitter space, we find that the scale dependence enters into the entanglement. We show that a state which is initially maximally entangled becomes more entangled or less entangled on large scales depending on the mass of the scalar field and recovers the initial entanglement in the small scale limit. We argue that quantum entanglement may provide some evidence for the existence of the multiverse

  8. Entanglement negativity in the multiverse

    Energy Technology Data Exchange (ETDEWEB)

    Kanno, Sugumi [Department of Theoretical Physics and History of Science, University of the Basque Country UPV/EHU, 48080 Bilbao (Spain); IKERBASQUE, Basque Foundation for Science, Maria Diaz de Haro 3, 48013, Bilbao (Spain); Laboratory for Quantum Gravity & Strings and Astrophysics, Cosmology & Gravity Center, Department of Mathematics & Applied Mathematics, University of Cape Town, Private Bag, Rondebosch 7701 (South Africa); Shock, Jonathan P. [Laboratory for Quantum Gravity & Strings and Astrophysics, Cosmology & Gravity Center, Department of Mathematics & Applied Mathematics, University of Cape Town, Private Bag, Rondebosch 7701 (South Africa); National Institute for Theoretical Physics, Private Bag X1, Matieland, 7602 (South Africa); Soda, Jiro [Department of Physics, Kobe University, Kobe 657-8501 (Japan)

    2015-03-10

    We explore quantum entanglement between two causally disconnected regions in the multiverse. We first consider a free massive scalar field, and compute the entanglement negativity between two causally separated open charts in de Sitter space. The qualitative feature of it turns out to be in agreement with that of the entanglement entropy. We then introduce two observers who determine the entanglement between two causally disconnected de Sitter spaces. When one of the observers remains constrained to a region of the open chart in a de Sitter space, we find that the scale dependence enters into the entanglement. We show that a state which is initially maximally entangled becomes more entangled or less entangled on large scales depending on the mass of the scalar field and recovers the initial entanglement in the small scale limit. We argue that quantum entanglement may provide some evidence for the existence of the multiverse.

  9. Mutual preservation of entanglement

    International Nuclear Information System (INIS)

    Veitia, Andrzej; Jing, Jun; Yu, Ting; Wong, Chee Wei

    2012-01-01

    We study a generalized double Jaynes–Cummings (JC) model where two entangled pairs of two-level atoms interact indirectly. We show that there exist initial states of the qubit system so that two entangled pairs are available at all times. In particular, the minimum entanglement in the pairs as a function of the initial state is studied. Finally, we extend our findings to a model consisting of multi-mode atom–cavity interactions. We use a non-Markovian quantum state diffusion (QSD) equation to obtain the steady-state density matrix for the qubits. We show that the multi-mode model also displays dynamical preservation of entanglement. -- Highlights: ► Entanglement dynamics is studied in a generalized double Jaynes–Cummings model. ► We show that for certain initial states, the atoms remain entangled at all times. ► We extend the results to the case of multi-mode atom–cavity interactions. ► The model suggest that indirect interaction may help to preserve entanglement.

  10. Causes of seasonal variations of Cs-134/137 activity concentrations in surface air; Ursachen der jahreszeitlichen Schwankungen der Aktivitaetskonzentrationen von Cs-134/137 in der bodennahen Luft

    Energy Technology Data Exchange (ETDEWEB)

    Hoetzl, H. [GSF - Forschungszentrum fuer Umwelt und Gesundheit Neuherberg GmbH, Oberschleissheim (Germany). Inst. fuer Strahlenschutz; Winkler, R. [GSF - Forschungszentrum fuer Umwelt und Gesundheit Neuherberg GmbH, Oberschleissheim (Germany). Inst. fuer Strahlenschutz

    1993-12-31

    In winter months maxima of Cs-134/137 activity concentrations in air are observed at several locations in Europe. To clarify this phenomenon, from October 1991 to November 1992 we performed a program for aerosol collection on a short-term scale based on collecting intervals of 48-72 hours. The local meteorological parameters were determined simultaneously. Statistical analysis of these observations reveiled a highly significant positive correlation between Cs-137 activity concentration and the so-called `Stagnationsindex`. Based on this relationship the seasonal variations of Cs-134/137 concentrations in ground-level air can be explained by atmospheric inversion conditions frequently occurring during fall- and wintermonths. (orig.) [Deutsch] Zur Klaerung der an verschiedenen Orten Europas in den Wintermonaten beobachteten Maxima der Cs-134/137-Aktivitaetskonzentrationen in der bodennahen Luft wurde von Oktober 1991 bis November 1992 ein Messgrogramm mit relativ kurzen Zeitintervallen fuer die Aerosolsammlung (48-72 Stunden) durchgefuehrt. Gleichzeitig wurden lokale meteorologische Parameter miterfasst. Die statistische Auswertung der Messergebnisse lieferte eine hochsignifikante positive Korrelation zwischen der Aktivitaetskonzentration von Cs-137 und dem sog. Stagnationsindex. Auf Grund dieses Zusammenhangs lassen sich die saisonalen Schwankungen der Cs-134/137-Luftkonzentrationen mit dem haeufigen Auftreten von austauscharmen Wetterlagen in den Herbst- und Wintermonaten erklaeren. (orig.)

  11. Multiple-copy entanglement transformation and entanglement catalysis

    International Nuclear Information System (INIS)

    Duan Runyao; Feng Yuan; Li Xin; Ying Mingsheng

    2005-01-01

    We prove that any multiple-copy entanglement transformation [S. Bandyopadhyay, V. Roychowdhury, and U. Sen, Phys. Rev. A 65, 052315 (2002)] can be implemented by a suitable entanglement-assisted local transformation [D. Jonathan and M. B. Plenio, Phys. Rev. Lett. 83, 3566 (1999)]. Furthermore, we show that the combination of multiple-copy entanglement transformation and the entanglement-assisted one is still equivalent to the pure entanglement-assisted one. The mathematical structure of multiple-copy entanglement transformations then is carefully investigated. Many interesting properties of multiple-copy entanglement transformations are presented, which exactly coincide with those satisfied by the entanglement-assisted ones. Most interestingly, we show that an arbitrarily large number of copies of state should be considered in multiple-copy entanglement transformations

  12. Schriftstellerinnen der DDR und feministisches Bewußtsein im Staatssozialismus

    Directory of Open Access Journals (Sweden)

    Eva Kaufmann

    2001-11-01

    Full Text Available Seit den 1960er Jahren produzierten Schriftstellerinnen in der DDR wie Christa Wolf, Irmtraud Morgner, Sarah Kirsch, Brigitte Reimann, Charlotte Worgitzky, Lia Pirskawetz, und Maya Wiens eine vielfältige Literatur zu frauenrelevanten Themen. Den Obertitel „The Promised Land“ (das gelobte Land hat Lorna Martens Irmtraud Morgner entlehnt, der Autorin, die sie neben Christa Wolf als wichtigste Zeugin für „feminist writing“ in der DDR betrachtet. In Morgners Roman Leben und Abenteuer der Trobadora Beatriz steht der Begriff „gelobtes Land“ bezogen auf die DDR in einem ironischen Zusammenhang. Mit simplem Jaja oder Neinnein ist diesem „Ort des Wunderbaren“ (Morgner nicht beizukommen. Vergleichbares signalisiert auch das Fragezeichen, das Martens hinter den Begriff „Promised Land“ setzt. Der anspielungsreiche Verweis auf das Land erscheint auch insofern nützlich, als die Eigenart feministischen Schreibens genauer zu fassen ist, wenn über das Land selbst, namentlich seine Frauenpolitik, Auskünfte gegeben werden. Lorna Martens möchte herausfinden, wie Schriftstellerinnen in der DDR feministisches Bewusstsein artikuliert haben, d.h. feministisches Bewusstsein unter den vom Staatssozialismus geschaffenen Bedingungen.

  13. Holographic Entanglement Entropy

    CERN Document Server

    Rangamani, Mukund

    2016-01-01

    We review the developments in the past decade on holographic entanglement entropy, a subject that has garnered much attention owing to its potential to teach us about the emergence of spacetime in holography. We provide an introduction to the concept of entanglement entropy in quantum field theories, review the holographic proposals for computing the same, providing some justification for where these proposals arise from in the first two parts. The final part addresses recent developments linking entanglement and geometry. We provide an overview of the various arguments and technical developments that teach us how to use field theory entanglement to detect geometry. Our discussion is by design eclectic; we have chosen to focus on developments that appear to us most promising for further insights into the holographic map. This is a preliminary draft of a few chapters of a book which will appear sometime in the near future, to be published by Springer. The book in addition contains a discussion of application o...

  14. Entanglement in neutrino oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Blasone, M.; Dell' Anno, F.; De Siena, S.; Illuminati, F. [Universita degli Studi di Salerno Via Ponte don Melillon, Dipt. di Matematica e Informatica, Fisciano SA (Italy); INFN Sezione di Napoli, Gruppo collegato di Salerno - Baronissi SA (Italy); Dell' Anno, F.; De Siena, S.; Illuminati, F. [CNR-INFM Coherentia - Napoli (Italy); Blasone, M. [ISI Foundation for Scientific Interchange, Torino (Italy)

    2009-03-15

    Flavor oscillations in elementary particle physics are related to multimode entanglement of single-particle states. We show that mode entanglement can be expressed in terms of flavor transition probabilities, and therefore that single-particle entangled states acquire a precise operational characterization in the context of particle mixing. We treat in detail the physically relevant cases of two- and three-flavor neutrino oscillations, including the effective measure of CP violation. We discuss experimental schemes for the transfer of the quantum information encoded in single-neutrino states to spatially delocalized two-flavor charged-lepton states, thus showing, at least in principle, that single-particle entangled states of neutrino mixing are legitimate physical resources for quantum information tasks. (authors)

  15. Entanglement in neutrino oscillations

    International Nuclear Information System (INIS)

    Blasone, M.; Dell'Anno, F.; De Siena, S.; Illuminati, F.; Dell'Anno, F.; De Siena, S.; Illuminati, F.; Blasone, M.

    2009-01-01

    Flavor oscillations in elementary particle physics are related to multimode entanglement of single-particle states. We show that mode entanglement can be expressed in terms of flavor transition probabilities, and therefore that single-particle entangled states acquire a precise operational characterization in the context of particle mixing. We treat in detail the physically relevant cases of two- and three-flavor neutrino oscillations, including the effective measure of CP violation. We discuss experimental schemes for the transfer of the quantum information encoded in single-neutrino states to spatially delocalized two-flavor charged-lepton states, thus showing, at least in principle, that single-particle entangled states of neutrino mixing are legitimate physical resources for quantum information tasks. (authors)

  16. Witnessing entanglement by proxy

    International Nuclear Information System (INIS)

    Bäuml, Stefan; Bruß, Dagmar; Kampermann, Hermann; Huber, Marcus; Winter, Andreas

    2016-01-01

    Entanglement is a ubiquitous feature of low temperature systems and believed to be highly relevant for the dynamics of condensed matter properties and quantum computation even at higher temperatures. The experimental certification of this paradigmatic quantum effect in macroscopic high temperature systems is constrained by the limited access to the quantum state of the system. In this paper we show how macroscopic observables beyond the mean energy of the system can be exploited as proxy witnesses for entanglement detection. Using linear and semi-definite relaxations we show that all previous approaches to this problem can be outperformed by our proxies, i.e. entanglement can be certified at higher temperatures without access to any local observable. For an efficient computation of proxy witnesses one can resort to a generalised grand canonical ensemble, enabling entanglement certification even in complex systems with macroscopic particle numbers. (paper)

  17. Entangled Cloud Storage

    DEFF Research Database (Denmark)

    Ateniese, Giuseppe; Dagdelen, Özgür; Damgård, Ivan Bjerre

    2012-01-01

    keeps the files in it private but still lets each client P_i recover his own data by interacting with S; no cooperation from other clients is needed. At the same time, the cloud provider is discouraged from altering or overwriting any significant part of c as this will imply that none of the clients can......Entangled cloud storage enables a set of clients {P_i} to “entangle” their files {f_i} into a single clew c to be stored by a (potentially malicious) cloud provider S. The entanglement makes it impossible to modify or delete significant part of the clew without affecting all files in c. A clew...... recover their files. We provide theoretical foundations for entangled cloud storage, introducing the notion of an entangled encoding scheme that guarantees strong security requirements capturing the properties above. We also give a concrete construction based on privacy-preserving polynomial interpolation...

  18. Transplanckian entanglement entropy

    International Nuclear Information System (INIS)

    Chang, Darwin; Chu, C.-S.; Lin Fengli

    2004-01-01

    The entanglement entropy of the event horizon is known to be plagued by the UV divergence due to the infinitely blue-shifted near horizon modes. In this Letter we calculate the entanglement entropy using the transplanckian dispersion relation, which has been proposed to model the quantum gravity effects. We show that, very generally, the entropy is rendered UV finite due to the suppression of high energy modes effected by the transplanckian dispersion relation

  19. Multipartite entanglement and firewalls

    Science.gov (United States)

    Luo, Shengqiao; Stoltenberg, Henry; Albrecht, Andreas

    2017-03-01

    Black holes offer an exciting area to explore the nature of quantum gravity. The classic work on Hawking radiation indicates that black holes should decay via quantum effects, but our ideas about how this might work at a technical level are incomplete. Recently Almheiri-Marolf-Polchinski-Sully (AMPS) have noted an apparent paradox in reconciling fundamental properties of quantum mechanics with standard beliefs about black holes. One way to resolve the paradox is to postulate the existence of a "firewall" inside the black hole horizon which prevents objects from falling smoothly toward the singularity. A fundamental limitation on the behavior of quantum entanglement known as "monogamy" plays a key role in the AMPS argument. Our goal is to study and apply many-body entanglement theory to consider the entanglement among different parts of Hawking radiation and black holes. Using the multipartite entanglement measure called negativity, we identify an example which could change the AMPS accounting of quantum entanglement and perhaps eliminate the need for a firewall. Specifically, we constructed a toy model for black hole decay which has different entanglement behavior than that assumed by AMPS. We discuss the additional steps that would be needed to bring lessons from our toy model to our understanding of realistic black holes.

  20. Editorial: Visuelle Methoden in der Forschung

    Directory of Open Access Journals (Sweden)

    Horst Niesyto

    2005-06-01

    Full Text Available Die Bedeutung der Bilder in der öffentlichen Kommunikation hat in den letzten Jahren stark zugenommen. Nicht umsonst spricht William Mitchell in seinem Buch «Picture Theory» (1994 von einem «pictorial turn», der sich an den «linguistic turn» anschliesse. Er konstatiert programmatisch: «we may find that the problem of the twenty-first century is the problem of the image». Betrachtet man den Bereich der erziehungs- und sozialwissenschaftlichen Forschung unter der Perspektive, welche Bedeutung hier visuellem Material zukommt, dann stellt man nüchtern fest, dass in den Bereichen der Datenerhebung wie auch der Datenauswertung in methodologischer wie auch in methodischer Hinsicht Defizite bestehen. Das gilt für qualitative wie auch für quantitative Forschungsmethoden gleichermassen. Die wesentlichen Fortschritte qualitativer Methoden in den letzten dreissig Jahren sind beispielsweise vor allem mit neuen Entwicklungen im Bereich der Interpretation von Texten (Interviews, Gruppendiskussion, ethnografische Verfahren verbunden. Sie stehen im Zusammenhang mit dem «linguistic turn» in den Sozialwissenschaften (konversations- und narrationsanalytische Auswertungsverfahren und gehen einher mit einer Marginalisierung der Interpretation visueller Dokumente. Bilder wurden wesentlich auch als Texte gesehen («Die Welt als Text». Artikulation und kommunikative Verständigung vollziehen sich aber nicht nur im Medium der Sprache und des Textes, sondern auch in demjenigen des Bildes bzw. bewegter Bilder (Film. Die Methoden zum Sprach- und Textverstehen sind relativ gut ausgearbeitet, die Methoden zur Film- und Bildinterpretation sind es im Kontext sozialwissenschaftlicher Forschung nicht. Natürlich gibt es ausgearbeitete Traditionen für die Bildinterpretation im Bereich der Kunstwissenschaft und für Filminterpretation im Bereich der Filmwissenschaft, aber hier liegen andere Fragestellungen zugrunde. Seit einigen Jahren hat eine stärkere Hinwendung

  1. Mediengewalt und Aggression : eine längsschnittliche Betrachtung des Zusammenhangs am Beispiel des Konsums gewalthaltiger Bildschirmspiele

    OpenAIRE

    Möller, Ingrid

    2006-01-01

    In einer Längsschnittstudie wurde untersucht, inwieweit sich die regelmäßige Beschäftigung mit dem Medium der gewalthaltigen Bildschirmspiele auf aggressionsbegünstigende Kognitionen und die Aufrechterhaltung einer aggressiven Persönlichkeitsdisposition auswirkt. Es wurden insgesamt N = 349 Mädchen und Jungen im Alter von 12 bis 16 Jahren im Abstand von sechs Monaten zweimal zu ihrem Konsum von und der Präferenz für gewalthaltige Bildschirmspiele sowie zu normativen Überzeugung bzgl. der Ange...

  2. Transparent thermal insulation - new developments in the field of building technology?; Transparente Waermedaemmung - neue Trends in der Gebaeudetechnik?

    Energy Technology Data Exchange (ETDEWEB)

    Bieler, P.

    1995-12-31

    In chapter 10 of the anthology about building control transparent thermal insulation is described as a possible new trend in the field of building technology. An answer is given to the question to which extent facades can be applied as technical building equipment. Furthermore the passive use of solar energy is discussed and the measuring results of a test cell building are presented. (BWI) [Deutsch] Kapitel 10 des Sammelbandes ueber Building Control stellt die transparente Waermedaemmung als moeglichen neuen Trend der Gebaeudetechnik vor. In diesem Zusammenhang wird die Frage aufgeworfen, inwieweit Fassaden als Technische Gebaeudeausruestung eingesetzt und angesehen werden koennen. Ferner werden die passive Solarenergienutzungen angesprochen und Messergebnisse eines Testzellengebaeudes vorgestellt. (BWI)

  3. Entanglement diversion and quantum teleportation of entangled coherent states

    Institute of Scientific and Technical Information of China (English)

    Cai Xin-Hua; Guo Jie-Rong; Nie Jian-Jun; Jia Jin-Ping

    2006-01-01

    The proposals on entanglement diversion and quantum teleportation of entangled coherent states are presented.In these proposals,the entanglement between two coherent states,|α〉and |-α〉,with the same amplitude but a phase difference of π is utilized as a quantum channel.The processes of the entanglement diversion and the teleportation are achieved by using the 5050 symmetric beam splitters,the phase shifters and the photodetectors with the help of classical information.

  4. Device-independent entanglement certification of all entangled states

    OpenAIRE

    Bowles, Joseph; Šupić, Ivan; Cavalcanti, Daniel; Acín, Antonio

    2018-01-01

    We present a method to certify the entanglement of all bipartite entangled quantum states in a device-independent way. This is achieved by placing the state in a quantum network and constructing a correlation inequality based on an entanglement witness for the state. Our method is device-independent, in the sense that entanglement can be certified from the observed statistics alone, under minimal assumptions on the underlying physics. Conceptually, our results borrow ideas from the field of s...

  5. Particle size distribution as a new measuring quantity in waste water filtration; Partikelgroessenverteilung als neue Messgroesse in der Abwasserfiltration

    Energy Technology Data Exchange (ETDEWEB)

    Herwig, V.; Tiehm, A.; Neis, U. [Technische Univ. Hamburg-Harburg, Hamburg (Germany). Arbeitsbereich Abwasserwirtschaft

    1999-07-01

    The transport and distribution of anthropogenous water constituents are closely related to the behaviour of suspended solids. At municipal sewage treatment plants the elimination of solids takes place as a rule through sedimentation in sedimentation tanks. Because of more stringent cleaning requirements, a chamber filter is frequently added downstream for further elimination of suspended solids. Only through the combination of sedimentation and chamber filtration is reliable retention of solids and associated pollutants or nutrients safeguarded. This work aims to gain better understanding of the processes in the filter through a methodically new approach. This will form the basis for optimized dimensioning and more economical operation of interconnected elimination of solids through sedimentation and filtration. (orig.) [German] Der Transport und die Verteilung anthropogener Wasserinhaltsstoffe steht in engem Zusammenhang mit dem Verhalten der suspendierten Feststoffen. Die Feststoffabtrennung erfolgt in kommunalen Klaeranlagen in der Regel durch Sedimentation in der Nachklaerung. Aufgrund verschaerfter Reinigungsanforderungen wird zur weitergehenden Entfernung der suspendierten Feststoffe haeufig ein Raumfilter nachgeschaltet. Erst durch die Kombination von Sedimentation/Raumfiltration wird ein sicherer Rueckhalt der Feststoffe und assoziierter Schad- sowie Naehrstoffe erreicht. Ziel dieser Arbeit ist es, mit einem methodisch neuen Ansatz zu einem besseren Verstaendnis der Prozesse im Raumfilter zu gelangen. Dieses bildet die Grundlage fuer die optimierte Bemessung und einen oekonomischeren Betrieb der Feststoffseparation im Verbund Nachklaerung/Raumfiltration. (orig.)

  6. Haben sich die WHI-Resultate auf die Inanspruchnahme von Hormontherapie bei Frauen in der Schweiz niedergeschlagen? - Eine Auswertung der Schweizerischen Gesundheitsbefragung 2002

    Directory of Open Access Journals (Sweden)

    Baschung B

    2008-01-01

    Full Text Available Einleitung: Im Juli 2002 wurden die Daten der Women’s-Health-Initiative-Studie (WHI-Studie veröffentlicht und zeigten ein erhöhtes Risiko für Herz-Kreislauf-Krankheiten. Im gleichen Jahr wurde von Januar bis Dezember die Schweizerische Gesundheitsbefragung (SGB durchgeführt. Methoden: Wir analysierten in der SGB 2002 (19.706 durchgeführte Interviews die selbst berichteten Angaben zur gegenwärtigen Inanspruchnahme der Hormontherapie (HT in der Schweiz vor und nach der Publikation der WHI-Resultate der Frauen im Alter über 45 Jahre mit einer zusätzlichen Auswertung für die Inanspruchnahme der HT aus präventiven Gründen. Wir berechneten repräsentative Prävalenzangaben durch Gewichtung entsprechend dem Design der Stichprobenziehung. In multivariablen logistischen Regressionen wurde der Zusammenhang mit möglichen Einflussvariablen untersucht. Resultate: Die Prävalenz der HT betrug bei Befragten im Zeitraum vor der Publikation (Januar–Juni 2002 20,4 % und 23,2% bei Befragten im Zeitraum danach (August–Dezember 2002. Selbst nach Bereinigung für mögliche Einflussvariablen zeigte sich kein Zeittrend (bereinigte OR = 1,12; 95 %-Vertrauensintervall: 0,93–1,35, dies auch für die Inanspruchnahme der HT aus präventiven Gründen (bereinigte OR = 1,04; 95 %-VI: 0,83–1,29. Frauen mit höherer Bildung, höherem Einkommen und gesünderem Lebensstil hatten häufiger eine HT. Schlussfolgerungen: Unsere Annahme, dass die Publikation der WHI-Resultate die Prävalenz der HT von Frauen über 45 in der Schweiz kurzfristig beeinflusst hatte, bestätigte sich nicht. Eine kritische Aufnahme und Verarbeitung von medizinischen Informationen ist Voraussetzung für den verantwortungsvollen Umgang mit medizinischen Leistungen. Frauen müssen fähig sein, Risiken und Nutzen abzuwägen und sich eigenständig für oder gegen eine HT zu entscheiden.

  7. Rezension von: Anette Dietrich, Ljiljana Heise (Hg.: Männlichkeitskonstruktionen im Nationalsozialismus. Formen, Funktionen und Wirkungsmacht von Geschlechterkonstruktionen im Nationalsozialismus und ihre Reflexion in der pädagogischen Praxis. Frankfurt am Main u.a.

    Directory of Open Access Journals (Sweden)

    Robert Claus

    2014-12-01

    Full Text Available Die Herausgeber/-innen dieses Sammelbandes verfolgen ein deutliches Ziel: Sie wollen die Kategorie Männlichkeit zur Analyse des Nationalsozialismus sowie den von ihm begangenen Verbrechen in den Geschichtswissenschaften etablieren. Dabei markieren sie einen eklatanten Forschungsbedarf: Wie konnte dieses Terrain bis dato derart unbeachtet bleiben, wurde der Zusammenhang zwischen Männlichkeit und Gewalt andernorts doch vielfach herausgearbeitet? Um diese Lücke zu schließen, enthält der Band eine große thematische Breite, zielgenaue Fragestellungen und facettenreiche Beiträge. Allein der Versuch, das Connell’sche Konzept der ‚hegemonialen Männlichkeit‘ aus der Soziologie auf das eigene Feld zu übertragen, führt zu Schwierigkeiten.

  8. Manipulating continuous variable photonic entanglement

    International Nuclear Information System (INIS)

    Plenio, M.B.

    2005-01-01

    I will review our work on photonic entanglement in the continuous variable regime including both Gaussian and non-Gaussian states. The feasibility and efficiency of various entanglement purification protocols are discussed this context. (author)

  9. Cosmological quantum entanglement

    International Nuclear Information System (INIS)

    Martín-Martínez, Eduardo; Menicucci, Nicolas C

    2012-01-01

    We review recent literature on the connection between quantum entanglement and cosmology, with an emphasis on the context of expanding universes. We discuss recent theoretical results reporting on the production of entanglement in quantum fields due to the expansion of the underlying spacetime. We explore how these results are affected by the statistics of the field (bosonic or fermionic), the type of expansion (de Sitter or asymptotically stationary), and the coupling to spacetime curvature (conformal or minimal). We then consider the extraction of entanglement from a quantum field by coupling to local detectors and how this procedure can be used to distinguish curvature from heating by their entanglement signature. We review the role played by quantum fluctuations in the early universe in nucleating the formation of galaxies and other cosmic structures through their conversion into classical density anisotropies during and after inflation. We report on current literature attempting to account for this transition in a rigorous way and discuss the importance of entanglement and decoherence in this process. We conclude with some prospects for further theoretical and experimental research in this area. These include extensions of current theoretical efforts, possible future observational pursuits, and experimental analogues that emulate these cosmic effects in a laboratory setting. (paper)

  10. Optimization of entanglement witnesses

    Science.gov (United States)

    Lewenstein, M.; Kraus, B.; Cirac, J. I.; Horodecki, P.

    2000-11-01

    An entanglement witness (EW) is an operator that allows the detection of entangled states. We give necessary and sufficient conditions for such operators to be optimal, i.e., to detect entangled states in an optimal way. We show how to optimize general EW, and then we particularize our results to the nondecomposable ones; the latter are those that can detect positive partial transpose entangled states (PPTES's). We also present a method to systematically construct and optimize this last class of operators based on the existence of ``edge'' PPTES's, i.e., states that violate the range separability criterion [Phys. Lett. A 232, 333 (1997)] in an extreme manner. This method also permits a systematic construction of nondecomposable positive maps (PM's). Our results lead to a sufficient condition for entanglement in terms of nondecomposable EW's and PM's. Finally, we illustrate our results by constructing optimal EW acting on H=C2⊗C4. The corresponding PM's constitute examples of PM's with minimal ``qubit'' domains, or-equivalently-minimal Hermitian conjugate codomains.

  11. Multipartite entanglement in neutrino oscillations

    International Nuclear Information System (INIS)

    Blasone, Massimo; Dell'Anno, Fabio; De Siena, Silvio; Illuminati, Fabrizio

    2009-01-01

    Particle mixing is related to multi-mode entanglement of single-particle states The occupation number of both flavor eigenstates and mass eigenstates can be used to define a multiqubit space. In such a framework, flavor neutrino states can be interpreted as multipartite mode-entangled states. By using two different entanglement measures, we analyze the behavior of multipartite entanglement in the phenomenon of neutrino oscillations.

  12. Multipartite entanglement in neutrino oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Blasone, Massimo; Dell' Anno, Fabio; De Siena, Silvio; Illuminati, Fabrizio, E-mail: blasone@sa.infn.i [Dipartimento di Matematica e Informatica, Universita degli Studi di Salerno, Via Ponte don Melillo, I-84084 Fisciano (Italy)

    2009-06-01

    Particle mixing is related to multi-mode entanglement of single-particle states The occupation number of both flavor eigenstates and mass eigenstates can be used to define a multiqubit space. In such a framework, flavor neutrino states can be interpreted as multipartite mode-entangled states. By using two different entanglement measures, we analyze the behavior of multipartite entanglement in the phenomenon of neutrino oscillations.

  13. Universal entanglement transformations without communication

    International Nuclear Information System (INIS)

    Dam, Wim van; Hayden, Patrick

    2003-01-01

    We show that in the presence of finite catalysts, any pure bipartite entangled state can be converted into any other, to unlimited accuracy, without the use of any communication, quantum or classical. We call this process embezzling entanglement because it involves removing a small amount of entanglement from the catalyst in a physically unnoticeable way

  14. Quantum Statistics and Entanglement Problems

    OpenAIRE

    Trainor, L. E. H.; Lumsden, Charles J.

    2002-01-01

    Interpretations of quantum measurement theory have been plagued by two questions, one concerning the role of observer consciousness and the other the entanglement phenomenon arising from the superposition of quantum states. We emphasize here the remarkable role of quantum statistics in describing the entanglement problem correctly and discuss the relationship to issues arising from current discussions of intelligent observers in entangled, decohering quantum worlds.

  15. Deriving covariant holographic entanglement

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Xi [School of Natural Sciences, Institute for Advanced Study, Princeton, NJ 08540 (United States); Lewkowycz, Aitor [Jadwin Hall, Princeton University, Princeton, NJ 08544 (United States); Rangamani, Mukund [Center for Quantum Mathematics and Physics (QMAP), Department of Physics, University of California, Davis, CA 95616 (United States)

    2016-11-07

    We provide a gravitational argument in favour of the covariant holographic entanglement entropy proposal. In general time-dependent states, the proposal asserts that the entanglement entropy of a region in the boundary field theory is given by a quarter of the area of a bulk extremal surface in Planck units. The main element of our discussion is an implementation of an appropriate Schwinger-Keldysh contour to obtain the reduced density matrix (and its powers) of a given region, as is relevant for the replica construction. We map this contour into the bulk gravitational theory, and argue that the saddle point solutions of these replica geometries lead to a consistent prescription for computing the field theory Rényi entropies. In the limiting case where the replica index is taken to unity, a local analysis suffices to show that these saddles lead to the extremal surfaces of interest. We also comment on various properties of holographic entanglement that follow from this construction.

  16. Die Gewalt der Frauen The aggression of women

    Directory of Open Access Journals (Sweden)

    Angelika Ebrecht

    2000-07-01

    Full Text Available Anhand historischer Beispiele aus der Zeit der letzten Jahrhundertwende in Europa stellt die Autorin den Zusammenhang von Transgression, Aggression und Inversion dar. Gegen die gängige Auffassung, Gewalt sei männlich, setzt sie Selbst- und Fremdentwürfe von Frauen, die als Duellantinnen, Soldatinnen und Mörderinnen die gesellschaftlich festgelegten Grenzen der Gewalt verletzten. Sie interpretiert dies als Versuch, die Geschlechtergrenzen zu überschreiten und sich eine Subjektposition anzueignen.To explain the connection of transgression, aggression and inversion, the author presents some authentic examples from the last turn of the century in Europe. Opposing the common view of violence as a male dominion, she presents female concepts of the self and the other that are based on violence, that is, women who became duellists, soldiers and murderers. These concepts of life have the potential of transgressing the well established social boundaries between the two sexes, thus enabling the women to take on the position of a subject.

  17. Images in quantum entanglement

    Energy Technology Data Exchange (ETDEWEB)

    Bowden, G J [School of Physics and Astronomy, University of Southampton, SO17 1BJ (United Kingdom)

    2009-08-28

    A system for classifying and quantifying entanglement in spin 1/2 pure states is presented based on simple images. From the image point of view, an entangled state can be described as a linear superposition of separable object wavefunction {psi}{sub O} plus a portion of its own inverse image. Bell states can be defined in this way: {psi}= 1/{radical}2 ({psi}{sub O}{+-}{psi}{sub I} ). Using the method of images, the three-spin 1/2 system is discussed in some detail. This system can exhibit exclusive three-particle {nu}{sub 123} entanglement, two-particle entanglements {nu}{sub 12}, {nu}{sub 13}, {nu}{sub 23} and/or mixtures of all four. All four image states are orthogonal both to each other and to the object wavefunction. In general, five entanglement parameters {nu}{sub 12}, {nu}{sub 13}, {nu}{sub 23}, {nu}{sub 123} and {phi}{sub 123} are required to define the general entangled state. In addition, it is shown that there is considerable scope for encoding numbers, at least from the classical point of view but using quantum-mechanical principles. Methods are developed for their extraction. It is shown that concurrence can be used to extract even-partite, but not odd-partite information. Additional relationships are also presented which can be helpful in the decoding process. However, in general, numerical methods are mandatory. A simple roulette method for decoding is presented and discussed. But it is shown that if the encoder chooses to use transcendental numbers for the angles defining the target function ({alpha}{sub 1}, {beta}{sub 1}), etc, the method rapidly turns into the Devil's roulette, requiring finer and finer angular steps.

  18. Images in quantum entanglement

    International Nuclear Information System (INIS)

    Bowden, G J

    2009-01-01

    A system for classifying and quantifying entanglement in spin 1/2 pure states is presented based on simple images. From the image point of view, an entangled state can be described as a linear superposition of separable object wavefunction Ψ O plus a portion of its own inverse image. Bell states can be defined in this way: Ψ= 1/√2 (Ψ O ±Ψ I ). Using the method of images, the three-spin 1/2 system is discussed in some detail. This system can exhibit exclusive three-particle ν 123 entanglement, two-particle entanglements ν 12 , ν 13 , ν 23 and/or mixtures of all four. All four image states are orthogonal both to each other and to the object wavefunction. In general, five entanglement parameters ν 12 , ν 13 , ν 23 , ν 123 and φ 123 are required to define the general entangled state. In addition, it is shown that there is considerable scope for encoding numbers, at least from the classical point of view but using quantum-mechanical principles. Methods are developed for their extraction. It is shown that concurrence can be used to extract even-partite, but not odd-partite information. Additional relationships are also presented which can be helpful in the decoding process. However, in general, numerical methods are mandatory. A simple roulette method for decoding is presented and discussed. But it is shown that if the encoder chooses to use transcendental numbers for the angles defining the target function (α 1 , β 1 ), etc, the method rapidly turns into the Devil's roulette, requiring finer and finer angular steps.

  19. Multipartite entanglement and frustration

    International Nuclear Information System (INIS)

    Facchi, P; Florio, G; Pascazio, S; Marzolino, U; Parisi, G

    2010-01-01

    Some features of the global entanglement of a composed quantum system can be quantified in terms of the purity of a balanced bipartition, made up of half of its subsystems. For the given bipartition, purity can always be minimized by taking a suitable (pure) state. When many bipartitions are considered, the requirement that purity be minimal for all bipartitions can engender conflicts and frustration will arise. This unearths an interesting link between frustration and multipartite entanglement, defined as the average purity over all (balanced) bipartitions.

  20. Multipartite entanglement and frustration

    Science.gov (United States)

    Facchi, P.; Florio, G.; Marzolino, U.; Parisi, G.; Pascazio, S.

    2010-02-01

    Some features of the global entanglement of a composed quantum system can be quantified in terms of the purity of a balanced bipartition, made up of half of its subsystems. For the given bipartition, purity can always be minimized by taking a suitable (pure) state. When many bipartitions are considered, the requirement that purity be minimal for all bipartitions can engender conflicts and frustration will arise. This unearths an interesting link between frustration and multipartite entanglement, defined as the average purity over all (balanced) bipartitions.

  1. Multipartite entanglement and frustration

    Energy Technology Data Exchange (ETDEWEB)

    Facchi, P [Dipartimento di Matematica, Universita di Bari, I-70125 Bari (Italy); Florio, G; Pascazio, S [Istituto Nazionale di Fisica Nucleare, Sezione di Bari, I-70126 Bari (Italy); Marzolino, U [Dipartimento di Fisica, Universita di Trieste, and Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34014 Trieste (Italy); Parisi, G [Dipartimento di Fisica, Universita di Roma ' La Sapienza' , Piazzale Aldo Moro 2, Centre for Statistical Mechanics and Complexity (SMC), CNR-INFM, and Istituto Nazionale di Fisica Nucleare, Sezione di Roma, 00185 Roma (Italy)], E-mail: paolo.facchi@ba.infn.it

    2010-02-15

    Some features of the global entanglement of a composed quantum system can be quantified in terms of the purity of a balanced bipartition, made up of half of its subsystems. For the given bipartition, purity can always be minimized by taking a suitable (pure) state. When many bipartitions are considered, the requirement that purity be minimal for all bipartitions can engender conflicts and frustration will arise. This unearths an interesting link between frustration and multipartite entanglement, defined as the average purity over all (balanced) bipartitions.

  2. Entanglement in miscible blends

    Science.gov (United States)

    Watanabe, Hiroshi

    2010-03-01

    The entanglement length Le of polymer chains (corresponding to the entanglement molecular weight Me) is not an intrinsic material parameter but changes with the interaction with surrounding chains. For miscible blends of cis-polyisoprene (PI) and poly(tert-butyl styrene) (PtBS), changes of Le on blending was examined. It turned out that the Le averaged over the number fractions of the Kuhn segments of the components (PI and PtBS) satisfactorily describes the viscoelastic behavior of pseudo-monodisperse blends in which the terminal relaxation time is the same for PI and PtBS.

  3. Wormholes and entanglement

    International Nuclear Information System (INIS)

    John C Baez; Vicary, Jamie

    2014-01-01

    Maldacena and Susskind have proposed a correspondence between wormholes and entanglement, dubbed ER=EPR. We study this in the context of three-dimensional topological quantum field theory (TQFT), where we show that the formation of a wormhole is the same process as creating a particle–antiparticle pair. A key feature of the ER=EPR proposal is that certain apparently entangled degrees of freedom turn out to be the same. We name this phenomenon ‘fake entanglement’, and show how it arises in our TQFT model. (paper)

  4. Multi-particle entanglement via two-party entanglement

    Science.gov (United States)

    Brassard, Gilles; Mor, Tal

    2001-09-01

    Entanglement between n particles is a generalization of the entanglement between two particles, and a state is considered entangled if it cannot be written as a mixture of tensor products of the n particles' states. We present the key notion of semi-separability, used to investigate n-particle entanglement by looking at two-party entanglement between its various subsystems. We provide necessary conditions for n-particle separability (that is, sufficient conditions for n-particle entanglement). We also provide necessary and sufficient conditions in the case of pure states. By surprising examples, we show that such conditions are not sufficient for separability in the case of mixed states, suggesting entanglement of a strange type.

  5. Study of the driving processes of frontal precipitation. Final report; Untersuchung der steuernden Prozesse bei der Niederschlagsbildung an Fronten. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Gross, P.; Kraus, H.

    1998-04-01

    The mesoscale dynamic processes, which contribute to the formation of precipitation in the vicinity of fronts, are investigated using dynamically initialized fields of the EM. Cross-sections perpendicular to 12 fronts elucidate, that the ageostrophic cross-frontal circulation is the dominant dynamical feature of a front. Precipitation develops in the upward branch of this secondary circulation closely related to the humidity budget including three-dimensional advection and source terms. The dynamical mechanisms (deformation- and shear-forcing), which dominate the development of both ageostrophic cross-frontal circulation and precipitation, are of very different type. Primitive models of fronts, like the polar front theory, don`t come up with this variability of the atmospheric forcing. (orig.) [Deutsch] Die mesoskaligen dynamischen Prozesse, die in der Umgebung von Fronten zur Bildung von Niederschlag fuehren, werden mit Hilfe von dynamisch initialisierten Feldern des EM untersucht. In Querschnitten senkrecht zu insgesamt 12 Fronten kristallisiert sich die ageostrophische Querzirkulation als bedeutendstes dynamisches Element einer Front heraus. Im aufsteigenden Ast dieser Sekundaerzirkulation entsteht, in engem Zusammenhang mit dem Haushalt der spezifischen Feuchte mit seinen besonders wichtigen Advektions- und Quelltermen, Niederschlag. Die dynamische Mechanismen (Deformations- und Scherungsforcing), die zur Ausbildung der Querzirkulation fuehren, sind in hohem Masse variabel. Dieser Mannigfaltigkeit des atmosphaerischen Antriebes werden einfache Frontmodelle, wie z.B. die Polarfronttheorie, nicht gerecht. (orig.)

  6. Correcting quantum errors with entanglement.

    Science.gov (United States)

    Brun, Todd; Devetak, Igor; Hsieh, Min-Hsiu

    2006-10-20

    We show how entanglement shared between encoder and decoder can simplify the theory of quantum error correction. The entanglement-assisted quantum codes we describe do not require the dual-containing constraint necessary for standard quantum error-correcting codes, thus allowing us to "quantize" all of classical linear coding theory. In particular, efficient modern classical codes that attain the Shannon capacity can be made into entanglement-assisted quantum codes attaining the hashing bound (closely related to the quantum capacity). For systems without large amounts of shared entanglement, these codes can also be used as catalytic codes, in which a small amount of initial entanglement enables quantum communication.

  7. Entanglement in the Bogoliubov vacuum

    DEFF Research Database (Denmark)

    Poulsen, Uffe Vestergaard; Meyer, T.; Lewenstein, M.

    2005-01-01

    We analyze the entanglement properties of the Bogoliubov vacuum, which is obtained as a second-order approximation to the ground state of an interacting Bose-Einstein condensate. We work in one- and two-dimensional lattices and study the entanglement between two groups of sites as a function...... of the geometry of the configuration and the strength of the interactions. As our measure of entanglement we use the logarithmic negativity, supplemented by an algorithmic check for bound entanglement where appropiate. The short-range entanglement is found to grow approximately linearly with the group sizes...

  8. Mining in the Federal Republic of Germany 2012. Mining industries and statistics. 64th year 2013. Documentation; Der Bergbau in der Bundesrepublik Deutschland 2012. Bergwirtschaft und Statistik. 64. Jahrgang 2013. Dokumentation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-11-15

    The annual report of the series ''The mining industry in the Federal Republic of Germany - Mountain Economics and Statistics'' is published by the Federal Ministry of Economics and Technology in cooperation with the mining authorities of the federal states. It contains comprehensive data of all production facilities of mining industry in Germany and describes the position of the German industry in the context of the overall economic development. The report shows an interest in local raw materials as well as on the international raw materials economy. Moreover, the present publication provides a detailed statistics section. [German] Der Jahresbericht in der Reihe ''Der Bergbau in der Bundesrepublik Deutschland - Bergwirtschaft und Statistik'' wird vom Bundesministerium fuer Wirtschaft und Technologie in Zusammenarbeit mit den Bergbehoerden der Bundeslaender herausgegeben. Er enthaelt umfassende Daten aller Produktionsbetriebe des Bergbaus in Deutschland und beschreibt die Lage des deutschen Bergbaus im Zusammenhang mit der gesamtwirtschaftlichen Entwicklung. Der Bericht geht sowohl auf heimische Rohstoffe als auch auf die internationale Rohstoffwirtschaft ein. Darueber hinaus liefert die vorliegende Publikation einen ausfuehrlichen Statistikteil.

  9. Photon Entanglement Through Brain Tissue.

    Science.gov (United States)

    Shi, Lingyan; Galvez, Enrique J; Alfano, Robert R

    2016-12-20

    Photon entanglement, the cornerstone of quantum correlations, provides a level of coherence that is not present in classical correlations. Harnessing it by study of its passage through organic matter may offer new possibilities for medical diagnosis technique. In this work, we study the preservation of photon entanglement in polarization, created by spontaneous parametric down-conversion, after one entangled photon propagates through multiphoton-scattering brain tissue slices with different thickness. The Tangle-Entropy (TS) plots show the strong preservation of entanglement of photons propagating in brain tissue. By spatially filtering the ballistic scattering of an entangled photon, we find that its polarization entanglement is preserved and non-locally correlated with its twin in the TS plots. The degree of entanglement correlates better with structure and water content than with sample thickness.

  10. Experimental test of entangled histories

    Science.gov (United States)

    Cotler, Jordan; Duan, Lu-Ming; Hou, Pan-Yu; Wilczek, Frank; Xu, Da; Yin, Zhang-Qi; Zu, Chong

    2017-12-01

    Entangled histories arise when a system partially decoheres in such a way that its past cannot be described by a sequence of states, but rather a superposition of sequences of states. Such entangled histories have not been previously observed. We propose and demonstrate the first experimental scheme to create entangled history states of the Greenberger-Horne-Zeilinger (GHZ) type. In our experiment, the polarization states of a single photon at three different times are prepared as a GHZ entangled history state. We define a GHZ functional which attains a maximum value 1 on the ideal GHZ entangled history state and is bounded above by 1 / 16 for any three-time history state lacking tripartite entanglement. We have measured the GHZ functional on a state we have prepared experimentally, yielding a value of 0 . 656 ± 0 . 005, clearly demonstrating the contribution of entangled histories.

  11. Maja Figge, Konstanze Hanitzsch, Nadine Teuber (Hg.: Scham und Schuld. Geschlechter(subtexte der Shoah. Bielefeld: transcript Verlag 2010.

    Directory of Open Access Journals (Sweden)

    Anette Dietrich

    2011-09-01

    Full Text Available Die Autor/-innen des interdisziplinären Sammelbandes bearbeiten die innovativen Frage nach dem Zusammenhang von Scham, Schuld und Geschlecht in der deutschen Erinnerungskultur, insbesondere nach der transgenerationellen vergeschlechtlichten Weitergabe von Scham und Schuld. Die Konzeptionierung dieser Begriffe bleibt jedoch sowohl in der Einleitung als auch in einigen Aufsätzen recht vage. Der Band leistet dennoch einen wichtigen Beitrag für die Repräsentationsgeschichte des Nationalsozialismus und bietet eine aufschlussreiche Auseinandersetzung mit der Bedeutung der Kategorie Geschlecht in der Aufarbeitung des Nationalsozialismus in Deutschland.The authors of this interdisciplinary anthology discuss the innovative question about the connection between shame, guilt, and gender in the German culture of remembrance, particularly about the transgenerational gendered passing on of shame and guilt. However, the conceptualization of these terms is left rather vague both in the introduction and in some articles. Nevertheless, this anthology makes an important contribution to the history of representation of National Socialism and offers an insightful discussion of the meaning of the category gender for the reprocessing of National Socialism in Germany.

  12. Neutrino flavor entanglement

    Energy Technology Data Exchange (ETDEWEB)

    Blasone, Massimo [Dipartimento di Fisica, Università degli Studi di Salerno, Via Ponte don Melillo, I-84084 Fisciano (Italy); INFN Sezione di Napoli, Gruppo collegato di Salerno (Italy); Dell' Anno, Fabio; De Siena, Silvio; Illuminati, Fabrizio [Dipartimento di Ingegneria Industriale, Università degli Studi di Salerno, Via Ponte don Melillo, I-84084 Fisciano (Italy)

    2013-04-15

    Neutrino oscillations can be equivalently described in terms of (dynamical) entanglement of neutrino flavor modes. We review previous results derived in the context of quantum mechanics and extend them to the quantum field theory framework, were a rich structure of quantum correlations appears.

  13. Neutrino flavor entanglement

    International Nuclear Information System (INIS)

    Blasone, Massimo; Dell'Anno, Fabio; De Siena, Silvio; Illuminati, Fabrizio

    2013-01-01

    Neutrino oscillations can be equivalently described in terms of (dynamical) entanglement of neutrino flavor modes. We review previous results derived in the context of quantum mechanics and extend them to the quantum field theory framework, were a rich structure of quantum correlations appears

  14. Facets of tripartite entanglement

    Indian Academy of Sciences (India)

    Quantum mechanical correlations between results of measurments on entangled ..... It is interesting that motivation underpinning Einstein locality is not the relativistic re- quirement of no faster-than-light signalling but rather a consideration related .... of the relevant studies see, for instance, D Home, Conceptual foundations.

  15. Climate change and decline in abundance of brown trout. Is there a link? Results from Switzerland; Klimawandel und Bachforellenrueckgang. Gibt es einen Zusammenhang? Resultate aus der Schweiz

    Energy Technology Data Exchange (ETDEWEB)

    Burkhardt-Holm, Patricia [Basel Univ. (CH). Mensch-Gesellschaft-Umwelt (MGU)

    2009-04-15

    Background, aim, and scope: In response to a 60% decrease in brown trout catch between 1980 and 2000, a Swiss-wide search was initiated to investigate possible causes. The project, named 'Fischnetz' (fishing net), investigated 12 hypotheses. One of those suggested a detrimental effect of global climate change. I report here which parameters changed and what the possible consequences for native brown trout are. Materials and methods: The literature is critically analysed and results are synthesised to show the interactions between different climatic factors and their effects on fish. Results In the last 25 years, an increase in temperature by approximately 1 C was indicated in the rivers of Switzerland. This is associated with an earlier emergence of trout from the gravel. Warming results in an upward shift of the preferred thermal habitats. Furthermore, an increase in the clinical outbreak of the Proliferative Kidney Disease PKD (for which a temperature of 15 C for more than 2-4 weeks is necessary) can be recorded. The precipitation pattern changed and an intensification of high floods in winter results in higher erosion. This can in turn lead to an increased level of fine sediments which may affect health of juvenile brown trout and is assumed to reduce reproduction success. Discussion: The consequences of climate change are discussed in concert with other anthropogenic factors. Storage reservoirs, as well as water withdrawal (and return of heated water, respectively) affect temperature profiles and sediment load. Fragmentation, channelization and straightening of rivers accelerate clogging and restrain fish from upward migration and evacuation to more suitable habitats. Conclusions: With increasing temperatures a downsizing of habitats of cold-water fish species, as well as an increase of diseases which are temperature sensitive, is assumed. Recommendations and perspectives: Mitigation measures which lead to a morphological improvement of river systems, such as river widening and improvement of the connectivity between river stretches and their tributaries, as well as improving river bank vegetation, are recommended. (orig.)

  16. Survey of risks related to static magnetic fields in ultra high field MRI; Bestandsaufnahme zu Risiken durch statische Magnetfelder im Zusammenhang mit der Ultrahochfeld-MRT

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, H.E. [Max-Planck-Inst. fuer Kognitions- und Neurowissenschaften, Leipzig (Germany); Cramon, D.Y. von [Max-Planck-Inst. fuer Kognitions- und Neurowissenschaften, Leipzig (Germany); Max-Planck-Inst. fuer Neurologische Forschung, Koeln (Germany)

    2008-04-15

    In magnetic resonance imaging (MRI), substantial improvements with respect to sensitivity are expected due to the development of so-called ultra high field scanners, i.e., whole-body scanners with a magnetic field strength of 7 T or above. Users of this technology need to evaluate this benefit for potential risks since commercially available systems are not certified as a medical device for human use. This review provides a detailed survey of static field bioeffects related to the exposure of subjects being scanned, to occupational exposure, and to exposure of the general public under consideration of current standards and directives. According to present knowledge, it is not expected that exposure of human subjects to static magnetic fields of 7 T implies a specific risk of damage or disease provided that known contraindications are observed. The available database does not permit definition of exact thresholds for harmful effects. However, experience from previous application of ultra high field MRI indicates that transient phenomena, such as vertigo, nausea, metallic taste, or magnetophosphenes, are more frequently observed. In particular, movements in the field or the gradient of the fringe field seem to lead to detectable effects. Besides such observations, there is a strong demand for systematic investigation of potential interaction mechanisms related to static field exposure during MRI examinations. (orig.)

  17. Der Lerntyp macht den Unterschied – Zusammenhang von Kolbs Lerntypen mit psychischen Befunden von Medizinstudierenden im vorklinischen Studienabschnitt am Hochschulstandort Erlangen

    Directory of Open Access Journals (Sweden)

    Burger, Pascal H.

    2014-11-01

    Full Text Available [english] Theories on learning styles and types have been integral to discussions on the basics of teaching for nearly 40 years. The learning style typology of Kolb divides learners into four groups (Diverger, Assimilator, Converger and Accomodator, which differ both in terms of their learning behaviour as well as personality and preferences. We studied the sense of coherence and burnout symptoms in medical students of the preclinical semesters (1 to 4 semester at the Friedrich-Alexander University of Erlangen within the context of the observed learning styles. A total of 530 students were interviewed in winter semester 2012/13 using standardized psychometric questionnaires. Our students showed a significant correlation between the respective learning styles and expression of a sense of coherence, as well as cognitive and emotional burnout symptoms. The learning styles of the students differed significantly within these same parameters. We also demonstrated that learning styles and types not only influence study performance, but that there are also relationships to sense of coherence and psychological ailments. A more forward-looking integration of the theory of learning types in the medical education curriculum could positively influence both the performance and psychological well-being of the students.

  18. Determination of radon emission rate with regard to energetic reconstruction of buildings; Bestimmung der Radonquellstaerke im Zusammenhang mit Massnahmen zur energetischen Sanierung von Gebaeuden

    Energy Technology Data Exchange (ETDEWEB)

    Neugebauer, Thomas; Grund, A.L.; Hingmann, H.; Buermeyer, J.; Grimm, V.; Breckow, J. [Technische Hochschule Mittelhessen (THM), Giessen (Germany). Inst. fuer Medizinische Physik und Strahlenschutz (IMPS)

    2015-07-01

    In frame of a project funded by the Federal Office for Radiation Protection (BfS) the influence of meteorological and room climate parameters and energetic reconstruction on the radon concentration inside buildings has been investigated. For this purpose parameters like temperature, air pressure, relative humidity and carbon dioxide concentration have been measured. The daily and seasonal variations of the radon concentration were influenced by the behaviour of the residents. A parameter less influenced by this behaviour is the radon emission rate. Complementary to the above mentioned project the method of determination of the radon emission rate has been developed in frame of a project funded by the Ministry of the Environment of Hesse (HMUKLV). With the improved method, it is possible to determine the radon emission rate on a continuous base. Therefore both, the radon concentration and the air exchange rate of a building have to be determined. For the verification of the method simulations and measurements have been performed. Additionally meteorological parameters have been recorded in order to evaluate possible influences on the radon emission rate.

  19. Multipartite entangled quantum states: Transformation, Entanglement monotones and Application

    Science.gov (United States)

    Cui, Wei

    Entanglement is one of the fundamental features of quantum information science. Though bipartite entanglement has been analyzed thoroughly in theory and shown to be an important resource in quantum computation and communication protocols, the theory of entanglement shared between more than two parties, which is called multipartite entanglement, is still not complete. Specifically, the classification of multipartite entanglement and the transformation property between different multipartite states by local operators and classical communications (LOCC) are two fundamental questions in the theory of multipartite entanglement. In this thesis, we present results related to the LOCC transformation between multipartite entangled states. Firstly, we investigate the bounds on the LOCC transformation probability between multipartite states, especially the GHZ class states. By analyzing the involvement of 3-tangle and other entanglement measures under weak two-outcome measurement, we derive explicit upper and lower bound on the transformation probability between GHZ class states. After that, we also analyze the transformation between N-party W type states, which is a special class of multipartite entangled states that has an explicit unique expression and a set of analytical entanglement monotones. We present a necessary and sufficient condition for a known upper bound of transformation probability between two N-party W type states to be achieved. We also further investigate a novel entanglement transformation protocol, the random distillation, which transforms multipartite entanglement into bipartite entanglement ii shared by a non-deterministic pair of parties. We find upper bounds for the random distillation protocol for general N-party W type states and find the condition for the upper bounds to be achieved. What is surprising is that the upper bounds correspond to entanglement monotones that can be increased by Separable Operators (SEP), which gives the first set of

  20. Editorial: Qualitative Forschung in der Medienpädagogik

    Directory of Open Access Journals (Sweden)

    Horst Niesyto

    2008-01-01

    Orientierungsmuster herausgearbeitet, die für Jugendliche unterschiedliche Partizipationsmöglichkeiten im Umgang mit Medien eröffnen. Die Analysen verstehen sich als ein Beitrag zur bislang wenig entwickelten medienpädagogischen Professionsforschung. Der Beitrag von Ulrike Wagner und Helga Theunert über «Konvergenzbezogene Medienaneignung in Kindheit und Jugend» stellt das Konzept der konvergenzbezogenen Medienaneignung vor und gibt einen Überblick zu den bisherigen Grundlagenstudien, die das JFF (Institut für Medienpädagogik in Forschung und Praxis im Zeitraum von 2001 bis 2007 durchführte. Der Beitrag konzentriert sich dabei auf die Reflexion von Forschungsperspektiven, die dem vernetzten Medienhandeln von Kindern und Jugendlichen unter inhaltlichen und methodologischen Aspekten gerecht werden. Am Beispiel der dritten Konvergenzstudie werden die methodischen Zugänge bei der Erhebung (Kontaktinterview und Intensivinterview mit Narrationsanreizen, Erfassung von Kontextinformationen sowie bei der Auswertung vorgestellt (Herausarbeitung typischer Muster der konvergenzbezogenen Medienaneignung durch Einzelfallstudien. Als Leitlinien für ihr forschungsmethodisches Vorgehen heben die Autorinnen «Kontextorientierung», «sinnliche und symbolische Dimensionen» sowie «Exemplarität» des Medienhandelns hervor. Mehrere Beiträge gehen auf die Frage ein, welche besonderen Bedingungen mit einer Erforschung des Internets verknüpft sind. Winfried Marotzki betont in seinem Beitrag den kulturellen Charakter des Internets und stellt im Anschluss daran die Charakteristik jener Trends dar, welche mit dem Begriff des Web 2.0 verbunden sind. Methodisch favorisiert er zur Erforschung dieses neuen Raumes diskursanalytische Verfahren in der Tradition wissenssoziologischen Denkens. Diskurse sieht er in diesem Zusammenhang als Artikulation von Erfahrungsräumen innerhalb eines multimodalen Ausdruckskontinuums. Martina Schuegraf stellt in ihrem Beitrag «Das Surfgramm als grafische

  1. Zur Materialfrage in der Implantatchirurgie des Deszensus: Vergleich zwischen Polypropylenvlies und dermaler porciner azellulärer Kollagenmatrix unter Berücksichtigung der Erfahrungen nach 7 Jahren Anwendung von Implantaten

    Directory of Open Access Journals (Sweden)

    Fischer A

    2004-01-01

    Full Text Available Ziel der Studie: Die Studie beschreibt Verwendung, Effektivität und Nebenwirkungen zwei verschiedener Implantate, die in der Senkungschirurgie verwendet werden und stellen die Ergebnisse in einen Zusammenhang mit den Erfahrungen mit anderen Implantaten seitens der Autoren und in der Literatur. Material und Methode: 180 Patientinnen mit verschiedenen Formen von Genitalprolaps werden mit Biomesh(R behandelt, 185 Patientinnen mit Pelvicol(R in der Zeit von Juli 2000 bis Dezember 2002. Die Ergebnisse werden verglichen. Ergebnisse: Die Verwendung von Implantaten ist häufig erforderlich, vor allen Dingen in Fällen eines stark zerstörten Beckenbodensystems oder bei Rezidiven. Die Verwendung von Netz-Implantaten in der Senkungschirurgie ist sicher, solange eine vernünftige Implantatstruktur zugrunde liegt. Beide in dieser Studie untersuchten Implantate erfüllen dies zufriedenstellend. Rezidiv- und Senkungszustände der benachbarten Kompartimente müssen getrennt ausgewertet werden, um eine Verwechslung zwischen einem schlechten Therapieergebnis (obwohl es eigentlich gut ist und Strukturschwächen in den (noch nicht behandelten Kompartimenten nicht in einem Topf zu werfen. Die Notwendigkeit einer Explantation, das Ausbilden von Abszessen oder die Abstoßungsreaktion wurden nur gesehen, wenn multifilamente mikroporöse Bänder oder entsprechend strukturiertes Nahtmaterial zur gleichen Zeit eingesetzt worden sind, oder wenn Blutergußbildung nicht durch subtile Hämostase während des Eingriffs unterdrückt werden konnte. Schlußfolgerung: Beide Materialien (Biomesh(R und Pelvicol(R liefern in der Verwendung bei implantatunterstützter Deszensus-Chirurgie gute Ergebnisse, gleich, wo sie auch eingesetzt werden. Es gibt keine signifikanten Unterschiede in der Effektivität oder in der Nebenwirkungsrate. Es bedarf nun der größer angelegten multizentrischen Studien, um alloplastisch unterstützte rekonstruktive Beckenbodenchirurgie nicht nur in den

  2. Probabilistic Teleportation of the Three-Particle Entangled State viaEntanglement Swapping

    Institute of Scientific and Technical Information of China (English)

    路洪

    2001-01-01

    A scheme of teleportation of a three-particle entangled state via entanglement swapping is proposed. It is shown that if a two-particle entangled state and a three-particle entangled state (both are not maximum entangled states) are used as quantum channels, probabilistic teleportation of the three-particle entangled state can be realized.

  3. Entanglement reactivation in separable environments

    International Nuclear Information System (INIS)

    Pirandola, Stefano

    2013-01-01

    Combining two entanglement-breaking channels into a correlated-noise environment restores the distribution of entanglement. Surprisingly, this reactivation can be induced by the injection of separable correlations from the composite environment. In any dimension (finite or infinite), we can construct classically correlated ‘twirling’ environments which are entanglement-breaking in the transmission of single systems but entanglement-preserving when two systems are transmitted. Here entanglement is simply preserved by the existence of decoherence-free subspaces. Remarkably, even when such subspaces do not exist, a fraction of the input entanglement can still be distributed. This is found in separable Gaussian environments, where distillable entanglement is able to survive the two-mode transmission, despite being broken in any single-mode transmission by the strong thermal noise. In the Gaussian setting, entanglement restoration is a threshold process, occurring only after a critical amount of correlations has been injected. Such findings suggest new perspectives for distributing entanglement in realistic environments with extreme decoherence, identifying separable correlations and classical memory effects as physical resources for ‘breaking entanglement-breaking’. (paper)

  4. Braiding transformation, entanglement swapping, and Berry phase in entanglement space

    International Nuclear Information System (INIS)

    Chen Jingling; Ge Molin; Xue Kang

    2007-01-01

    We show that braiding transformation is a natural approach to describe quantum entanglement by using the unitary braiding operators to realize entanglement swapping and generate the Greenberger-Horne-Zeilinger states as well as the linear cluster states. A Hamiltonian is constructed from the unitary R i,i+1 (θ,φ) matrix, where φ=ωt is time-dependent while θ is time-independent. This in turn allows us to investigate the Berry phase in the entanglement space

  5. The entanglement purification for entangled multi-particle states

    CERN Document Server

    Ye, Liu; Guo Guang Can

    2002-01-01

    We present two purification schemes for nonmaximally entangled states. We first show that two parties, Alice and Bob, start with shared less-entangled three-particle states to probabilistically produce a three-particle Greenberger-Horne-Zeilinger state by Bell state measurements and positive operator valued measure (POVM) or a unitary transformation. Then, by a straightforward generalization of the schemes, the purification of a multi-particle entangled state can be realized. 25 Refs. --- 35 --- AN

  6. Entanglement between two interacting CFTs and generalized holographic entanglement entropy

    International Nuclear Information System (INIS)

    Mollabashi, Ali; Shiba, Noburo; Takayanagi, Tadashi

    2014-01-01

    In this paper we discuss behaviors of entanglement entropy between two interacting CFTs and its holographic interpretation using the AdS/CFT correspondence. We explicitly perform analytical calculations of entanglement entropy between two free scalar field theories which are interacting with each other in both static and time-dependent ways. We also conjecture a holographic calculation of entanglement entropy between two interacting N=4 super Yang-Mills theories by introducing a minimal surface in the S 5 direction, instead of the AdS 5 direction. This offers a possible generalization of holographic entanglement entropy

  7. Entanglement and quantum teleportation via decohered tripartite entangled states

    Energy Technology Data Exchange (ETDEWEB)

    Metwally, N., E-mail: nmohamed31@gmail.com

    2014-12-15

    The entanglement behavior of two classes of multi-qubit system, GHZ and GHZ like states passing through a generalized amplitude damping channel is discussed. Despite this channel causes degradation of the entangled properties and consequently their abilities to perform quantum teleportation, one can always improve the lower values of the entanglement and the fidelity of the teleported state by controlling on Bell measurements, analyzer angle and channel’s strength. Using GHZ-like state within a generalized amplitude damping channel is much better than using the normal GHZ-state, where the decay rate of entanglement and the fidelity of the teleported states are smaller than those depicted for GHZ state.

  8. Ranking of CT in persistent vertigo after implantation of stapes prostheses; Stellenwert der Computertomographie bei persistierenden Gleichgewichtsstoerungen nach dem Einsatz von Stapesplastiken

    Energy Technology Data Exchange (ETDEWEB)

    Koesling, S. [Leipzig Univ. (Germany). Klinik fuer Diagnostische Radiologie; Woldag, K. [Leipzig Univ. (Germany). Klinik und Poliklinik fuer Hals-Nasen-Ohren-Krankheiten; Meister, E.F. [Leipzig Univ. (Germany). Klinik und Poliklinik fuer Hals-Nasen-Ohren-Krankheiten; Reschke, I. [Leipzig Univ. (Germany). Klinik fuer Diagnostische Radiologie; Schulz, H.G. [Leipzig Univ. (Germany). Klinik fuer Diagnostische Radiologie

    1995-01-01

    10 of 150 patients had persistent vertigo after implanation of stapes prostheses. These patients were evaluated by high resolution CT in the axial and coronal plane. Scans showed in all cases findings which related to the symptoms. The CT findings were proved intraoperatively in 9 cases. A new indirect sign of a perilymphatic fistula is described in form of an air bulla at the end of the prosthesis. Retympanotomy could be planned better with the help of HR-CT. (orig.) [Deutsch] Von 150 Patienten zeigten 10 nach dem Einsatz einer Stapesprothese eine persistierende vestibulaere Symptomatik. Mittels der hochaufloesenden Felsenbein-CT in axialer und koronarer Schnittfuehrung konnten in allen Faellen in Symptomatik erklaerende Befunde erhoben werden. Eine operative Bestaetigung erfolgte in 9 Faellen. Als bisher in der Literatur in diesem Zusammenhang nicht beschriebenes, indirektes Zeichen einer Perilymphfistel wurde eine kleine Luftblase am Prothesenende nachgewiesen. Die HR-CT hat sich als wesentliche Erleichterung bei der Planung einer Retympanotomie erwiesen. (orig.)

  9. Studien zur Messung von Rekonstruktionseffizienz und Untergrund der $\\tau$-Lepton-Identifikation im Zerfall $Z\\to \\tau \\tau$ beim ATLAS-Experiment aus Daten

    CERN Document Server

    Johnert, Sebastian

    2008-01-01

    In dieser Diplomarbeit werden zwei Methoden vorgestellt, mit denen τ -Leptonen in den zuk ̈nf- u tigen Daten des ATLAS-Experiments untersucht werden sollen. Den ersten Teil bildet die Be- stimmung von Missidentifikationsraten von Jets aus QCD-2-Jet-Ereignissen als τ -Leptonen. Der zweite Teil ist die Entwicklung einer Methode zur Bestimmung der τ -Rekonstruktions- und -Identifikationseffizienz relativ zur μ-Effizienz. In diesem Zusammenhang werden invariante Massen aus Z → ll-Ereignissen bestimmt, die Massen aus Z → τ τ -Ereignissen mit denen aus Z → ee und Z → μμ verglichen, τ -Effizienzen gemittelt uber alle Bereiche und in verschiedenen ̈ o η-Bereichen berechnet sowie eine M ̈glichkeit zur Bestimmung von τ -Effizienzen in unterschied- lichen Transversalimpulsbereichen vorgestellt. Des Weiteren wird eine verbesserte Absch ̈tzung a des QCD-Untergrunds vorgenommen und das Verhalten der τ -Effizienz unter Ber ̈cksichtigung u des Triggers untersucht.

  10. Entangled network and quantum communication

    Energy Technology Data Exchange (ETDEWEB)

    Metwally, Nasser, E-mail: Nmetwally@gmail.com [Math. Dept., Faculty of Science, South Valley University, Aswan (Egypt); Math. Dept., College of Science, University of Bahrain, P.O. Box 32038 (Bahrain)

    2011-11-21

    A theoretical scheme is introduced to generate entangled network via Dzyaloshinskii–Moriya (DM) interaction. The dynamics of entanglement between different nodes, which is generated by direct or indirect interaction, is investigated. It is shown that, the direction of (DM) interaction and the locations of the nodes have a sensational effect on the degree of entanglement. The minimum entanglement generated between all the nodes is quantified. The upper and lower bounds of the entanglement depend on the direction of DM interaction, and the repetition of the behavior depends on the strength of DM. The generated entangled nodes are used as quantum channel to perform quantum teleportation, where it is shown that the fidelity of teleporting unknown information between the network members depends on the locations of the members.

  11. Quantum entanglement via nilpotent polynomials

    International Nuclear Information System (INIS)

    Mandilara, Aikaterini; Akulin, Vladimir M.; Smilga, Andrei V.; Viola, Lorenza

    2006-01-01

    We propose a general method for introducing extensive characteristics of quantum entanglement. The method relies on polynomials of nilpotent raising operators that create entangled states acting on a reference vacuum state. By introducing the notion of tanglemeter, the logarithm of the state vector represented in a special canonical form and expressed via polynomials of nilpotent variables, we show how this description provides a simple criterion for entanglement as well as a universal method for constructing the invariants characterizing entanglement. We compare the existing measures and classes of entanglement with those emerging from our approach. We derive the equation of motion for the tanglemeter and, in representative examples of up to four-qubit systems, show how the known classes appear in a natural way within our framework. We extend our approach to qutrits and higher-dimensional systems, and make contact with the recently introduced idea of generalized entanglement. Possible future developments and applications of the method are discussed

  12. Landschaftsbereiche der Provinz Latina

    Directory of Open Access Journals (Sweden)

    Luigi Piemontese

    2012-08-01

    Full Text Available Das Konzept der Landschaft setz sich zusammen aus verschiedenen Bezugspunkten und Interpretationen, je nach dem Blickpunkt, und ihre Wahnehrung veraendert sich je nach der verschiedenartigen Brille mit der man sie sieht. Der Artikel, geht von der Definition der Landschaft aus, wie sie in der Eurpaischen Konvention zitiert ist :“ Ein Teil des Landes, wie es von seinen Volk gesehen ist, dessen Charakter geformt ist aus naturlichen und menschlichen Faktoren und deren Wechselverhaeltnis”. Er wird fortgefuehrt mit der Identifikation der Landschaftsbereiche der Provinz Latina, die angesehn werden sollen als klimatisch, litologisch und morphologisch aenliche Landschaftsportionen, in denen erstens die Merkmale der Flora und Fauna klar werden und an zweiter Stelle, durch den Gebrauch des Territoriums und die Veraendungen mit denen er es gezeichnet hat, das Tun des Menschen. Die Methodik ruht teilweise auf der Klassifizierung des Territoriums, ausgearbeitet von C.Blasio und dem Konkretfall angeglichen.

  13. Der Mythos Konzernzentrale

    OpenAIRE

    Menz, Markus; Kunisch, Sven; Collis, David J.

    2015-01-01

    Sie werden als Zeichen von Leistung und Erfolg bewundert, aber auch als Ort der Machtkämpfe und Bürokratie misstrauisch beäugt. Haben Konzernzentralen in Zeiten der digitalen Vernetzung und der Globalisierung noch einen Sinn?

  14. Hyperspherical entanglement entropy

    International Nuclear Information System (INIS)

    Dowker, J S

    2010-01-01

    The coefficient of the log term in the entanglement entropy associated with hyperspherical surfaces in flat spacetime is shown to equal the conformal anomaly by conformally transforming Euclideanized spacetime to a sphere and using already existing formulae for the relevant heat-kernel coefficients after cyclic factoring. The result follows from the fact that the conformal anomaly on this lune has an extremum at the ordinary sphere limit. A proof is given. Agreement with a recent evaluation of the coefficient is found.

  15. Hyperspherical entanglement entropy

    Energy Technology Data Exchange (ETDEWEB)

    Dowker, J S, E-mail: dowker@man.ac.u [Theory Group, School of Physics and Astronomy, University of Manchester, Manchester (United Kingdom)

    2010-11-05

    The coefficient of the log term in the entanglement entropy associated with hyperspherical surfaces in flat spacetime is shown to equal the conformal anomaly by conformally transforming Euclideanized spacetime to a sphere and using already existing formulae for the relevant heat-kernel coefficients after cyclic factoring. The result follows from the fact that the conformal anomaly on this lune has an extremum at the ordinary sphere limit. A proof is given. Agreement with a recent evaluation of the coefficient is found.

  16. Inter-Universal Quantum Entanglement

    Science.gov (United States)

    Robles-Pérez, S. J.; González-Díaz, P. F.

    2015-01-01

    The boundary conditions to be imposed on the quantum state of the whole multiverse could be such that the universes would be created in entangled pairs. Then, interuniversal entanglement would provide us with a vacuum energy for each single universe that might be fitted with observational data, making testable not only the multiverse proposal but also the boundary conditions of the multiverse. Furthermore, the second law of the entanglement thermodynamics would enhance the expansion of the single universes.

  17. Global entanglement in multiparticle systems

    International Nuclear Information System (INIS)

    Meyer, David A.; Wallach, Nolan R.

    2002-01-01

    We define a polynomial measure of multiparticle entanglement which is scalable, i.e., which applies to any number of spin-(1/2) particles. By evaluating it for three particle states, for eigenstates of the one dimensional Heisenberg antiferromagnet and on quantum error correcting code subspaces, we illustrate the extent to which it quantifies global entanglement. We also apply it to track the evolution of entanglement during a quantum computation

  18. Gravity as Quantum Entanglement Force

    OpenAIRE

    Lee, Jae-Weon; Kim, Hyeong-Chan; Lee, Jungjai

    2010-01-01

    We conjecture that the total quantum entanglement of matter and vacuum in the universe tends to increase with time, like entropy, and that an effective force is associated with this tendency. We also suggest that gravity and dark energy are types of quantum entanglement forces, similar to Verlinde's entropic force, and give holographic dark energy with an equation of state comparable to current observational data. This connection between quantum entanglement and gravity could give some new in...

  19. Fallbericht: Seltene Raumforderungen der Leiste in der klinischen Erscheinung inguinaler Hernien: eine seminomatöse Lymphknotenmetastase und ein Liposarkom des Samenstranges

    Directory of Open Access Journals (Sweden)

    Burger M

    2005-01-01

    Full Text Available Einleitung: Wir berichten über eine seminomatöse inguinale Lymphknotenmetastase und ein Liposarkom des Samenstranges, die sich klinisch als eine inguinale Hernie präsentierten. Kasuistik: Fall 1: Ein 53jähriger Patient wurde unter der Annahme einer inguinalen Hernie links in einer chirurgischen Abteilung operiert. Es fand sich eine Raumforderung, welche in der Schnellschnittuntersuchung den Befund einer seminomatösen Lymphknotenmetastase ergab. In der folgenden Abklärung ergab sich ein linksseitiges pT2-Seminom. Anamnestisch wurde vor 26 Jahren eine inguinale Varikozelektomie links vorgenommen. Fall 2: Ein 61jähriger Patient stellte sich mit einer schmerzlosen Raumforderung der rechten Leiste vor, die klinisch als inguinale Hernie imponierte und seit drei Jahren größenprogredient war. Die Ultraschall- und MRT-Befunde wurden als eine inguinale Hernie mit einem Peritonealfett enthaltenden Bruchsack gedeutet. Intraoperativ fand sich ein Liposarkom des Samenstranges. Schlußfolgerung: Trotz der Häufigkeit inguinaler Herniotomien sind überraschende maligne Raumforderungen selten. Man sollte diese Möglichkeit aber bei transskrotalen Eingriffen in der Anamnese und bei nicht eindeutig einzuordnenden Befunden differentialdiagnostisch bedenken. Inguinale Lymphknotenmetastasen testikulärer Neoplasien sind selten, in der Literatur ist ein eindeutiger Zusammenhang mit Eingriffen im Skrotal- und Leistenbereich beschrieben. Die klinische Erscheinung einer solchen als Leistenhernie ist bisher noch nicht beschrieben worden. Liposarkome des Samenstranges sind ebenfalls selten. Therapeutisch sollte eine radikale chirurgische Exzision und in Fällen unklarer Absetzungsränder eine Radiatio erfolgen. Lokalrezidive treten häufig und eventuell auch spät auf.

  20. Der Zustandsbegriff in der Systemtheorie

    OpenAIRE

    Wendt, Siegfried

    1999-01-01

    Für die Systemtheorie ist der Begriff Zustand ein sehr zentraler Begriff. Das Wort "Zustand" wird um-gangssprachlich recht häufig verwendet, aber wenn man die Leute fragen würde, was sie denn meinen,wenn sie das Wort Zustand benützen, dann würde man sicher nicht die präzise Definition bekommen,die man für die Systemtheorie braucht.

  1. UBER DEN BEITRITT DER PLURIMODALITÄT DES VERSTEHENS DER NICHTEUROPÄISCHEN TRADITION. DISCOURS ÜBER DISCOURS. (PROBLEMATISIERUNG INITIERT MIT DEM WERK "CARSTVO ZNAKOVA" VON ROLAND BARTHES, AUGUST CESAREC, ZAGREB 1989

    Directory of Open Access Journals (Sweden)

    Jadran Zalokar

    1990-01-01

    Full Text Available In diesem Text problematisiert der Verfasser manche grundsätzlicke Fragen des Verstehens nichteuropäischen Traditionen im Ganzen. Dabei analysiert er das Werk von Roland Barthes in Zusammenhang des Verstehens der Beziehung textuallen im Gegensatz zum geistlichen Tradition Japans, gleichzeitig auf die methodologisch wichtige Frage hinweisend. Alles enken und "Schreiben" darüber ist in nuce zweifelhaft. Das Denken des planetaren Polilogen als Multiloge verlangt einen strengen wissenschaftlichen Beitritt, aber auch einen metawissenschaftlichen und metaphilosphischen Einblick in das geistliche Wesen nichteuropäischen Tradition, weil es gleichmäßige Beachtung verschiedensten geistlichen Erfahrungen und Eingenartigkeiten des geistlichen Lebens aller Traditionen nötig ist und nurwissenschaftlicher und nurphilosophischer Beitritt ist nicht genügend.

  2. Experimental Entanglement Distribution by Separable States

    Science.gov (United States)

    Vollmer, Christina E.; Schulze, Daniela; Eberle, Tobias; Händchen, Vitus; Fiurášek, Jaromír; Schnabel, Roman

    2013-12-01

    Distribution of entanglement between macroscopically separated parties is crucial for future quantum information networks. Surprisingly, it has been theoretically shown that two distant systems can be entangled by sending a third system that is not entangled with either of them. Here, we experimentally distribute entanglement and successfully prove that our transmitted light beam is indeed not entangled with the parties’ local systems. Our work demonstrates an unexpected variant of entanglement distribution and improves the understanding necessary to engineer multipartite quantum networks.

  3. Error exponents for entanglement concentration

    International Nuclear Information System (INIS)

    Hayashi, Masahito; Koashi, Masato; Matsumoto, Keiji; Morikoshi, Fumiaki; Winter, Andreas

    2003-01-01

    Consider entanglement concentration schemes that convert n identical copies of a pure state into a maximally entangled state of a desired size with success probability being close to one in the asymptotic limit. We give the distillable entanglement, the number of Bell pairs distilled per copy, as a function of an error exponent, which represents the rate of decrease in failure probability as n tends to infinity. The formula fills the gap between the least upper bound of distillable entanglement in probabilistic concentration, which is the well-known entropy of entanglement, and the maximum attained in deterministic concentration. The method of types in information theory enables the detailed analysis of the distillable entanglement in terms of the error rate. In addition to the probabilistic argument, we consider another type of entanglement concentration scheme, where the initial state is deterministically transformed into a (possibly mixed) final state whose fidelity to a maximally entangled state of a desired size converges to one in the asymptotic limit. We show that the same formula as in the probabilistic argument is valid for the argument on fidelity by replacing the success probability with the fidelity. Furthermore, we also discuss entanglement yield when optimal success probability or optimal fidelity converges to zero in the asymptotic limit (strong converse), and give the explicit formulae for those cases

  4. Entanglement in a parametric converter

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Su-Yong; Qamar, Shahid; Lee, Hai-Woong; Zubairy, M Suhail [Center for Quantum Physics, COMSATS Institute of Information Technology, Islamabad (Pakistan)], E-mail: shahid_qamar@pieas.edu.pk, E-mail: zubairy@physics.tamu.edu

    2008-07-28

    In this paper, we consider a parametric converter as a source of entangled radiation. We examine recently derived conditions (Hillery and Zubairy 2006 Phys. Rev. Lett. 96 050503, Duan et al 2000 Phys. Rev. Lett. 84 2722) for determining when the two output modes in a parametric converter are entangled. We show that for different initial field states, the two criteria give different conditions that ensure that the output states are entangled. We also present an input-output calculation for the entanglement of the output field.

  5. Multi-Photon Entanglement and Quantum Teleportation

    National Research Council Canada - National Science Library

    Shih, Yanhua

    1999-01-01

    The project 'Multi-Photon Entanglement and Quantum Teleportation' concerns a series of experimental and theoretical investigations on multi-photon entangled states and the applications, for example...

  6. Zur Sozialgeschichte der Gerechtigkeit in der Neuzeit

    Directory of Open Access Journals (Sweden)

    Koller Peter

    2014-12-01

    Full Text Available Der Beitrag verfolgt das Ziel, die Entwicklung der Idee der Gerechtigkeit in der Neuzeit im Kontext des sozialen Wandels zu erhellen. Zu diesem Zweck wird nach einer einleitenden Erörterung des dieser Idee zugrundeliegenden Gerechtigkeitsbegriffs (1 zuerst das Projekt einer vertragstheoretischen Begründung einer gerechten staatlichen Ordnung in der frühen Neuzeit vor dem Hintergrund des Herausbildung des modernen Staates behandelt (2. Im Anschluss werden die theoretischen Leitideen und gesellschaftlichen Triebkräfte des Kampfes um bürgerliche Freiheit und demokratische Teilhabe beleuchtet (3, wovon ausgehend dann die Entstehung der heute vorherrschenden Vorstellung von sozialer Gerechtigkeit einer näheren Betrachtung unterzogen wird (4. Der Beitrag endet mit einigen Bemerkungen über die Gerechtigkeitsprobleme der Gegenwart und die künftigen Herausforderungen im Kampf um Gerechtigkeit (5.

  7. Quantitative CT assessment of proximal femoral bone density. An experimental study concerning its correlation to breaking load for femoral neck fractures; Quantitative CT des proximalen Femurs. Experimentelle Untersuchungen zur Korrelation mit der Bruchlast bei Schenkelhalsfrakturen

    Energy Technology Data Exchange (ETDEWEB)

    Buitrago-Tellez, C.H.; Schulze, C.; Gufler, H.; Langer, M. [Abt. Roentgendiagnostik, Radiologische Universitaetsklinik, Albert-Ludwigs-Univ. Freiburg (Germany); Bonnaire, F.; Hoenninger, A.; Kuner, E. [Abt. Unfallchirurgie, Chirurgische Universitaetsklinik, Albert-Ludwigs-Univ. Freiburg (Germany)

    1997-12-01

    Purpose: In an experimental study, the correlation between the trabecular bone density of the different regions of the proximal femur and the fracture load in the setting of femoral neck fractures was examined. Methods: The bone mineral density 41 random proximal human femora was estimated by single-energy quanitative CT (SE-QCT). The trabecular bone density was measured at the greatest possible extracortical volume at midcapital, midneck and intertrochanteric level and in the 1 cm{sup 3} volumes of the centres of these regions in a standardised 10 mm thick slice in the middle of the femoral neck axis (in mg/ml Ca-hydroxyl apatite). The proximal femora were then isolated and mounted on a compression/bending device under two-legged stand conditions and loaded up to the point when a femoral neck fracture occurred. Results: Statistical analysis revealed a linear correlation between the trabecular bone density and the fracture load for the greater regions, with the highest value in the maximal area of the head (coefficient factor r=0.76). Conclusion: According to our data, the measurement of the trabecular bone by SE-QCT at the femoral head is a more confident adjunct than the neck or trochanteric area to predict a femoral neck fracture. (orig.) [Deutsch] Ziel: In einer experimentellen Versuchsserie wurde der Zusammenhang zwischen der Knochendichte an verschiedenen Lokalisationen des proximalen Femurs und der maximalen Last bei der Entstehung von Schenkelhalsfrakturen (Bruchlast) untersucht. Methode: An 41 frisch entnommenen proximalen Leichenfemora wurde die trabekulaere Knochendichte mit Hilfe der Ein-Energie Quantitativen Computertomographie (SE-QCT) bei einer Schichtdicke von 10 mm in der Mitte der Schenkelhalsachse bestimmt. Erfasst wurden die maximale extrakortikale, zylinderfoermige Messregion im Hueftkopf, Schenkelhals und der Intertrochantaerregion sowie das 1 cm{sup 3} umfassende Zentrum dieser Regionen. Die Praeparate wurden unter Zweibeinstandbedingungen

  8. Umsetzung der Unternehmensstrategie mit der Balanced Scorecard

    Science.gov (United States)

    Crespo, Isabel; Bergmann, Lars; Portmann, Stefan; Lacker, Thomas; Lacker, Michael; Fleischmann, Jürgen; Kozó, Hans

    Die Balanced Scorecard (BSC) ist ein Ansatz zum strategischen Management, der neben der Ausrichtung des Unternehmens auf finanzielle Zielwerte ebenso großes Gewicht auf so genannte weiche Faktoren legt, die den wirtschaftlichen Erfolg eines Unternehmens erst ermöglichen. Das entscheidende Merkmal der Balanced Scorecard ist dabei, dass sie ein ausgewogenes System strategischer Ziele herstellt, welches das Unternehmen hinsichtlich der vier Perspektiven Finanzen, Kunden, interne Prozesse und Mitarbeiter und Potenziale strategisch ausrichtet (Kaplan u. Norton 1997).

  9. Partial recovery of entanglement in bipartite-entanglement transformations

    International Nuclear Information System (INIS)

    Bandyopadhyay, Somshubhro; Roychowdhury, Vwani; Vatan, Farrokh

    2002-01-01

    Any deterministic bipartite-entanglement transformation involving finite copies of pure states and carried out using local operations and classical communication (LOCC) results in a net loss of entanglement. We show that for almost all such transformations, partial recovery of lost entanglement is achievable by using 2x2 auxiliary entangled states, no matter how large the dimensions of the parent states are. For the rest of the special cases of deterministic LOCC transformations, we show that the dimension of the auxiliary entangled state depends on the presence of equalities in the majorization relations of the parent states. We show that genuine recovery is still possible using auxiliary states in dimensions less than that of the parent states for all patterns of majorization relations except only one special case

  10. Statistical mechanics of multipartite entanglement

    Science.gov (United States)

    Facchi, P.; Florio, G.; Marzolino, U.; Parisi, G.; Pascazio, S.

    2009-02-01

    We characterize the multipartite entanglement of a system of n qubits in terms of the distribution function of the bipartite purity over all balanced bipartitions. We search for those (maximally multipartite entangled) states whose purity is minimum for all bipartitions and recast this optimization problem into a problem of statistical mechanics.

  11. Statistical mechanics of multipartite entanglement

    Energy Technology Data Exchange (ETDEWEB)

    Facchi, P [Dipartimento di Matematica, Universita di Bari, I-70125 Bari (Italy); Florio, G; Pascazio, S [Istituto Nazionale di Fisica Nucleare, Sezione di Bari, I-70126 Bari (Italy); Marzolino, U [Dipartimento di Fisica Teorica, Universita di Trieste, Strada Costiera 11, 34014 Trieste (Italy); Parisi, G [Dipartimento di Fisica, Universita di Roma ' La Sapienza' , Piazzale Aldo Moro 2, 00185 Roma, Italy, Centre for Statistical Mechanics and Complexity (SMC), CNR-INFM, 00185 Roma (Italy)

    2009-02-06

    We characterize the multipartite entanglement of a system of n qubits in terms of the distribution function of the bipartite purity over all balanced bipartitions. We search for those (maximally multipartite entangled) states whose purity is minimum for all bipartitions and recast this optimization problem into a problem of statistical mechanics.

  12. Statistical mechanics of multipartite entanglement

    International Nuclear Information System (INIS)

    Facchi, P; Florio, G; Pascazio, S; Marzolino, U; Parisi, G

    2009-01-01

    We characterize the multipartite entanglement of a system of n qubits in terms of the distribution function of the bipartite purity over all balanced bipartitions. We search for those (maximally multipartite entangled) states whose purity is minimum for all bipartitions and recast this optimization problem into a problem of statistical mechanics

  13. Entanglement transfer between bipartite systems

    International Nuclear Information System (INIS)

    Bougouffa, Smail; Ficek, Zbigniew

    2012-01-01

    The problem of a controlled transfer of an entanglement initially encoded into two two-level atoms that are successively sent through two single-mode cavities is investigated. The atoms and the cavity modes form a four-qubit system and we demonstrate the conditions under which the initial entanglement encoded into the atoms can be completely transferred to other pairs of qubits. We find that in the case of non-zero detuning between the atomic transition frequencies and the cavity mode frequencies, no complete transfer of the initial entanglement is possible to any of the other pairs of qubits. In the case of exact resonance and equal coupling strengths of the atoms to the cavity modes, an initial maximally entangled state of the atoms can be completely transferred to the cavity modes. Complete transfer of the entanglement is restricted to the cavity modes, with transfer to the other pairs being limited to 50%. We find that complete transfer of an initial entanglement to other pairs of qubits may take place if the initial state is not the maximally entangled state and the atoms couple to the cavity modes with unequal strengths. Depending on the ratio between the coupling strengths, optimal entanglement can be created between the atoms and one of the cavity modes.

  14. Generic entangling through quantum indistinguishability

    Indian Academy of Sciences (India)

    quantum systems (methods such as entanglement swapping [5] fall in this ... continued till the particles anti-bunch, in which case they are entangled. 2. .... in the context of the scattering of ballistic electrons from a magnetic impurity in a semi-.

  15. Emergence of Symmetries from Entanglement

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    Maximal Entanglement appears to be a key ingredient for the emergence of symmetries. We first illustrate this phenomenon using two examples: the emergence of conformal symmetry in condensed matter systems and  the relation of tensor networks to holography. We further present a Principle of Maximal Entanglement that seems to dictate to a large extend the structure of gauge symmetry.

  16. Spin-photon entangling diode

    DEFF Research Database (Denmark)

    Flindt, Christian; Sørensen, A. S.; Lukin, M. D.

    2007-01-01

    We propose a semiconductor device that can electrically generate entangled electron spin-photon states, providing a building block for entanglement of distant spins. The device consists of a p-i-n diode structure that incorporates a coupled double quantum dot. We show that electronic control of t...

  17. Entanglement entropy and duality

    Energy Technology Data Exchange (ETDEWEB)

    Radičević, Ðorđe [Stanford Institute for Theoretical Physics and Department of Physics, Stanford University, Stanford, CA 94305-4060 (United States)

    2016-11-22

    Using the algebraic approach to entanglement entropy, we study several dual pairs of lattice theories and show how the entropy is completely preserved across each duality. Our main result is that a maximal algebra of observables in a region typically dualizes to a non-maximal algebra in a dual region. In particular, we show how the usual notion of tracing out external degrees of freedom dualizes to a tracing out coupled to an additional summation over superselection sectors. We briefly comment on possible extensions of our results to more intricate dualities, including holographic ones.

  18. High dimensional entanglement

    CSIR Research Space (South Africa)

    Mc

    2012-07-01

    Full Text Available stream_source_info McLaren_2012.pdf.txt stream_content_type text/plain stream_size 2190 Content-Encoding ISO-8859-1 stream_name McLaren_2012.pdf.txt Content-Type text/plain; charset=ISO-8859-1 High dimensional... entanglement M. McLAREN1,2, F.S. ROUX1 & A. FORBES1,2,3 1. CSIR National Laser Centre, PO Box 395, Pretoria 0001 2. School of Physics, University of the Stellenbosch, Private Bag X1, 7602, Matieland 3. School of Physics, University of Kwazulu...

  19. Spacetime equals entanglement

    Energy Technology Data Exchange (ETDEWEB)

    Nomura, Yasunori [Berkeley Center for Theoretical Physics, Department of Physics, University of California, Berkeley, CA 94720 (United States); Theoretical Physics Group, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo Institutes for Advanced Study, Kashiwa 277-8583 (Japan); Salzetta, Nico, E-mail: nsalzetta@berkeley.edu [Berkeley Center for Theoretical Physics, Department of Physics, University of California, Berkeley, CA 94720 (United States); Theoretical Physics Group, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Sanches, Fabio; Weinberg, Sean J. [Berkeley Center for Theoretical Physics, Department of Physics, University of California, Berkeley, CA 94720 (United States); Theoretical Physics Group, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

    2016-12-10

    We study the Hilbert space structure of classical spacetimes under the assumption that entanglement in holographic theories determines semiclassical geometry. We show that this simple assumption has profound implications; for example, a superposition of classical spacetimes may lead to another classical spacetime. Despite its unconventional nature, this picture admits the standard interpretation of superpositions of well-defined semiclassical spacetimes in the limit that the number of holographic degrees of freedom becomes large. We illustrate these ideas using a model for the holographic theory of cosmological spacetimes.

  20. Meilensteine in der Erforschung der kompakten Objekte

    Science.gov (United States)

    Camenzind, Max

    Kompakte Objekte besitzen zum einen eine sehr hohe Dichte, und zum anderen sind sie durch die Tatsache charakterisiert, dass keine nuklearen Reaktionen mehr in ihrem Inneren stattfinden können. Aus diesem Grund können sie im Unterschied zu gewöhnlichen Sternen der Gravitation nicht mehr mit dem Druck des thermischen Gases widerstehen. In den Weißen Zwergen bzw. Neutronensternen wird der Gravitation der Quantendruck eines Elektronengases bzw. einer Neutronenflüssigkeit entgegengesetzt. Ein solches Gas besteht aus Elektronen bzw. Neutronen, die auf ihr niedrigstes Energieniveau zusammengepresst wurden. Durch die daraus resultierende hohe Bewegungsenergie der Fermionen wird der sogenannte Quantendruck erzeugt.

  1. Der digitalisierte Forscher

    Directory of Open Access Journals (Sweden)

    Storr, Stefan

    2017-12-01

    Full Text Available Der vorliegende Kommentar bezieht sich auf den Beitrag „Der digitalisierte Forscher“ von Thomas Kröll (ALJ 2/2017, 71. Ausgehend von der Beschreibung der gegenwärtigen Gesellschaft als Wissensgesellschaft werden drei Aspekte angeführt, die die Wissenschaft als System heute kennzeichnen und künftig weitere Bedeutung haben werden: die Gewinnung und Weitergabe von Forschungsdaten, die Bewertung von wissenschaftlichen Leistungen und die Funktion von Universitäten. Der Kommentar schließt mit der Aufforderung, das Grundrecht der Wissenschaftsfreiheit als institutionelle Garantie fortzuentwickeln.

  2. Parkways und Freeways in der Bestimmung der Landschaft der Amerikanischen Grossstaedte. Der Fall Boston.

    Directory of Open Access Journals (Sweden)

    Massimo Maria Brignoli

    2012-08-01

    Full Text Available Die Tradition der amerikanischen Landschaftarchitektur hatt aus Boston ein Planungsexperiment gemacht. Das Emerald Necklace, eine echte Ikone der Landschaftsarchitektur, bezeugt immer noch wirkungsvoll, wie die Landschaftsplanung die Struktur moderner Grossstaedte mit Raum zum wohnen staerken kann. Heute muss die Stadt mit ihren von der Central Artery hervorgerufenen Wunden fertigwerden, mit Risultaten, die wahrscheinlich nicht der Groesse ihrer Geschichte entsprechen. Der teilweise Erfolg der Rose Kennedy Greenway macht die Notwendigkeit klar, die Regelung fuer die Planung der offenen Gebiete neu zu bestimmen.

  3. Entanglements in Conjugated Polymers

    Science.gov (United States)

    Xie, Renxuan; Lee, Youngmin; Aplan, Melissa; Caggiano, Nick; Gomez, Enrique; Colby, Ralph

    Conjugated polymers, such as poly(3-hexylthiophene-2,5-diyl) (P3HT) and poly-((9,9-dioctylfluorene)-2,7-diyl-alt-[4,7-bis(thiophen-5-yl)-2,1,3-benzothiadiazole]-2',2''-diyl) (PFTBT), are widely used as hole and electron transport materials in a variety of electronic devices. However, fundamental knowledge regarding chain entanglements and nematic-to-isotropic transition is still lacking and are crucial to maximize charge transport properties. A systematic melt rheology study on P3HT with various molecular weights and regio regularities was performed. We find that the entanglement molecular weight Me is 5.0 kg/mol for regiorandom P3HT, but the apparent Me for regioregular P3HT is significantly higher. The difference is postulated to arise from the presence of a nematic phase only in regioregular P3HT. Analogously, PFTBT shows a clear rheological signature of the nematic-to-isotropic transition as a reversible sharp transition at 278 C. Shearing of this nematic phase leads to anisotropic crystalline order in PFTBT. We postulate that aligning the microstructure will impact charge transport and thereby advance the field of conducting polymers. National Science Foundation.

  4. Experimental entanglement distillation of mesoscopic quantum states

    DEFF Research Database (Denmark)

    Dong, Ruifang; Lassen, Mikael Østergaard; Heersink, Joel

    2008-01-01

    channel, the distribution of loss-intolerant entangled states is inevitably afflicted by decoherence, which causes a degradation of the transmitted entanglement. To combat the decoherence, entanglement distillation, a process of extracting a small set of highly entangled states from a large set of less...... entangled states, can be used(4-14). Here we report on the distillation of deterministically prepared light pulses entangled in continuous variables that have undergone non-Gaussian noise. The entangled light pulses(15-17) are sent through a lossy channel, where the transmission is varying in time similarly...

  5. Ekspresionizmo apibrėžtys ir tyrinėjimai XX a. vokiečių literatūros kritikoje | Definitionen und Darstellungsformen des Expressionismus in der deutschen Literaturkritik des 20. Jahrhunderts

    Directory of Open Access Journals (Sweden)

    Jadvyga Bajarūnienė

    2004-01-01

    Full Text Available Die deutsche Literatur des 20. Jahrhunderts ist entscheidend durch den Expressionismus (1910–1925 geprägt. Seine Formierung und Entfaltung wurde von Anfang an von einer starken theoretischen Reflexion begleitet. Das wesentliche Merkmal der zeitgenössischen Manifeste und Dokumente war die Bestrebung, den Expressionismus von den anderen Richtungen und Tendenzen der Zeit abzugrenzen und die Andersartigkeit der „Ausdruckskunst“ hervorzuheben. Die Bezeichnungen des Expressionismus wurden vielfach durch die Schlagwörter „Wesen“, „Bewegung“, „Vision“, „der neue Mensch“ u. a. bestimmt. Im Jahre 1933 wurde die Rezeption des Expressionismus in Deutschland zwangsweise unterbrochen und konnte erst nach 1945 wieder einsetzen.Die Darstellungsformen des Expressionismus in der deutschen Literaturkritik richteten sich je nach der dominierenden Literaturmethode. So rückt am Ende der 50er und in den 60er Jahren unter dem Einfluss der werkimmanenten Kritik die Stil- und Formfrage in den Vordergrund. Man versucht, die stilistischen Dominanten der einzelnen Gattungen sowie des individuellen Schaffens einzelner Autoren herauszuarbeiten. Jedoch zeichnet sich auch die Tendenz ab, die Literatur des Expressionismus im Zusammenhang mit anderen Bereichen der Kunst (Malerei und Musik, derWissenschaft (Philosophie, Soziologie, der Technik zu betrachten. Die 70er Jahre gelten in der deutschen Literaturwissenschaft als eine Kulmination der Expressionismusforschung. Silvio Vietta und Hans-Georg Kemper modifizieren zum Teil den Begriff und meinen, dass man die Literatur des Expressionismus nicht aus dem Epochenzusammenhang lösen darf. Der Expressionismus kann erst im Kontext der zeitgenössischen Wissenschaft, Philosophie, Soziologie und Massenkultur adäquat erschlossen werden; am sinnvollsten erscheint dabei die hermeneutische Methode. Wolfgang Rothe ist der Ansicht, dass der Expressionismus keineswegs nur als ein auf die Sprachkunst beschr

  6. Squashed entanglement in infinite dimensions

    International Nuclear Information System (INIS)

    Shirokov, M. E.

    2016-01-01

    We analyse two possible definitions of the squashed entanglement in an infinite-dimensional bipartite system: direct translation of the finite-dimensional definition and its universal extension. It is shown that the both definitions produce the same lower semicontinuous entanglement measure possessing all basis properties of the squashed entanglement on the set of states having at least one finite marginal entropy. It is also shown that the second definition gives an adequate lower semicontinuous extension of this measure to all states of the infinite-dimensional bipartite system. A general condition relating continuity of the squashed entanglement to continuity of the quantum mutual information is proved and its corollaries are considered. Continuity bound for the squashed entanglement under the energy constraint on one subsystem is obtained by using the tight continuity bound for quantum conditional mutual information (proved in the Appendix by using Winter’s technique). It is shown that the same continuity bound is valid for the entanglement of formation. As a result the asymptotic continuity of the both entanglement measures under the energy constraint on one subsystem is proved.

  7. Graphical Classification of Entangled Qutrits

    Directory of Open Access Journals (Sweden)

    Kentaro Honda

    2012-10-01

    Full Text Available A multipartite quantum state is entangled if it is not separable. Quantum entanglement plays a fundamental role in many applications of quantum information theory, such as quantum teleportation. Stochastic local quantum operations and classical communication (SLOCC cannot essentially change quantum entanglement without destroying it. Therefore, entanglement can be classified by dividing quantum states into equivalence classes, where two states are equivalent if each can be converted into the other by SLOCC. Properties of this classification, especially in the case of non two-dimensional quantum systems, have not been well studied. Graphical representation is sometimes used to clarify the nature and structural features of entangled states. SLOCC equivalence of quantum bits (qubits has been described graphically via a connection between tripartite entangled qubit states and commutative Frobenius algebras (CFAs in monoidal categories. In this paper, we extend this method to qutrits, i.e., systems that have three basis states. We examine the correspondence between CFAs and tripartite entangled qutrits. Using the symmetry property, which is required by the definition of a CFA, we find that there are only three equivalence classes that correspond to CFAs. We represent qutrits graphically, using the connection to CFAs. We derive equations that characterize the three equivalence classes. Moreover, we show that any qutrit can be represented as a composite of three graphs that correspond to the three classes.

  8. Entanglement in a Dimerized Antiferromagnetic Heisenberg Chain

    OpenAIRE

    Hao, Xiang; Zhu, Shiqun

    2008-01-01

    The entanglement properties in an antiferromagnetic dimerized Heisenberg spin-1/2 chain are investigated. The entanglement gap, which is the difference between the ground-state energy and the minimal energy that any separable state can attain, is calculated to detect the entanglement. It is found that the entanglement gap can be increased by varying the alternation parameter. Through thermal energy, the witness of the entanglement can determine a characteristic temperature below that an entan...

  9. Local cloning of entangled states

    International Nuclear Information System (INIS)

    Gheorghiu, Vlad; Yu Li; Cohen, Scott M.

    2010-01-01

    We investigate the conditions under which a set S of pure bipartite quantum states on a DxD system can be locally cloned deterministically by separable operations, when at least one of the states is full Schmidt rank. We allow for the possibility of cloning using a resource state that is less than maximally entangled. Our results include that: (i) all states in S must be full Schmidt rank and equally entangled under the G-concurrence measure, and (ii) the set S can be extended to a larger clonable set generated by a finite group G of order |G|=N, the number of states in the larger set. It is then shown that any local cloning apparatus is capable of cloning a number of states that divides D exactly. We provide a complete solution for two central problems in local cloning, giving necessary and sufficient conditions for (i) when a set of maximally entangled states can be locally cloned, valid for all D; and (ii) local cloning of entangled qubit states with nonvanishing entanglement. In both of these cases, we show that a maximally entangled resource is necessary and sufficient, and the states must be related to each other by local unitary 'shift' operations. These shifts are determined by the group structure, so need not be simple cyclic permutations. Assuming this shifted form and partially entangled states, then in D=3 we show that a maximally entangled resource is again necessary and sufficient, while for higher-dimensional systems, we find that the resource state must be strictly more entangled than the states in S. All of our necessary conditions for separable operations are also necessary conditions for local operations and classical communication (LOCC), since the latter is a proper subset of the former. In fact, all our results hold for LOCC, as our sufficient conditions are demonstrated for LOCC, directly.

  10. Literatūros mokslas ir teologija: dialogiško santykio realijos ir krikščioniškos mistinės tradicijos laukas. Literaturwissenschaft und Theologie: Realien des dialogischen Verhältnisses und das Feld der mystischen Erfahrung

    Directory of Open Access Journals (Sweden)

    Dalia Jakaitė

    2011-01-01

    Full Text Available Das wichtigste Ziel des vorliegenden Artikels ist eine Bedeutung der Mystik für die Autoren des Dialogs zwischen der Literatur(wissenschaft und Theologie zu zeigen. Dabei wird die Tradition der frühchristlichen Kirche aktualisiert. Die christliche Tradition der Mystik kommt schon in der Bibel zum Vorschein, so z. B. in der Paulusrede auf dem Areopag, die mit der Literaturtheologie in Beziehung gesetzt wird. Als Untersuchungsgegenstand dienen theoretische Studien und einige Arbeiten der Literaturkritik. Die Erfahrung erscheint als ein wesentliches Problem im Bereich der Literatur und Theologie.Kuschel, als Verbindungskette zweier bedeutungsvoller Forschungsetappen des Dialogs zwischen Literatur und Theologie in Deutschland, formuliert einen sich dynamisch verändernden Netz der strukturellen Analogien, der Theopoetik und anderer Begriffe. Als eine der wichtigsten Säulen dient in seinen Arbeiten die Steiners Konzeption der Kunstmetaphysik, die auch für andere nach einem interdisziplinären Dialog suchenden Autoren aktuell ist. Braungart betont die ästhetische Richtung der Theologie, die Literaturwissenschaft wird laut Braungart in Zusammenhang mit ästhetisch und exegetisch-hermeneutisch orientierter Theologie gesetzt. Das ästhetische Kriterium für die Bewertung der Literatur wird in Arbeiten von Sölle durch ein starkes theologisches Interesse ergänzt. Diese Autorin sucht nach Unterstützung des dialogischen Denkens und bedient sich der figurischen Methode in Auffassung von Auerbach. Im Rahmen dieser Problematik wird kontraverse Betrachtung des Begriffs der Literaturtheologie deutlich, zum Verständnis dessen Mieths Ansicht von großer Bedeutung ist. Seiner Meinung nach sei die Literaturtheologie ohne Autonomie der Poesie nicht zu gerechtfertigen, Theologie sei genausoviel ideologisch gefährlich wie gefährlich eine für die Literaturwissenschaft typische leere Ideologie sei.Die Mystik der Kircheenväter und des Mittelaters weist

  11. Zero modes and entanglement entropy

    Energy Technology Data Exchange (ETDEWEB)

    Yazdi, Yasaman K. [Perimeter Institute for Theoretical Physics,31 Caroline St. N., Waterloo, ON, N2L 2Y5 (Canada); Department of Physics and Astronomy, University of Waterloo,200 University Avenue West, Waterloo, ON, N2L 3G1 (Canada)

    2017-04-26

    Ultraviolet divergences are widely discussed in studies of entanglement entropy. Also present, but much less understood, are infrared divergences due to zero modes in the field theory. In this note, we discuss the importance of carefully handling zero modes in entanglement entropy. We give an explicit example for a chain of harmonic oscillators in 1D, where a mass regulator is necessary to avoid an infrared divergence due to a zero mode. We also comment on a surprising contribution of the zero mode to the UV-scaling of the entanglement entropy.

  12. Slow Images and Entangled Photons

    International Nuclear Information System (INIS)

    Swordy, Simon

    2007-01-01

    I will discuss some recent experiments using slow light and entangled photons. We recently showed that it was possible to map a two dimensional image onto very low light level signals, slow them down in a hot atomic vapor while preserving the amplitude and phase of the images. If time remains, I will discuss some of our recent work with time-energy entangled photons for quantum cryptography. We were able to show that we could have a measurable state space of over 1000 states for a single pair of entangled photons in fiber.

  13. Teleportation of Squeezed Entangled State

    Institute of Scientific and Technical Information of China (English)

    HU Li-Yun; ZHOU Nan-Run

    2007-01-01

    Based on the coherent entangled state |α, x> we introduce the squeezed entangled state (SES). Then we propose a teleportation protocol for the SES by using Einstein-Podolsky-Rosen entangled state |η>as a quantum channel.The calculation is greatly simplified by virtue of the Schmidt decompositions of both |α, x>and |η>. Any bipartite states that can be expanded in terms of |α, x>may be teleported in this way due to the completeness of |α, x>.

  14. Bound entanglement and local realism

    International Nuclear Information System (INIS)

    Kaszlikowski, Dagomir; Zukowski, Marek; Gnacinski, Piotr

    2002-01-01

    We show using a numerical approach, which gives necessary and sufficient conditions for the existence of local realism, that the bound entangled state presented in Bennett et al. [Phys. Rev. Lett. 82, 5385 (1999)] admits a local and realistic description. We also find the lowest possible amount of some appropriate entangled state that must be ad-mixed to the bound entangled state so that the resulting density operator has no local and realistic description and as such can be useful in quantum communication and quantum computation

  15. Gaussian entanglement revisited

    Science.gov (United States)

    Lami, Ludovico; Serafini, Alessio; Adesso, Gerardo

    2018-02-01

    We present a novel approach to the separability problem for Gaussian quantum states of bosonic continuous variable systems. We derive a simplified necessary and sufficient separability criterion for arbitrary Gaussian states of m versus n modes, which relies on convex optimisation over marginal covariance matrices on one subsystem only. We further revisit the currently known results stating the equivalence between separability and positive partial transposition (PPT) for specific classes of Gaussian states. Using techniques based on matrix analysis, such as Schur complements and matrix means, we then provide a unified treatment and compact proofs of all these results. In particular, we recover the PPT-separability equivalence for: (i) Gaussian states of 1 versus n modes; and (ii) isotropic Gaussian states. In passing, we also retrieve (iii) the recently established equivalence between separability of a Gaussian state and and its complete Gaussian extendability. Our techniques are then applied to progress beyond the state of the art. We prove that: (iv) Gaussian states that are invariant under partial transposition are necessarily separable; (v) the PPT criterion is necessary and sufficient for separability for Gaussian states of m versus n modes that are symmetric under the exchange of any two modes belonging to one of the parties; and (vi) Gaussian states which remain PPT under passive optical operations can not be entangled by them either. This is not a foregone conclusion per se (since Gaussian bound entangled states do exist) and settles a question that had been left unanswered in the existing literature on the subject. This paper, enjoyable by both the quantum optics and the matrix analysis communities, overall delivers technical and conceptual advances which are likely to be useful for further applications in continuous variable quantum information theory, beyond the separability problem.

  16. Transgenerationale Wertevermittlung in der Familie

    DEFF Research Database (Denmark)

    Demuth, Carolin

    2013-01-01

    Der vorliegende Beitrag geht der Frage nach, inwiefern sich in den biografisch-narrativen Konstruktionen junger Erwachsener transgenerationale Aspekte der Identifizierung bzw. Abgrenzung zu den Wertevorstellungen der Ursprungsfamilie finden lassen. Besonderes Augenmerk liegt hierbei auf den Dimen...

  17. Entangled Bessel-Gaussian beams

    CSIR Research Space (South Africa)

    McLaren, M

    2012-10-01

    Full Text Available by performing a Bell-type experiment and showing a violation of the Clauser-Horne-Shimony-Holt inequality. In addition, we use quantum state tomography to indicate higher-dimensional entanglement in terms of BG modes....

  18. Gaussian entanglement distribution via satellite

    Science.gov (United States)

    Hosseinidehaj, Nedasadat; Malaney, Robert

    2015-02-01

    In this work we analyze three quantum communication schemes for the generation of Gaussian entanglement between two ground stations. Communication occurs via a satellite over two independent atmospheric fading channels dominated by turbulence-induced beam wander. In our first scheme, the engineering complexity remains largely on the ground transceivers, with the satellite acting simply as a reflector. Although the channel state information of the two atmospheric channels remains unknown in this scheme, the Gaussian entanglement generation between the ground stations can still be determined. On the ground, distillation and Gaussification procedures can be applied, leading to a refined Gaussian entanglement generation rate between the ground stations. We compare the rates produced by this first scheme with two competing schemes in which quantum complexity is added to the satellite, thereby illustrating the tradeoff between space-based engineering complexity and the rate of ground-station entanglement generation.

  19. Continuous-Variable Entanglement Swapping

    Directory of Open Access Journals (Sweden)

    Kevin Marshall

    2015-05-01

    Full Text Available We present a very brief overview of entanglement swapping as it relates to continuous-variable quantum information. The technical background required is discussed and the natural link to quantum teleportation is established before discussing the nature of Gaussian entanglement swapping. The limitations of Gaussian swapping are introduced, along with the general applications of swapping in the context of to quantum communication and entanglement distribution. In light of this, we briefly summarize a collection of entanglement swapping schemes which incorporate a non-Gaussian ingredient and the benefits of such schemes are noted. Finally, we motivate the need to further study and develop such schemes by highlighting requirements of a continuous-variable repeater.

  20. Quantum entanglement and quantum teleportation

    International Nuclear Information System (INIS)

    Shih, Y.H.

    2001-01-01

    One of the most surprising consequences of quantum mechanics is the entanglement of two or more distance particles. The ''ghost'' interference and the ''ghost'' image experiments demonstrated the astonishing nonlocal behavior of an entangled photon pair. Even though we still have questions in regard to fundamental issues of the entangled quantum systems, quantum entanglement has started to play important roles in quantum information and quantum computation. Quantum teleportation is one of the hot topics. We have demonstrated a quantum teleportation experiment recently. The experimental results proved the working principle of irreversibly teleporting an unknown arbitrary quantum state from one system to another distant system by disassembling into and then later reconstructing from purely classical information and nonclassical EPR correlations. The distinct feature of this experiment is that the complete set of Bell states can be distinguished in the Bell state measurement. Teleportation of a quantum state can thus occur with certainty in principle. (orig.)

  1. Entanglement scaling in lattice systems

    Energy Technology Data Exchange (ETDEWEB)

    Audenaert, K M R [Institute for Mathematical Sciences, Imperial College London, 53 Prince' s Gate, Exhibition Road, London SW7 2PG (United Kingdom); Cramer, M [QOLS, Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BW (United Kingdom); Eisert, J [Institute for Mathematical Sciences, Imperial College London, 53 Prince' s Gate, Exhibition Road, London SW7 2PG (United Kingdom); Plenio, M B [Institute for Mathematical Sciences, Imperial College London, 53 Prince' s Gate, Exhibition Road, London SW7 2PG (United Kingdom)

    2007-05-15

    We review some recent rigorous results on scaling laws of entanglement properties in quantum many body systems. More specifically, we study the entanglement of a region with its surrounding and determine its scaling behaviour with its size for systems in the ground and thermal states of bosonic and fermionic lattice systems. A theorem connecting entanglement between a region and the rest of the lattice with the surface area of the boundary between the two regions is presented for non-critical systems in arbitrary spatial dimensions. The entanglement scaling in the field limit exhibits a peculiar difference between fermionic and bosonic systems. In one-spatial dimension a logarithmic divergence is recovered for both bosonic and fermionic systems. In two spatial dimensions in the setting of half-spaces however we observe strict area scaling for bosonic systems and a multiplicative logarithmic correction to such an area scaling in fermionic systems. Similar questions may be posed and answered in classical systems.

  2. Transverse correlations in multiphoton entanglement

    International Nuclear Information System (INIS)

    Wen Jianming; Rubin, Morton H.; Shih Yanhua

    2007-01-01

    We have analyzed the transverse correlation in multiphoton entanglement. The generalization of quantum ghost imaging is extended to the N-photon state. The Klyshko's two-photon advanced-wave picture is generalized to the N-photon case

  3. Entanglement distribution in quantum networks

    International Nuclear Information System (INIS)

    Perseguers, Sebastien

    2010-01-01

    This Thesis contributes to the theory of entanglement distribution in quantum networks, analyzing the generation of long-distance entanglement in particular. We consider that neighboring stations share one partially entangled pair of qubits, which emphasizes the difficulty of creating remote entanglement in realistic settings. The task is then to design local quantum operations at the stations, such that the entanglement present in the links of the whole network gets concentrated between few parties only, regardless of their spatial arrangement. First, we study quantum networks with a two-dimensional lattice structure, where quantum connections between the stations (nodes) are described by non-maximally entangled pure states (links). We show that the generation of a perfectly entangled pair of qubits over an arbitrarily long distance is possible if the initial entanglement of the links is larger than a threshold. This critical value highly depends on the geometry of the lattice, in particular on the connectivity of the nodes, and is related to a classical percolation problem. We then develop a genuine quantum strategy based on multipartite entanglement, improving both the threshold and the success probability of the generation of long-distance entanglement. Second, we consider a mixed-state definition of the connections of the quantum networks. This formalism is well-adapted for a more realistic description of systems in which noise (random errors) inevitably occurs. New techniques are required to create remote entanglement in this setting, and we show how to locally extract and globally process some error syndromes in order to create useful long-distance quantum correlations. Finally, we turn to networks that have a complex topology, which is the case for most real-world communication networks such as the Internet for instance. Besides many other characteristics, these systems have in common the small-world feature, stating that any two nodes are separated by a

  4. Entanglement distribution in quantum networks

    Energy Technology Data Exchange (ETDEWEB)

    Perseguers, Sebastien

    2010-04-15

    This Thesis contributes to the theory of entanglement distribution in quantum networks, analyzing the generation of long-distance entanglement in particular. We consider that neighboring stations share one partially entangled pair of qubits, which emphasizes the difficulty of creating remote entanglement in realistic settings. The task is then to design local quantum operations at the stations, such that the entanglement present in the links of the whole network gets concentrated between few parties only, regardless of their spatial arrangement. First, we study quantum networks with a two-dimensional lattice structure, where quantum connections between the stations (nodes) are described by non-maximally entangled pure states (links). We show that the generation of a perfectly entangled pair of qubits over an arbitrarily long distance is possible if the initial entanglement of the links is larger than a threshold. This critical value highly depends on the geometry of the lattice, in particular on the connectivity of the nodes, and is related to a classical percolation problem. We then develop a genuine quantum strategy based on multipartite entanglement, improving both the threshold and the success probability of the generation of long-distance entanglement. Second, we consider a mixed-state definition of the connections of the quantum networks. This formalism is well-adapted for a more realistic description of systems in which noise (random errors) inevitably occurs. New techniques are required to create remote entanglement in this setting, and we show how to locally extract and globally process some error syndromes in order to create useful long-distance quantum correlations. Finally, we turn to networks that have a complex topology, which is the case for most real-world communication networks such as the Internet for instance. Besides many other characteristics, these systems have in common the small-world feature, stating that any two nodes are separated by a

  5. Jungen als Verlierer? Die Diskussion um die Benachteiligung von Jungen in der Schule

    Directory of Open Access Journals (Sweden)

    Hilde von Balluseck

    2009-03-01

    Full Text Available Die im Vergleich zu den Mädchen schlechteren Schulleistungen von Jungen werden in der öffentlichen Diskussion häufig dem weiblichen Geschlecht von pädagogischen Fachkräften angelastet. Das Leistungs- und Sozialverhalten der meisten Jungen ist jedoch weitaus stärker durch Männer- und Frauenbilder in ihrem sozialen Umfeld bedingt. Wenn diese sich an hegemonialen Vorstellungen von Männlichkeit – gerade auch in der gesellschaftlich ohnmächtigen Unterschicht – orientieren, geraten Jungen in der Schule in einen Konflikt. Dieser wird verstärkt, wenn sie – statistisch häufiger als Mädchen – zu Hause geschlagen werden. Der im Vergleich zu Mädchen weitaus intensivere Konsum von Gewalt verherrlichenden Medien ist ein weiterer Faktor für die größere Schuldistanz von Jungen. Die pauschalisierende Annahme, das weniger angepasste Leistungsverhalten von Jungen stehe im direkten Zusammenhang mit dem weiblichen Geschlecht der Lehrkräfte, geht somit an den eigentlichen Problemen vorbei.In the public discussions about the relatively poor school achievements of boys as compared to girls, the female gender of the pedagogical specialists is often blamed. Most of the boys’ social performance and attitude toward achievement is, however, conditioned through images of men and women in their immediate social surroundings. Boys often find themselves in conflict at school when these images are oriented toward hegemonic conceptions of masculinity, in particular when found in the socially powerless underclass. This conflict is heightened when the boys are abused at home, statistically more likely to happen than in the case of girls. Another factor for the boys’ greater distancing from schools is their higher consumption of media forms that glorify violence. The trivializing assumption that the poorer achievements of boys are directly related to the female gender of the teachers thus ignores the true problems.

  6. Estimating localizable entanglement from witnesses

    OpenAIRE

    Amaro, David; Müller, Markus; Pal, Amit Kumar

    2018-01-01

    Computing localizable entanglement for noisy many-particle quantum states is difficult due to the optimization over all possible sets of local projection measurements. Therefore, it is crucial to develop lower bounds, which can provide useful information about the behaviour of localizable entanglement, and which can be determined by measuring a limited number of operators, or by performing least number of measurements on the state, preferably without performing a full state tomography. In thi...

  7. Minimal tomography with entanglement witnesses

    OpenAIRE

    Zhu, Huangjun; Teo, Yong Siah; Englert, Berthold-Georg

    2009-01-01

    We introduce informationally complete measurements whose outcomes are entanglement witnesses and so answer the question of how many witnesses need to be measured to decide whether an arbitrary state is entangled or not: as many as the dimension of the state space. The optimized witness-based measurement can provide exponential improvement with respect to witness efficiency in high-dimensional Hilbert spaces, at the price of a reduction in the tomographic efficiency. We describe a systematic c...

  8. Combined intraoperative and external irradiation of the celiac artery in the rabbit: Effects on gastric mucosal blood flow; Kombinierte intraoperative und externe Bestrahlung der Arteria coeliaca beim Kaninchen: Auswirkungen auf die Durchblutung der Magenschleimhaut

    Energy Technology Data Exchange (ETDEWEB)

    Doerr, W. [Universitaetsklinikum Carl Gustav Carus, Dresden (Germany). Klinik und Poliklinik fuer Strahlentherapie]|[GSF-Inst. fuer Strahlenbiologie, Oberschleissheim (Germany); Kallfass, E. [GSF-Inst. fuer Strahlenbiologie, Oberschleissheim (Germany); Berg, D. [GSF-Inst. fuer Strahlenbiologie, Oberschleissheim (Germany); Kummermehr, J. [GSF-Inst. fuer Strahlenbiologie, Oberschleissheim (Germany)

    1996-12-01

    Aim: To demonstrate changes in gastric mucosal blood flow caused by intraoperative radiotherapy of the celiac artery combined with external radiotherapy of the upper abdomen in a rabbit model. The study was designed to identify a possible correlation between a radiation-induced reduction in mucosal blood flow and the induction of gastric ulcer. Material and Method: Intraoperative radiation doses of 0 or 30 Gy were given to the celiac artery in rabbits. After a delay of 14 days external radiotherapy of the upper abdomen with 3x4 Gy/week to a maximum total dose of 40 Gy was initiated. Gastric mucosal blood flow was assessed by intraventricular injection of radioactively-labelled microspheres (15 {mu}m) followed by measurement of radioactivity in the mucosa. The injections were performed at various time intervals between 2 and 63 days after intraoperative radiation. Results: Intraoperative radiotherapy, including sham-intraoperative radiation, resulted in a transitory reduction of mucosal blood flow by about 50% of the control value on day 7. After a temporary recovery by day 14, a marked and permanent reduction in blood flow was assessed after week 6. This time corresponds to the time of development of gastric ulcer. Conclusions: A relationship between the time of ulcer development and of reduced gastric mucosal blood flow was observed after combined intraoperative and external radiotherapy. The mechanical component of intraoperative treatment has to be emphasized. Reduced blood flow was also seen after intraoperative radiotherapy alone, without an induction of ulcer by this treatment. Hence additional mucosal damage by external radiation must be present for the induction of gastric ulcer. (orig.) [Deutsch] Ziel: Untersuchung der Veraenderungen der Magenschleimhautdurchblutung am Kaninchen als Folge einer kombinierten intraoperativen Bestrahlung der Arteria coeliaca und externen Bestrahlung des Oberbauchs. Durch diesen Ansatz sollte ein moeglicher Zusammenhang

  9. Entanglement as a signature of quantum chaos.

    Science.gov (United States)

    Wang, Xiaoguang; Ghose, Shohini; Sanders, Barry C; Hu, Bambi

    2004-01-01

    We explore the dynamics of entanglement in classically chaotic systems by considering a multiqubit system that behaves collectively as a spin system obeying the dynamics of the quantum kicked top. In the classical limit, the kicked top exhibits both regular and chaotic dynamics depending on the strength of the chaoticity parameter kappa in the Hamiltonian. We show that the entanglement of the multiqubit system, considered for both the bipartite and the pairwise entanglement, yields a signature of quantum chaos. Whereas bipartite entanglement is enhanced in the chaotic region, pairwise entanglement is suppressed. Furthermore, we define a time-averaged entangling power and show that this entangling power changes markedly as kappa moves the system from being predominantly regular to being predominantly chaotic, thus sharply identifying the edge of chaos. When this entangling power is averaged over all states, it yields a signature of global chaos. The qualitative behavior of this global entangling power is similar to that of the classical Lyapunov exponent.

  10. Pseudo-entanglement evaluated in noninertial frames

    International Nuclear Information System (INIS)

    Mehri-Dehnavi, Hossein; Mirza, Behrouz; Mohammadzadeh, Hosein; Rahimi, Robabeh

    2011-01-01

    Research highlights: → We study pseudo-entanglement in noninertial frames. → We examine different measures of entanglement and nonclassical correlation for the state. → We find the threshold for entanglement is changed in noninertial frames. → We also describe the behavior of local unitary classes of states in noninertial frames. - Abstract: We study quantum discord, in addition to entanglement, of bipartite pseudo-entanglement in noninertial frames. It is shown that the entanglement degrades from its maximum value in a stationary frame to a minimum value in an infinite accelerating frame. There is a critical region found in which, for particular cases, entanglement of states vanishes for certain accelerations. The quantum discord of pseudo-entanglement decreases by increasing the acceleration. Also, for a physically inaccessible region, entanglement and nonclassical correlation are evaluated and shown to match the corresponding values of the physically accessible region for an infinite acceleration.

  11. Mixtures of maximally entangled pure states

    Energy Technology Data Exchange (ETDEWEB)

    Flores, M.M., E-mail: mflores@nip.up.edu.ph; Galapon, E.A., E-mail: eric.galapon@gmail.com

    2016-09-15

    We study the conditions when mixtures of maximally entangled pure states remain entangled. We found that the resulting mixed state remains entangled when the number of entangled pure states to be mixed is less than or equal to the dimension of the pure states. For the latter case of mixing a number of pure states equal to their dimension, we found that the mixed state is entangled provided that the entangled pure states to be mixed are not equally weighted. We also found that one can restrict the set of pure states that one can mix from in order to ensure that the resulting mixed state is genuinely entangled. Also, we demonstrate how these results could be applied as a way to detect entanglement in mixtures of the entangled pure states with noise.

  12. Quantum entanglement of identical particles

    International Nuclear Information System (INIS)

    Shi Yu

    2003-01-01

    We consider entanglement in a system with a fixed number of identical particles. Since any operation should be symmetrized over all the identical particles and there is the precondition that the spatial wave functions overlap, the meaning of identical-particle entanglement is fundamentally different from that of distinguishable particles. The identical-particle counterpart of the Schmidt basis is shown to be the single-particle basis in which the one-particle reduced density matrix is diagonal. But it does not play a special role in the issue of entanglement, which depends on the single-particle basis chosen. The nonfactorization due to (anti)symmetrization is naturally excluded by using the (anti)symmetrized basis or, equivalently, the particle number representation. The natural degrees of freedom in quantifying the identical-particle entanglement in a chosen single-particle basis are occupation numbers of different single-particle basis states. The entanglement between effectively distinguishable spins is shown to be a special case of the occupation-number entanglement

  13. Thermodynamic entanglement of magnonic condensates

    Science.gov (United States)

    Yuan, H. Y.; Yung, Man-Hong

    2018-02-01

    Over the past decade, significant progress has been achieved to create Bose-Einstein condensates (BECs) of magnetic excitations, i.e., magnons, at room temperature, which is a novel quantum many-body system with a strong spin-spin correlation, and contains potential applications in magnonic spintronics. For quantum information science, the magnonic condensates can become an attractive source of quantum entanglement, which plays a central role in most of the quantum information processing tasks. Here we theoretically study the entanglement properties of a magnon gas above and below the condensation temperature. We show that the thermodynamic entanglement of the spins is a manifestation of the off-diagonal long-range order; the entanglement of the condensate does not vanish, even if the spins are separated by an infinitely long distance, which is fundamentally distinct from the normal magnetic ordering below the Curie temperature. In addition, the phase-transition point occurs when the derivative of the entanglement changes abruptly. These results provide a theoretical foundation for a future investigation of the magnon BEC in terms of quantum entanglement.

  14. Clinical impact of renography in antenatally discovered pelviureteric stenosis: a short review of the literature; Zur klinischen Wertigkeit der Nierenfunktionsszintigraphie bei praenatal diagnostizierten renalen Abflussstoerungen

    Energy Technology Data Exchange (ETDEWEB)

    Froekiaer, J.; Eskild-Jensen, A. [Dept. of Clinical Physiology and Nuclear Medicine, Aarhus Univ. Hospital, Skejby, Aarhus (Denmark)

    2003-09-01

    Congenital unilateral hydronephrosis is a relatively frequent and often asymptomatic condition diagnosed in utero. The natural history and significance of congenital hydronephrosis on the development and long-term consequences on renal function is not sufficiently known. The present diagnostic methods do not provide prediction of the functional consequences of a potential presence of an obstruction. However, renography is an important method affecting the clinical treatment of children with prenatal unilateral hydronephrosis, and is the only method that satisfactory can provide serial accurate measurements of differential renal function. The present review briefly summarizes the clinical impact of renography in neonatally discovered hydronephrosis in relation to the pathophysiological characteristics of congenital unilateral hydronephrosis. (orig.) [German] Bei der einseitigen angeborenen Hydronephrose handelt es sich um ein relativ haeufiges Krankheitsbild, das in der Regel durch Sonographie bereits im Uterus diagnostiziert wird. Die Ursache dieser Erkrankung und ihre Bedeutung fuer die Entwicklung der Nierenfunktion im weiteren Verlauf sind nicht ausreichend bekannt. Die heute zur Verfuegung stehenden Untersuchungsmethoden koennen keine Aussage ueber die funktionellen Konsequenzen einer moeglichen Obstruktion erbringen. Die Nierenfunktionsszintigraphie ist jedoch eine sehr wichtige Methode fuer die klinische Behandlung der Kinder mit einer einseitigen praenatal diagnostizierten Hydronephrose und sie ist die einzige Methode, die wiederholte Messungen der seitengetrennten Nierenfunktion mit einer hohen Genauigkeit ermoeglicht. Die vorliegende Arbeit fasst kurz die klinische Bedeutung der Nierensequenzszintigraphie bei praenatalen Hydronephrosen zusammen und stellt einen Zusammenhang zu den pathophysiologischen Charakteristiken dieser Erkrankung her. (orig.)

  15. Crossing Boundaries in Qualitative Research – Entwurf einer empirischen Reflexivität der qualitativen Sozialforschung in Deutschland und den USA

    Directory of Open Access Journals (Sweden)

    Stephanie Bethmann

    2015-04-01

    Full Text Available Der vorliegende Beitrag widmet sich der Analyse von Prozessen der Wissenskonstruktion in der qualitativen Sozialforschung im transatlantischen Vergleich. Basierend auf explorativen Forschungsergebnissen stellen wir mit den Idealtypen engaging und observing zwei Forschungsstile vor, die sich in den Praktiken der Konstruktion von Nähe und Distanz zum Gegenstand deutlich unterscheiden. Beides, Nähe und Distanz, wird dabei nicht als innere Haltung von Forschenden oder als rigoros nationaler Stil verstanden, sondern als Produkte konkreter Arbeitspraktiken, die in Zusammenhang mit nationalen Forschungskonventionen, Rahmenbedingungen und Epistemologien stehen. Gemeinsam ist beiden Interaktionsmustern die zentrale Fundierung im amerikanischen Pragmatismus, wobei die These einer auffallend unterschiedlichen Bezugnahme auf den amerikanischen Pragmatismus in den beiden Länderkontexten diskutiert wird: Stehen in Deutschland vorwiegend dessen erkenntnistheoretische Prämissen im Mittelpunkt, sieht sich die gegenwärtige US-amerikanische Methodenlandschaft eher dessen gesellschaftspolitischen Traditionen verpflichtet. Ausgehend von diesen Beobachtungen wird abschließend die Forderung formuliert, Reflexivität in der qualitativen Sozialforschung stärker auf den Boden empirischer Analysen zu stellen. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1502191

  16. Environmental and health policies congress: Does the environment make us sick? Collection of papers; Umwelt- und gesundheitspolitischer Kongress: ``Macht uns die Umwelt krank?``. Sammlung der Vortraege

    Energy Technology Data Exchange (ETDEWEB)

    Horsch, F. [comp.] [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Projekt Umwelt und Gesundheit (PUG)

    1996-09-01

    This lecture volume on the environmental and health policies congress ``Does the environment pose health problems?``, held on 6th December 1995 in Stuttgart, compiles scientific data on the link between different diseases and environmental pollution burdens. The following individual topics are dealt with: The notion of ``risk`` in environmental medicine, cancer genesis, allergies, respiratory system diseases, fertility disorders, environment and psyche, traffic noise and risk of mycoardial infarct (VHE). [Deutsch] Der Vortragsband des umwelt- und gesundheitspolitischen Kongresses `Macht uns die Umwelt krank ?` am 06.12.1995 in Stuttgart stellt wissenschaftliche Daten fuer den Zusammenhang zwischen verschiedenen Krankheiten und Umweltbelastungen zusammen. Einzelne Themen sind : Risikobegriff der Umweltmedizin, Krebsentstehung, Allergien, Atemwegserkrankungen, Fertilitaetsstoerungen, Umwelt und Psyche, Verkehrslaerm und Herzinfarktrisiko. (VHE)

  17. Multipartite geometric entanglement in finite size XY model

    Energy Technology Data Exchange (ETDEWEB)

    Blasone, Massimo; Dell' Anno, Fabio; De Siena, Silvio; Giampaolo, Salvatore Marco; Illuminati, Fabrizio, E-mail: blasone@sa.infn.i [Dipartimento di Matematica e Informatica, Universita degli Studi di Salerno, Via Ponte don Melillo, I-84084 Fisciano (Italy)

    2009-06-01

    We investigate the behavior of the multipartite entanglement in the finite size XY model by means of the hierarchical geometric measure of entanglement. By selecting specific components of the hierarchy, we study both global entanglement and genuinely multipartite entanglement.

  18. Systematik der Fahrzeugtechnik

    Science.gov (United States)

    Burg, Heinz; Moser, Andreas

    In dem Kraftfahrtechnischen Taschenbuch, das von der Firma Robert Bosch GmbH herausgegeben wird, ist eine Gliederung der Kraftfahrzeuge vorgenommen worden, die international verbreitet und anerkannt ist. Diese Systematik ist nachstehend wiedergegeben und wird in diesem Buch weitgehend verwendet.

  19. Optimal simulation of a perfect entangler

    International Nuclear Information System (INIS)

    Yu Nengkun; Duan Runyao; Ying Mingsheng

    2010-01-01

    A 2 x 2 unitary operation is called a perfect entangler if it can generate a maximally entangled state from some unentangled input. We study the following question: How many runs of a given two-qubit entangling unitary operation are required to simulate some perfect entangler with one-qubit unitary operations as free resources? We completely solve this problem by presenting an analytical formula for the optimal number of runs of the entangling operation. Our result reveals an entanglement strength of two-qubit unitary operations.

  20. Minimal Entanglement Witness from Electrical Current Correlations.

    Science.gov (United States)

    Brange, F; Malkoc, O; Samuelsson, P

    2017-01-20

    Despite great efforts, an unambiguous demonstration of entanglement of mobile electrons in solid state conductors is still lacking. Investigating theoretically a generic entangler-detector setup, we here show that a witness of entanglement between two flying electron qubits can be constructed from only two current cross correlation measurements, for any nonzero detector efficiencies and noncollinear polarization vectors. We find that all entangled pure states, but not all mixed ones, can be detected with only two measurements, except the maximally entangled states, which require three. Moreover, detector settings for optimal entanglement witnessing are presented.

  1. Optimal entanglement witnesses for qubits and qutrits

    Science.gov (United States)

    Bertlmann, Reinhold A.; Durstberger, Katharina; Hiesmayr, Beatrix C.; Krammer, Philipp

    2005-11-01

    We study the connection between the Hilbert-Schmidt measure of entanglement (that is the minimal distance of an entangled state to the set of separable states) and entanglement witness in terms of a generalized Bell inequality which distinguishes between entangled and separable states. A method for checking the nearest separable state to a given entangled one is presented. We illustrate the general results by considering isotropic states, in particular two-qubit and two-qutrit states—and their generalizations to arbitrary dimensions—where we calculate the optimal entanglement witnesses explicitly.

  2. Optimal entanglement witnesses for qubits and qutrits

    International Nuclear Information System (INIS)

    Bertlmann, Reinhold A.; Durstberger, Katharina; Hiesmayr, Beatrix C.; Krammer, Philipp

    2005-01-01

    We study the connection between the Hilbert-Schmidt measure of entanglement (that is the minimal distance of an entangled state to the set of separable states) and entanglement witness in terms of a generalized Bell inequality which distinguishes between entangled and separable states. A method for checking the nearest separable state to a given entangled one is presented. We illustrate the general results by considering isotropic states, in particular two-qubit and two-qutrit states--and their generalizations to arbitrary dimensions--where we calculate the optimal entanglement witnesses explicitly

  3. Minimal Entanglement Witness from Electrical Current Correlations

    Science.gov (United States)

    Brange, F.; Malkoc, O.; Samuelsson, P.

    2017-01-01

    Despite great efforts, an unambiguous demonstration of entanglement of mobile electrons in solid state conductors is still lacking. Investigating theoretically a generic entangler-detector setup, we here show that a witness of entanglement between two flying electron qubits can be constructed from only two current cross correlation measurements, for any nonzero detector efficiencies and noncollinear polarization vectors. We find that all entangled pure states, but not all mixed ones, can be detected with only two measurements, except the maximally entangled states, which require three. Moreover, detector settings for optimal entanglement witnessing are presented.

  4. Deposition of radon decay products on the skin of balneotherapy patients in Gastein; Anlagerung von Radon-Folgeprodukten auf der Haut von Patienten bei der Baedertherapie in Gastein

    Energy Technology Data Exchange (ETDEWEB)

    Tempfer, H.; Schober, A.; Lettner, H.; Hofmann, W. [Inst. fuer Physik und Biophysik, Univ. Salzburg (Austria); Foisner, W. [Thermentempel Bad Hofgastein (Austria); Steger, F. [Oesterreichisches Forschungszentrum Seibersdorf GesmbH (Austria)

    2001-07-01

    ). Eine der Anwendungen des Thermalwassers ist die Exposition der Patienten in einer 450 1 fassenden Wanne (Best'sche Wanne) mit anschliessender Ruhephase. Um die Hypothese, dass die Zerfallsprodukte des Radons eine wichtige Rolle bei der therapeutischen Wirkung spielen, zu ueberpruefen, sollte das Anlagerungsverhalten der Rn-Folgeprodukte untersucht werden. Nach einem Aufenthalt der Testpersonen von 20 Minuten in der Wanne wurde der Aktivitaetsverlauf an verschiedenen Punkten des Koerpers (Unterarme, Bauch, Unterschenkel) alpha-spektrometrisch gemessen. Aus den Spektren und den Zerfallskurven koennen die Aktivitaeten der einzelnen Folgeprodukte {sup 218}Po, {sup 214}Pb und {sup 214}Bi/{sup 214}Po unterschieden werden. Um den zeitlichen Verlauf der Zerfallsproduktanlagerung zu untersuchen, wurde eine Versuchsperson dem Wasser jeweils fuer 10, 20, 30, 40 und 60 Minuten ausgesetzt; danach wurde wieder der Aktivitaetsverlauf ueber 30 Minuten aufgezeichnet. Die Messungen zeigten, dass sich die Aktivitaeten der einzelnen Zerfallsprodukte auf der Haut stark unterscheiden. Einerseits scheint die Verteilung am Koerper keineswegs homogen zu sein, andererseits konnten individuelle Unterschiede zwischen den einzelnen Person beobachtet werden. So schwankten die Mittelwerte der Aktivitaeten auf der Haut zwischen 1,2 Bq/cm{sup 2} und 4,1 Bq/cm{sup 2}. Die Exposition und Messung von Kupfer- und PVC-Platten bestaetigten fruehere Ergebnisse, nach denen sich Radonzerfallsprodukte auf unbelebten Flaechen weniger stark anlagern als auf belebten. Aus der Tatsache, dass die Zerfallsprodaktivitaeten auf der Haut bemerkenswert hoch sind, erscheint ein moeglicher Zusammenhang mit der Heilwirkung seht wahrscheinlich. (orig.)

  5. van der Waals

    Indian Academy of Sciences (India)

    University education was beyond reach for van der Waals as he had to work for earning his daily bread ... languages, which was a prerequisite for entering a University those days. van der Waals worked as a school ... take academic examinations at the University yet, van der Waals continued studying at Leiden. University ...

  6. Theorien der Videokunst

    DEFF Research Database (Denmark)

    Decker-Phillips, Edith; Lemke, Inga; Bruns, Karin

    ¨ sterreich und der Schweiz, die seit Mitte der 1980er Jahre entstanden sind und den Begriff des Mediums Video bestimmen, erweitern, die spezifische Leistung der Videokunst deuten oder ihre Systematik und Historisierung versuchen. Es finden Texte Ber¨ ucksichtigung, die den sich ver¨andernden Gebrauch des...

  7. Pathogenese der Endometriose

    OpenAIRE

    Samartzis, E P; Imesch, P; Fink, D

    2012-01-01

    Ein grundlegendes Verständnis der Pathogenese der Endometriose ist eine zwingende Voraussetzung zur Etablierung neuer und wirksamer Therapieoptionen. Dabei erscheint die Endometriose als heterogene Gruppe von Krankheitsformen, die sich unterschiedlich manifestieren. Dies erklärt, weshalb die genaue Pathogenese der Endometriose bis heute ein nicht abschliessend erforschtes Gebiet bleibt.

  8. Statistical and methodological issues in connection with the EU directive on energy end-use efficiency and energy services. Final report; Statistisch-methodische Fragen im Zusammenhang mit der Richtlinie der EU-KOM zu Endenergieeffizienz und zu Energiedienstleistungen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Eichhammer, W.; Schlomann, B.; Gruber, E.

    2006-09-15

    After its recent approval by the EU the Directive on Energy End-Use Efficiency and Energy Services entered into force on 17 May 2006. In this research project the Fraunhofer Institute ISI, acting on behalf of the German Federal Ministry for Economy and Technology, examined how this Directive might be transposed into German national law. In a first step the basic prerequisites for the Directive's transposition into national law were examined. This involved determining the national savings target for Germany as specified by the Directive and assessing its aimed-for savings in general. A question of focal interest was whether such an assessment should best be performed by a top-down or a bottom-up approach or by a combination of the two. The main characteristics of these two approaches were discussed in connection with the statistical data basis in Germany. These characteristics were then used directly for an assessment of ''Early Action'', i.e. of political measures that were implemented at an early stage (mostly after 1995) but which the Directive recognises as savings. The public sector was examined in greater depth because it has been charged with a model role by the Directive. This preparatory work provided a basis for the second step, in which a basic model for the implementation of activity assessments in Germany as required by the Directive was drafted and a possible structure for the energy efficiency action plans which the Directive requires to be set up by the member states was outlined.

  9. Detecting quantum entanglement. Entanglement witnesses and uncertainty relations

    International Nuclear Information System (INIS)

    Guehne, O.

    2004-01-01

    This thesis deals with methods of the detection of entanglement. After recalling some facts and definitions concerning entanglement and separability, we investigate two methods of the detection of entanglement. In the first part of this thesis we consider so-called entanglement witnesses, mainly in view of the detection of multipartite entanglement. Entanglement witnesses are observables for which a negative expectation value indicates entanglement. We first present a simple method to construct these witnesses. Since witnesses are nonlocal observables, they are not easy to measure in a real experiment. However, as we will show, one can circumvent this problem by decomposing the witness into several local observables which can be measured separately. We calculate the local decompositions for several interesting witnesses for two, three and four qubits. Local decompositions can be optimized in the number of measurement settings which are needed for an experimental implementation. We present a method to prove that a given local decomposition is optimal and discuss with this the optimality of our decompositions. Then we present another method of designing witnesses which are by construction measurable with local measurements. Finally, we shortly report on experiments where some of the witnesses derived in this part have been used to detect three- and four-partite entanglement of polarized photons. The second part of this thesis deals with separability criteria which are written in terms of uncertainty relations. There are two different formulations of uncertainty relations since one can measure the uncertainty of an observable by its variance as well as by entropic quantities. We show that both formulations are useful tools for the derivation of separability criteria for finite-dimensional systems and investigate the resulting criteria. Our results in this part exhibit also some more fundamental properties of entanglement: We show how known separability criteria for

  10. Entangled states in quantum mechanics

    Science.gov (United States)

    Ruža, Jānis

    2010-01-01

    In some circles of quantum physicists, a view is maintained that the nonseparability of quantum systems-i.e., the entanglement-is a characteristic feature of quantum mechanics. According to this view, the entanglement plays a crucial role in the solution of quantum measurement problem, the origin of the “classicality” from the quantum physics, the explanation of the EPR paradox by a nonlocal character of the quantum world. Besides, the entanglement is regarded as a cornerstone of such modern disciplines as quantum computation, quantum cryptography, quantum information, etc. At the same time, entangled states are well known and widely used in various physics areas. In particular, this notion is widely used in nuclear, atomic, molecular, solid state physics, in scattering and decay theories as well as in other disciplines, where one has to deal with many-body quantum systems. One of the methods, how to construct the basis states of a composite many-body quantum system, is the so-called genealogical decomposition method. Genealogical decomposition allows one to construct recurrently by particle number the basis states of a composite quantum system from the basis states of its forming subsystems. These coupled states have a structure typical for entangled states. If a composite system is stable, the internal structure of its forming basis states does not manifest itself in measurements. However, if a composite system is unstable and decays onto its forming subsystems, then the measurables are the quantum numbers, associated with these subsystems. In such a case, the entangled state has a dynamical origin, determined by the Hamiltonian of the corresponding decay process. Possible correlations between the quantum numbers of resulting subsystems are determined by the symmetries-conservation laws of corresponding dynamical variables, and not by the quantum entanglement feature.

  11. Der II. Hauptsatz der Wärmelehre

    Science.gov (United States)

    Heintze, Joachim

    Wir haben in (4.44) den II. Hauptsatz als empirische Tatsache folgendermaßen formuliert: (i) Wärmeenergie geht von selbst nur von einem wärmeren Körper auf einen kälteren über, niemals in der umgekehrten Richtung. Nun werden wir beweisen, dass sich aus diesem Prinzip folgende äquivalente Formulierungen für den II. Hauptsatz ableiten lassen: (ii) Es ist unmöglich, ein Perpetuum mobile zweiter Art zu bauen, d. h. eine Maschine, die fortlaufend Wärmeenergie vollständig in mechanische Arbeit umsetzen kann. Eine Wärmekraftmaschine, die einen Kreisprozess mit der höchsten Temperatur Tw und der niedrigsten Temperatur Tk durchläuft, hat höchstens den Carnotschen Wirkungsgrad c = (Tw - Tk)/Tw. Wenn in der Maschine nur reversible Prozesse ablaufen, die gesamte Wärmezufuhr bei der Temperatur Tw erfolgt und ausschließlich bei der Temperatur Tw gekühlt wird, ist ihr Wirkungsgrad = C. Es gibt keine Wärmekraftmaschine, die eine bessere Ausnutzung der Wärmeenergie ermöglicht. (iv) In jedem thermodynamischen System existiert die Zustandsgröße Entropie, definiert durch ihr Differential dS = (dQrev)/T . Entropie kann erzeugt, aber nicht vernichtet werden. Bei Zustandsänderungen, die in einem abgeschlossenen System ablaufen, nimmt die Entropie entweder zu (irreversible Prozesse), oder sie bleibt konstant (reversible Prozesse). Im Anschluss an (iii) werden wir zur Definition der thermodynamischen Temperatur und bei der Diskussion von (iv) zu einem tieferen Verständnis der Entropie gelangen. Es zeigt sich, dass die Entropie das eigentliche Bindeglied zwischen Mechanik und Wärmelehre darstellt. Am Ende des Kapitels werden wir einige Anwendungen des II. Hauptsatzes betrachten.

  12. Entangled spin chain

    Science.gov (United States)

    Salberger, Olof; Korepin, Vladimir

    We introduce a new model of interacting spin 1/2. It describes interactions of three nearest neighbors. The Hamiltonian can be expressed in terms of Fredkin gates. The Fredkin gate (also known as the controlled swap gate) is a computational circuit suitable for reversible computing. Our construction generalizes the model presented by Peter Shor and Ramis Movassagh to half-integer spins. Our model can be solved by means of Catalan combinatorics in the form of random walks on the upper half plane of a square lattice (Dyck walks). Each Dyck path can be mapped on a wave function of spins. The ground state is an equally weighted superposition of Dyck walks (instead of Motzkin walks). We can also express it as a matrix product state. We further construct a model of interacting spins 3/2 and greater half-integer spins. The models with higher spins require coloring of Dyck walks. We construct a SU(k) symmetric model (where k is the number of colors). The leading term of the entanglement entropy is then proportional to the square root of the length of the lattice (like in the Shor-Movassagh model). The gap closes as a high power of the length of the lattice [5, 11].

  13. Teleportation of N-particle entangled W state via entanglement swapping

    Institute of Scientific and Technical Information of China (English)

    Zhan You-Bang

    2004-01-01

    A scheme for teleporting an unknown N-particle entangled W state is proposed via entanglement swapping. In this scheme, N maximally entangled particle pairs are used as quantum channel. As a special case, the teleportation of an unknown four-particle entangled W state is studied.

  14. Frauenforschung in der Behindertenpädagogik Women’s Studies in Educational Work With the Disabled

    Directory of Open Access Journals (Sweden)

    Ute Weinmann

    2001-03-01

    Full Text Available Mit dem von der Dortmunder Professorin Ulrike Schildmann und der wissenschaftlichen Mitarbeiterin Bettina Bretländer herausgegebenen Band „Frauenforschung in der Behindertenpädagogik“ wird bewußt ein als Arbeitsbuch (S. 7 konzipiertes Werk vorgelegt nicht nur für Studentinnen und Studenten, sondern auch für alle anderen an diesen Fragen Interessierten. Dieser in der Einleitung formulierten Intention folgend, werden fachdiskursive und auf unterschiedlichen Bearbeitungsniveaus angesiedelte Beiträge präsentiert, die Leserinnen und Leser dazu einladen sollen, „sich intensiver mit den vielfältigen Fragestellungen des Zusammenhangs von Behinderung und Geschlecht auseinander zu setzen“ (S. 7.The book, “Women’s Studies in Educational Work With the Disabled”, edited by the Dortmund professor Ulrike Schildmann and the member of academic staff Bettina Bretländer, is consciously meant to be a a book to work with. It addresses not only students but everyone interested in the questions it deals with. Following this intention, outlined in the introduction, various contributions are being presented, which are meant to invite readers to deal with the complex questions of disability and gender in a more intensive way.

  15. Protecting single-photon entanglement with practical entanglement source

    Science.gov (United States)

    Zhou, Lan; Ou-Yang, Yang; Wang, Lei; Sheng, Yu-Bo

    2017-06-01

    Single-photon entanglement (SPE) is important for quantum communication and quantum information processing. However, SPE is sensitive to photon loss. In this paper, we discuss a linear optical amplification protocol for protecting SPE. Different from the previous protocols, we exploit the practical spontaneous parametric down-conversion (SPDC) source to realize the amplification, for the ideal entanglement source is unavailable in current quantum technology. Moreover, we prove that the amplification using the entanglement generated from SPDC source as auxiliary is better than the amplification assisted with single photons. The reason is that the vacuum state from SPDC source will not affect the amplification, so that it can be eliminated automatically. This protocol may be useful in future long-distance quantum communications.

  16. From entanglement witness to generalized Catalan numbers

    Science.gov (United States)

    Cohen, E.; Hansen, T.; Itzhaki, N.

    2016-07-01

    Being extremely important resources in quantum information and computation, it is vital to efficiently detect and properly characterize entangled states. We analyze in this work the problem of entanglement detection for arbitrary spin systems. It is demonstrated how a single measurement of the squared total spin can probabilistically discern separable from entangled many-particle states. For achieving this goal, we construct a tripartite analogy between the degeneracy of entanglement witness eigenstates, tensor products of SO(3) representations and classical lattice walks with special constraints. Within this framework, degeneracies are naturally given by generalized Catalan numbers and determine the fraction of states that are decidedly entangled and also known to be somewhat protected against decoherence. In addition, we introduce the concept of a “sterile entanglement witness”, which for large enough systems detects entanglement without affecting much the system’s state. We discuss when our proposed entanglement witness can be regarded as a sterile one.

  17. Experimental distribution of entanglement with separable carriers

    Science.gov (United States)

    Fedrizzi, Alessandro; Zuppardo, Margherita; Gillett, Geoff; Broome, Matthew; de Almeida, Marcelo; Paternostro, Mauro; White, Andrew; Paterek, Tomasz

    2014-03-01

    Quantum networks will allow us to overcome distance limitations in quantum communication, and to share quantum computing tasks between remote quantum processors. The key requirement for quantum networking is the distribution of entanglement between nodes. Surprisingly, entanglement can be generated across a network without directly being communicated between nodes. In contrast to information gain, which cannot exceed the communicated information, the entanglement gain is bounded by the communicated quantum discord, a more general measure of quantum correlation that includes but is not limited to entanglement. Here we report an experiment in which two communicating parties who share three initially separable photonic qubits are entangled by exchange of a carrier photon that is not entangled with either party at all times. We show that distributing entanglement with separable carriers is resilient to noise and in some cases becomes the only way of distributing entanglement over noisy environments.

  18. Separability criteria for genuine multiparticle entanglement

    NARCIS (Netherlands)

    Guhne, O.; Seevinck, M.P.|info:eu-repo/dai/nl/304847399

    2010-01-01

    We present a method to derive separability criteria for different classes of multiparticle entanglement, especially genuine multiparticle entanglement. The resulting criteria are necessary and sufficient for certain families of states. This, for example, completely solves the problem of classifying

  19. Separability Criteria for Genuine Multiparticle Entanglement

    NARCIS (Netherlands)

    Guehne, O.; Seevinck, M.P.

    2010-01-01

    We present a method to derive separability criteria for different classes of multiparticle entanglement, especially genuine multiparticle entanglement. The resulting criteria are necessary and sufficient for certain families of states. This, for example, completely solves the problem of classifying

  20. HMSRP Hawaiian Monk Seal Entanglement data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data set contains records of all entanglements of Hawaiian monk seals in marine debris. The data set comprises records of seals entangled by derelict fishing...

  1. Relay entanglement and clusters of correlated spins

    Science.gov (United States)

    Doronin, S. I.; Zenchuk, A. I.

    2018-06-01

    Considering a spin-1/2 chain, we suppose that the entanglement passes from a given pair of particles to another one, thus establishing the relay transfer of entanglement along the chain. Therefore, we introduce the relay entanglement as a sum of all pairwise entanglements in a spin chain. For more detailed studying the effects of remote pairwise entanglements, we use the partial sums collecting entanglements between the spins separated by up to a certain number of nodes. The problem of entangled cluster formation is considered, and the geometric mean entanglement is introduced as a characteristic of quantum correlations in a cluster. Generally, the lifetime of a cluster decreases with an increase in its size.

  2. Entanglement properties between two atoms in the binomial optical field interacting with two entangled atoms

    International Nuclear Information System (INIS)

    Liu Tang-Kun; Zhang Kang-Long; Tao Yu; Shan Chuan-Jia; Liu Ji-Bing

    2016-01-01

    The temporal evolution of the degree of entanglement between two atoms in a system of the binomial optical field interacting with two arbitrary entangled atoms is investigated. The influence of the strength of the dipole–dipole interaction between two atoms, probabilities of the Bernoulli trial, and particle number of the binomial optical field on the temporal evolution of the atomic entanglement are discussed. The result shows that the two atoms are always in the entanglement state. Moreover, if and only if the two atoms are initially in the maximally entangled state, the entanglement evolution is not affected by the parameters, and the degree of entanglement is always kept as 1. (paper)

  3. Quantum entanglement and special relativity

    International Nuclear Information System (INIS)

    Nishikawa, Yoshihisa

    2008-01-01

    Quantum entanglement was suggested by Einstein to indicate that quantum mechanics was incomplete. However, against Einstein's expectation, the phenomenon due to quantum entanglement has been verified by experiments. Recently, in quantum information theory, it has been also treated as a resource for quantum teleportation and so on. In around 2000, it is recognized that quantum correlations between two particles of one pair state in an entangled spin-state are affected by the non-trivial effect due to the successive Lorentz transformation. This relativistic effect is called the Wigner rotation. The Wigner rotation has to been taken into account when we observe spin-correlation of moving particles in a different coordinate frame. In this paper, first, we explain quantum entanglement and its modification due to the Wigner rotation. After that, we introduce an extended model instead of one pair state model. In the extended model, quantum entanglement state is prepared as a superposition state of various pair states. We have computed the von Neumann entropy and the Shannon entropy to see the global behavior of variation for the spin correlation due to the relativistic effect. We also discuss distinguishability between the two particles of the pair. (author)

  4. Quantum walks with entangled coins

    International Nuclear Information System (INIS)

    Venegas-Andraca, S E; Ball, J L; Burnett, K; Bose, S

    2005-01-01

    We present a mathematical formalism for the description of un- restricted quantum walks with entangled coins and one walker. The numerical behaviour of such walks is examined when using a Bell state as the initial coin state, with two different coin operators, two different shift operators, and one walker. We compare and contrast the performance of these quantum walks with that of a classical random walk consisting of one walker and two maximally correlated coins as well as quantum walks with coins sharing different degrees of entanglement. We illustrate that the behaviour of our walk with entangled coins can be very different in comparison to the usual quantum walk with a single coin. We also demonstrate that simply by changing the shift operator, we can generate widely different distributions. We also compare the behaviour of quantum walks with maximally entangled coins with that of quantum walks with non-entangled coins. Finally, we show that the use of different shift operators on two and three qubit coins leads to different position probability distributions in one- and two-dimensional graphs

  5. Communication cost of entanglement transformations

    International Nuclear Information System (INIS)

    Hayden, Patrick; Winter, Andreas

    2003-01-01

    We study the amount of communication needed for two parties to transform some given joint pure state into another one, either exactly or with some fidelity. Specifically, we present a method to lower bound this communication cost even when the amount of entanglement does not increase. Moreover, the bound applies even if the initial state is supplemented with unlimited entanglement in the form of EPR (Einstein-Podolsky-Rosen) pairs and the communication is allowed to be quantum mechanical. We then apply the method to the determination of the communication cost of asymptotic entanglement concentration and dilution. While concentration is known to require no communication whatsoever, the best known protocol for dilution, discovered by H.-K. Lo and S. Popescu [Phys. Rev. Lett. 83, 1459 (1999)], requires exchange of a number of bits that is of the order of the square root of the number of EPR pairs. Here we prove a matching lower bound of the same asymptotic order, demonstrating the optimality of the Lo-Popescu protocol up to a constant factor and establishing the existence of a fundamental asymmetry between the concentration and dilution tasks. We also discuss states for which the minimal communication cost is proportional to their entanglement, such as the states recently introduced in the context of 'embezzling entanglement' (W. van Dam and P. Hayden, e-print quant-ph/0201041)

  6. Entanglement in mutually unbiased bases

    Energy Technology Data Exchange (ETDEWEB)

    Wiesniak, M; Zeilinger, A [Vienna Center for Quantum Science and Technology (VCQ), Faculty of Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna (Austria); Paterek, T, E-mail: tomasz.paterek@nus.edu.sg [Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 Singapore (Singapore)

    2011-05-15

    One of the essential features of quantum mechanics is that most pairs of observables cannot be measured simultaneously. This phenomenon manifests itself most strongly when observables are related to mutually unbiased bases. In this paper, we shed some light on the connection between mutually unbiased bases and another essential feature of quantum mechanics, quantum entanglement. It is shown that a complete set of mutually unbiased bases of a bipartite system contains a fixed amount of entanglement, independent of the choice of the set. This has implications for entanglement distribution among the states of a complete set. In prime-squared dimensions we present an explicit experiment-friendly construction of a complete set with a particularly simple entanglement distribution. Finally, we describe the basic properties of mutually unbiased bases composed of product states only. The constructions are illustrated with explicit examples in low dimensions. We believe that the properties of entanglement in mutually unbiased bases may be one of the ingredients to be taken into account to settle the question of the existence of complete sets. We also expect that they will be relevant to applications of bases in the experimental realization of quantum protocols in higher-dimensional Hilbert spaces.

  7. Energy entanglement relation for quantum energy teleportation

    Energy Technology Data Exchange (ETDEWEB)

    Hotta, Masahiro, E-mail: hotta@tuhep.phys.tohoku.ac.j [Department of Physics, Faculty of Science, Tohoku University, Sendai 980-8578 (Japan)

    2010-07-26

    Protocols of quantum energy teleportation (QET), while retaining causality and local energy conservation, enable the transportation of energy from a subsystem of a many-body quantum system to a distant subsystem by local operations and classical communication through ground-state entanglement. We prove two energy-entanglement inequalities for a minimal QET model. These relations help us to gain a profound understanding of entanglement itself as a physical resource by relating entanglement to energy as an evident physical resource.

  8. Minimal Entanglement Witness From Electrical Current Correlations

    OpenAIRE

    Brange, F.; Malkoc, O.; Samuelsson, P.

    2016-01-01

    Despite great efforts, an unambiguous demonstration of entanglement of mobile electrons in solid state conductors is still lacking. Investigating theoretically a generic entangler-detector setup, we here show that a witness of entanglement between two flying electron qubits can be constructed from only two current cross correlation measurements, for any nonzero detector efficiencies and non-collinear polarization vectors. We find that all entangled pure states, but not all mixed ones, can be ...

  9. Functional MR imaging of the liver; Funktionelle MR-Tomographie der Leber

    Energy Technology Data Exchange (ETDEWEB)

    Wibmer, A.; Nolz, R.; Ba-Ssalamah, A. [Medizinische Universitaet Wien, Allgemeines Krankenhaus der Stadt Wien, Universitaetsklinik fuer Radiodiagnostik und Nuklearmedizin, Wien (Austria); Trauner, M. [Medizinische Universitaet Wien, Universitaetsklinik fuer Innere Medizin III, Klinische Abteilung fuer Gastroenterologie und Hepatologie, Wien (Austria)

    2015-12-15

    Hypertension oder eine eingeschraenkte Organfunktion, koennen mithilfe spezieller MRT-Techniken entdeckt und quantifiziert werden. Die vorliegende Arbeit bietet einen Ueberblick ueber die dabei angewendeten Methoden und diskutiert die Wertigkeit der funktionellen Leber-MRT im klinischen Zusammenhang. (orig.)

  10. The minimal entanglement of bipartite decompositions as a witness of strong entanglement in a quantum system

    OpenAIRE

    Zenchuk, A. I.

    2010-01-01

    We {characterize the multipartite entanglement in a quantum system by the quantity} which vanishes if only the quantum system may be decomposed into two weakly entangled subsystems, unlike measures of multipartite entanglement introduced before. We refer to this {quantity} as the minimal entanglement of bipartite decompositions (MEBD). Big MEBD means that the system may not be decomposed into two weakly entangled subsystems. MEBD allows one to define, for instance, whether the given quantum s...

  11. Comparison Re-invented: Adaptation of Universal Methods to African Studies (Conference Report Die Wiederentdeckung des Vergleichs: Zur Anwendung universeller Methoden in der Afrikaforschung (Konferenzbericht

    Directory of Open Access Journals (Sweden)

    Franzisca Zanker

    2013-01-01

    Full Text Available Drawing from a combination of specific, empirical research projects with different theoretical backgrounds, a workshop discussed one methodological aspect often somewhat overlooked in African Studies: comparison. Participants addressed several questions, along with presenting overviews of how different disciplines within African Studies approach comparison in their research and naming specific challenges within individual research projects. The questions examined included: Why is explicit comparative research so rare in African Studies? Is comparative research more difficult in the African context than in other regions? Does it benefit our research? Should scholars strive to generalise beyond individual cases? Do studies in our field require an explicit comparative design, or will implicit comparison suffice? Cross-discipline communication should help us to move forward in this methodological debate, though in the end the subject matter and specific research question will lead to the appropriate comparative approach, not the other way round.Mit Blick auf einige empirische Forschungsprojekte mit jeweils unterschiedlichem theoretischem Hintergrund wurde im Rahmen eines Workshops ein methodologischer Aspekt debattiert, der in der Afrikaforschung wenig Beachtung erfährt: der Vergleich. Die Teilnehmer(innen entwickelten Fragestellungen, stellten jeweils dar, inwieweit in den verschiedene Disziplinen der Afrikaforschung der Vergleich als Methode eingesetzt wird, und benannten spezifische Herausforderungen in diesem Zusammenhang für einzelne Forschungsprojekte. Unter anderem wurden folgende Fragen erörtert: Warum ist die explizit vergleichende Methode in der Afrikaforschung so selten? Ist vergleichende Forschung im Kontext Afrikas schwieriger anwendbar als in der Forschung zu anderen Regionen? Verbessert sie unsere Forschungsresultate? Sollten sich Forscher um Generalisierungen jenseits der Einzelfallstudien bemühen? Ist in der Afrikaforschung eine

  12. Entropy-driven phase transitions of entanglement

    Science.gov (United States)

    Facchi, Paolo; Florio, Giuseppe; Parisi, Giorgio; Pascazio, Saverio; Yuasa, Kazuya

    2013-05-01

    We study the behavior of bipartite entanglement at fixed von Neumann entropy. We look at the distribution of the entanglement spectrum, that is, the eigenvalues of the reduced density matrix of a quantum system in a pure state. We report the presence of two continuous phase transitions, characterized by different entanglement spectra, which are deformations of classical eigenvalue distributions.

  13. Maximally Entangled Multipartite States: A Brief Survey

    International Nuclear Information System (INIS)

    Enríquez, M; Wintrowicz, I; Życzkowski, K

    2016-01-01

    The problem of identifying maximally entangled quantum states of a composite quantum systems is analyzed. We review some states of multipartite systems distinguished with respect to certain measures of quantum entanglement. Numerical results obtained for 4-qubit pure states illustrate the fact that the notion of maximally entangled state depends on the measure used. (paper)

  14. Quantum entanglement and quantum computational algorithms

    Indian Academy of Sciences (India)

    Abstract. The existence of entangled quantum states gives extra power to quantum computers over their classical counterparts. Quantum entanglement shows up qualitatively at the level of two qubits. We demonstrate that the one- and the two-bit Deutsch-Jozsa algorithm does not require entanglement and can be mapped ...

  15. Universal distortion-free entanglement concentration

    International Nuclear Information System (INIS)

    Matsumoto, Keiji; Hayashi, Masahito

    2007-01-01

    We propose a new protocol of universal entanglement concentration, which converts many copies of an unknown pure state to an exact maximally entangled state. The yield of the protocol, which is outputted as a classical information, is probabilistic, and achieves the entropy rate with high probability, just as nonuniversal entanglement concentration protocols do

  16. Quantum teleportation of entangled squeezed vacuum states

    Institute of Scientific and Technical Information of China (English)

    蔡新华

    2003-01-01

    An optical scheme for probabilistic teleporting entangled squeezed vacuum states (SVS) is proposed. In this scheme,the teleported state is a bipartite entangled SVS,and the quantum channel is a tripartite entangled SVS.The process of the teleportation is achieved by using a 50/50 symmetric beamsplitter and photon detectors with the help of classical information.

  17. Structural entanglements in protein complexes

    Science.gov (United States)

    Zhao, Yani; Chwastyk, Mateusz; Cieplak, Marek

    2017-06-01

    We consider multi-chain protein native structures and propose a criterion that determines whether two chains in the system are entangled or not. The criterion is based on the behavior observed by pulling at both termini of each chain simultaneously in the two chains. We have identified about 900 entangled systems in the Protein Data Bank and provided a more detailed analysis for several of them. We argue that entanglement enhances the thermodynamic stability of the system but it may have other functions: burying the hydrophobic residues at the interface and increasing the DNA or RNA binding area. We also study the folding and stretching properties of the knotted dimeric proteins MJ0366, YibK, and bacteriophytochrome. These proteins have been studied theoretically in their monomeric versions so far. The dimers are seen to separate on stretching through the tensile mechanism and the characteristic unraveling force depends on the pulling direction.

  18. Entanglement in open quantum systems

    International Nuclear Information System (INIS)

    Isar, A.

    2007-01-01

    In the framework of the theory of open systems based on quantum dynamical semigroups, we solve the master equation for two independent bosonic oscillators interacting with an environment in the asymptotic long-time regime. We give a description of the continuous-variable entanglement in terms of the covariance matrix of the quantum states of the considered system for an arbitrary Gaussian input state. Using the Peres-Simon necessary and sufficient condition for separability of two-mode Gaussian states, we show that the two non-interacting systems immersed in a common environment and evolving under a Markovian, completely positive dynamics become asymptotically entangled for certain environments, so that their non-local quantum correlations exist in the long-time regime. (author) Key words: quantum information theory, open systems, quantum entanglement, inseparable states

  19. Global entanglement in XXZ chains

    International Nuclear Information System (INIS)

    Canosa, N.; Rossignoli, R.

    2006-01-01

    We examine the thermal entanglement of XXZ-type Heisenberg chains in the presence of a uniform magnetic field along the z axes through the evaluation of the negativity associated with bipartitions of the whole system and subsystems. Limit temperatures for nonzero global negativities are shown to depend on the asymmetry Δ, but not on the uniform field, and can be much higher than those limiting pairwise entanglement. It is also shown that global bipartite entanglement may exist for T>0 even for Δ≥1, i.e., when the system is fully aligned (and hence separable) at T=0, and that the bipartition leading to the highest limit temperature depends on Δ

  20. Measuring coherence with entanglement concurrence

    Science.gov (United States)

    Qi, Xianfei; Gao, Ting; Yan, Fengli

    2017-07-01

    Quantum coherence is a fundamental manifestation of the quantum superposition principle. Recently, Baumgratz et al (2014 Phys. Rev. Lett. 113 140401) presented a rigorous framework to quantify coherence from the view of theory of physical resource. Here we propose a new valid quantum coherence measure which is a convex roof measure, for a quantum system of arbitrary dimension, essentially using the generalized Gell-Mann matrices. Rigorous proof shows that the proposed coherence measure, coherence concurrence, fulfills all the requirements dictated by the resource theory of quantum coherence measures. Moreover, strong links between the resource frameworks of coherence concurrence and entanglement concurrence is derived, which shows that any degree of coherence with respect to some reference basis can be converted to entanglement via incoherent operations. Our work provides a clear quantitative and operational connection between coherence and entanglement based on two kinds of concurrence. This new coherence measure, coherence concurrence, may also be beneficial to the study of quantum coherence.

  1. Berry phase in entangled systems

    International Nuclear Information System (INIS)

    Bertlmann, R.A.; Hasegawa, Y.; Hiesmayr, B.C.; Durstberger, C.

    2005-01-01

    Full text: The influence of the geometric phase, in particular the Berry phase, on an entangled spin-1/2 system is studied. We discuss in detail the case, where the geometric phase is generated only by one part of the Hilbert space. We are able to cancel the effects of the dynamical phase by using the 'spin-echo' method. We analyze how the Berry phase affects the Bell angles and the maximal violation of a CHSH-Bell inequality. Furthermore, we suggest an experimental realization of our setup within neutron interferometry. It is possible to create entanglement between different degrees of freedom (spin and spatial degree of freedom) for a single neutron. The influence of the geometrical phase on the entangled neutron state is tested experimentally which is work in progress. (author)

  2. Quantum Entanglements: Selected Papers

    International Nuclear Information System (INIS)

    Giannetto, E

    2005-01-01

    This book is a sort of tribute to Rob Clifton (1964-2002), Associate Professor of Philosophy and Associate Director of the Center for Philosophy of Science at the University of Pittsburgh, philosopher of physics and editor of the journal Studies in the History and Philosophy of Modern Physics, who tragically died of cancer. It contains fourteen papers by Clifton, for the most part written in collaboration with other authors (Jeffrey Bub (2), Sheldon Goldstein, Michael Dickson, Hans Halvorson (6), Adrian Kent (2)), published between 1995 and 2002. The choice of papers made by the editors is very impressive. They concern the foundations of quantum mechanics and quantum field theory. Among the issues discussed are the modal interpretations of quantum mechanics, the problems of hidden variables theories, non-locality, Bell's inequality, the Einstein-Podolsky-Rosen paradox, Lorentz invariance, de-coherence, non-contextuality, complementarity, entanglement and quantum information. A consequence of such investigations is that non-separability is a more complex issue than violation of Bell's inequality. Apart from the perspective one can follow-whether one agrees or not with Clifton-these papers are effective contributions to an understanding of the problems involved in the foundations of quantum mechanics. The most interesting parts, in my opinion, are related to the extension of the discussion of foundational problems to quantum field theory: on the algebraic approach, and on the twin concepts of particle and vacuum. Non-locality appears to be 'worse' in relativistic quantum field theory than in non-relativistic quantum mechanics. All the papers deal with relevant epistemological and even historical aspects of quantum mechanics interpretations, but all the issues are discussed from a technical, logical and mathematical approach. A complete bibliography of Clifton's papers is given at the end of the volume. (book review)

  3. Entanglement evolution for quantum trajectories

    International Nuclear Information System (INIS)

    Vogelsberger, S; Spehner, D

    2011-01-01

    Entanglement is a key resource in quantum information. It can be destroyed or sometimes created by interactions with a reservoir. In recent years, much attention has been devoted to the phenomena of entanglement sudden death and sudden birth, i.e., the sudden disappearance or revival of entanglement at finite times resulting from a coupling of the quantum system to its environment. We investigate the evolution of the entanglement of noninteracting qubits coupled to reservoirs under monitoring of the reservoirs by means of continuous measurements. Because of these measurements, the qubits remain at all times in a pure state, which evolves randomly. To each measurement result (or 'realization') corresponds a quantum trajectory in the Hilbert space of the qubits. We show that for two qubits coupled to independent baths subjected to local measurements, the average of the qubits' concurrence over all quantum trajectories is either constant or decays exponentially. The corresponding decay rate depends on the measurement scheme only. This result contrasts with the entanglement sudden death phenomenon exhibited by the qubits' density matrix in the absence of measurements. Our analysis applies to arbitrary quantum jump dynamics (photon counting) as well as to quantum state diffusion (homodyne or heterodyne detections) in the Markov limit. We discuss the best measurement schemes to protect the entanglement of the qubits. We also analyze the case of two qubits coupled to a common bath. Then, the average concurrence can vanish at discrete times and may coincide with the concurrence of the density matrix. The results explained in this article have been presented during the 'Fifth International Workshop DICE2010' by the first author and have been the subject of a prior publication.

  4. Bosonic behavior of entangled fermions

    DEFF Research Database (Denmark)

    C. Tichy, Malte; Alexander Bouvrie, Peter; Mølmer, Klaus

    2012-01-01

    Two bound, entangled fermions form a composite boson, which can be treated as an elementary boson as long as the Pauli principle does not affect the behavior of many such composite bosons. The departure of ideal bosonic behavior is quantified by the normalization ratio of multi-composite-boson st......Two bound, entangled fermions form a composite boson, which can be treated as an elementary boson as long as the Pauli principle does not affect the behavior of many such composite bosons. The departure of ideal bosonic behavior is quantified by the normalization ratio of multi...

  5. Deterministic chaos in entangled eigenstates

    Science.gov (United States)

    Schlegel, K. G.; Förster, S.

    2008-05-01

    We investigate the problem of deterministic chaos in connection with entangled states using the Bohmian formulation of quantum mechanics. We show for a two particle system in a harmonic oscillator potential, that in a case of entanglement and three energy eigen-values the maximum Lyapunov-parameters of a representative ensemble of trajectories for large times develops to a narrow positive distribution, which indicates nearly complete chaotic dynamics. We also present in short results from two time-dependent systems, the anisotropic and the Rabi oscillator.

  6. Deterministic chaos in entangled eigenstates

    Energy Technology Data Exchange (ETDEWEB)

    Schlegel, K.G. [Fakultaet fuer Physik, Universitaet Bielefeld, Postfach 100131, D-33501 Bielefeld (Germany)], E-mail: guenter.schlegel@arcor.de; Foerster, S. [Fakultaet fuer Physik, Universitaet Bielefeld, Postfach 100131, D-33501 Bielefeld (Germany)

    2008-05-12

    We investigate the problem of deterministic chaos in connection with entangled states using the Bohmian formulation of quantum mechanics. We show for a two particle system in a harmonic oscillator potential, that in a case of entanglement and three energy eigen-values the maximum Lyapunov-parameters of a representative ensemble of trajectories for large times develops to a narrow positive distribution, which indicates nearly complete chaotic dynamics. We also present in short results from two time-dependent systems, the anisotropic and the Rabi oscillator.

  7. Deterministic chaos in entangled eigenstates

    International Nuclear Information System (INIS)

    Schlegel, K.G.; Foerster, S.

    2008-01-01

    We investigate the problem of deterministic chaos in connection with entangled states using the Bohmian formulation of quantum mechanics. We show for a two particle system in a harmonic oscillator potential, that in a case of entanglement and three energy eigen-values the maximum Lyapunov-parameters of a representative ensemble of trajectories for large times develops to a narrow positive distribution, which indicates nearly complete chaotic dynamics. We also present in short results from two time-dependent systems, the anisotropic and the Rabi oscillator

  8. Quantum entanglement: theory and applications

    Energy Technology Data Exchange (ETDEWEB)

    Schuch, N.

    2007-10-10

    This thesis deals with various questions concerning the quantification, the creation, and the application of quantum entanglement. Entanglement arises due to the restriction to local operations and classical communication. We investigate how the notion of entanglement changes if additional restrictions in form of a superselection rule are imposed and show that they give rise to a new resource. We characterize this resource and demonstrate that it can be used to overcome the restrictions, very much as entanglement can overcome the restriction to local operations by teleportation. We next turn towards the optimal generation of resources. We show how squeezing can be generated as efficiently as possible from noisy squeezing operations supplemented by noiseless passive operations, and discuss the implications of this result to the optimal generation of entanglement. The difficulty in describing the behaviour of correlated quantum many-body systems is ultimately due to the complicated entanglement structure of multipartite states. Using quantum information techniques, we investigate the ground state properties of lattices of harmonic oscillators. We derive an exponential decay of correlations for gapped systems, compute the dependence of correlation length and gap, and investigate the notion of criticality by relating a vanishing energy gap to an algebraic decay of correlations. Recently, ideas from entanglement theory have been applied to the description of many-body systems. Matrix Product States (MPS), which have a particularly simple interpretation from the point of quantum information, perform extremely well in approximating the ground states of local Hamiltonians. It is generally believed that this is due to the fact that both ground states and MPS obey an entropic area law. We clarify the relation between entropy scaling laws and approximability by MPS, and in particular find that an area law does not necessarily imply approximability. Using the quantum

  9. Quantum entanglement: theory and applications

    International Nuclear Information System (INIS)

    Schuch, N.

    2007-01-01

    This thesis deals with various questions concerning the quantification, the creation, and the application of quantum entanglement. Entanglement arises due to the restriction to local operations and classical communication. We investigate how the notion of entanglement changes if additional restrictions in form of a superselection rule are imposed and show that they give rise to a new resource. We characterize this resource and demonstrate that it can be used to overcome the restrictions, very much as entanglement can overcome the restriction to local operations by teleportation. We next turn towards the optimal generation of resources. We show how squeezing can be generated as efficiently as possible from noisy squeezing operations supplemented by noiseless passive operations, and discuss the implications of this result to the optimal generation of entanglement. The difficulty in describing the behaviour of correlated quantum many-body systems is ultimately due to the complicated entanglement structure of multipartite states. Using quantum information techniques, we investigate the ground state properties of lattices of harmonic oscillators. We derive an exponential decay of correlations for gapped systems, compute the dependence of correlation length and gap, and investigate the notion of criticality by relating a vanishing energy gap to an algebraic decay of correlations. Recently, ideas from entanglement theory have been applied to the description of many-body systems. Matrix Product States (MPS), which have a particularly simple interpretation from the point of quantum information, perform extremely well in approximating the ground states of local Hamiltonians. It is generally believed that this is due to the fact that both ground states and MPS obey an entropic area law. We clarify the relation between entropy scaling laws and approximability by MPS, and in particular find that an area law does not necessarily imply approximability. Using the quantum

  10. Critical metals in the great transformation; Kritische Metalle in der Grossen Transformation

    Energy Technology Data Exchange (ETDEWEB)

    Exner, Andreas; Held, Martin; Kuemmerer, Klaus (eds.)

    2016-07-01

    Tiefsee gewinnen laesst. Kritische Metalle werden in den uebergreifenden Zusammenhang der anstehenden Grossen Transformation eingeordnet. Das Buch beleuchtet insbesondere die grundlegende Bedeutung der stofflichen Voraussetzungen der Energiewende und die energetischen Voraussetzungen der Stoffwende wie auch der Digitalisierung. Damit laesst sich zeigen, dass nicht nur seltene Erden kritisch sind, sondern ebenso Industriemetalle wie etwa Kupfer. Ressourcenpolitik zielt unter anderem auf Sicherung der Primaerversorgung mit Technologiemetallen, auf Ressourceneffizienz, Recycling und Substitution kritischer Stoffe. Trotz erster Erfolge ist die Dynamik in Richtung einer zunehmenden Dissipation wertvoller kritischer Metalle ungebrochen. Noetig ist eine rasche Umsteuerung mit dem Ziel, kritische Metalle nicht laenger im grossen Stil zu verbrauchen, sondern sie klug zu gebrauchen.

  11. Benchmarks and statistics of entanglement dynamics

    International Nuclear Information System (INIS)

    Tiersch, Markus

    2009-01-01

    In the present thesis we investigate how the quantum entanglement of multicomponent systems evolves under realistic conditions. More specifically, we focus on open quantum systems coupled to the (uncontrolled) degrees of freedom of an environment. We identify key quantities that describe the entanglement dynamics, and provide efficient tools for its calculation. For quantum systems of high dimension, entanglement dynamics can be characterized with high precision. In the first part of this work, we derive evolution equations for entanglement. These formulas determine the entanglement after a given time in terms of a product of two distinct quantities: the initial amount of entanglement and a factor that merely contains the parameters that characterize the dynamics. The latter is given by the entanglement evolution of an initially maximally entangled state. A maximally entangled state thus benchmarks the dynamics, and hence allows for the immediate calculation or - under more general conditions - estimation of the change in entanglement. Thereafter, a statistical analysis supports that the derived (in-)equalities describe the entanglement dynamics of the majority of weakly mixed and thus experimentally highly relevant states with high precision. The second part of this work approaches entanglement dynamics from a topological perspective. This allows for a quantitative description with a minimum amount of assumptions about Hilbert space (sub-)structure and environment coupling. In particular, we investigate the limit of increasing system size and density of states, i.e. the macroscopic limit. In this limit, a universal behaviour of entanglement emerges following a ''reference trajectory'', similar to the central role of the entanglement dynamics of a maximally entangled state found in the first part of the present work. (orig.)

  12. Benchmarks and statistics of entanglement dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Tiersch, Markus

    2009-09-04

    In the present thesis we investigate how the quantum entanglement of multicomponent systems evolves under realistic conditions. More specifically, we focus on open quantum systems coupled to the (uncontrolled) degrees of freedom of an environment. We identify key quantities that describe the entanglement dynamics, and provide efficient tools for its calculation. For quantum systems of high dimension, entanglement dynamics can be characterized with high precision. In the first part of this work, we derive evolution equations for entanglement. These formulas determine the entanglement after a given time in terms of a product of two distinct quantities: the initial amount of entanglement and a factor that merely contains the parameters that characterize the dynamics. The latter is given by the entanglement evolution of an initially maximally entangled state. A maximally entangled state thus benchmarks the dynamics, and hence allows for the immediate calculation or - under more general conditions - estimation of the change in entanglement. Thereafter, a statistical analysis supports that the derived (in-)equalities describe the entanglement dynamics of the majority of weakly mixed and thus experimentally highly relevant states with high precision. The second part of this work approaches entanglement dynamics from a topological perspective. This allows for a quantitative description with a minimum amount of assumptions about Hilbert space (sub-)structure and environment coupling. In particular, we investigate the limit of increasing system size and density of states, i.e. the macroscopic limit. In this limit, a universal behaviour of entanglement emerges following a ''reference trajectory'', similar to the central role of the entanglement dynamics of a maximally entangled state found in the first part of the present work. (orig.)

  13. Ökonomie der Bandbreite: Evolutionär-ökonomische und kulturanthropologische Überlegungen zu Schnittstellen in Mensch-Maschine-Komplexen

    Directory of Open Access Journals (Sweden)

    Manuel Wäckerle

    2012-09-01

    Full Text Available In diesem Artikel diskutieren wir Bandbreite als kognitive, kulturelle und technische Regel, als eine Regel, die Informationsübertragung pro Zeiteinheit beschränkt. Wir verstehen Wirtschaft, Kultur und Gesellschaft als regelbasiertes evolvierendes System und geben der Bandbreite als generische Regel eine zentrale Rolle. Dabei untersuchen wir theoretisch die wechselwirkenden Prozesse der Ausbeutung und Ausweitung von Bandbreite in Mensch-Maschine-Komplexen. Des Weiteren verweisen wir auf die historische Dimension der digitalisierten Gesellschaft und diskutieren kulturelle Entwicklungen von evolvierten Prothesen. In diesem Zusammenhang formulieren wir eine Genealogie von Gleichheit und Freiheit im Netz. Abschließend betrachten wir zwei Beispiele von evolvierenden Prothesen: Das „Automated Trading“ und die Thematik des „Freundschaftskapitals bei Facebook“. Es zeigt sich, dass sich in beiden Beispielen, so unterschiedlich ihre Implikationen auf ersten Blick auch sind, systemisches Risiko auf ähnliche Art und Weise akkumuliert. Unser Artikel versucht einerseits wesentliche Aspekte der Ökonomie der Bandbreite aufzuzeigen, andererseits erste interdisziplinäre Denkschemata für ebendiese zu entwickeln.

  14. Kants Theorie der Sonne: Physikgeschichte

    Science.gov (United States)

    Jacobi, Manfred

    2005-01-01

    Im Rahmen seiner Kosmogonie entwickelte der junge Immanuel Kant eine Theorie der Sonne. Sie ist ein einzigartiges Zeugnis seiner intuitiven Vorstellungskraft und beweist auch die Leistungsfähigkeit der damaligen, vorwiegend von Newton geprägten Weltsicht. Entstehung, Aufbau und Dynamik der Sonne werden in Kants Theorie ebenso erklärt wie etwa das Phänomen der Sonnenflecken.

  15. Transverse entanglement migration in Hilbert space

    International Nuclear Information System (INIS)

    Chan, K. W.; Torres, J. P.; Eberly, J. H.

    2007-01-01

    We show that, although the amount of mutual entanglement of photons propagating in free space is fixed, the type of correlations between the photons that determine the entanglement can dramatically change during propagation. We show that this amounts to a migration of entanglement in Hilbert space, rather than real space. For the case of spontaneous parametric down-conversion, the migration of entanglement in transverse coordinates takes place from modulus to phase of the biphoton state and back again. We propose an experiment to observe this migration in Hilbert space and to determine the full entanglement

  16. Einfluss einer vierstündigen Hypoxieexposition (12,5% O 2) auf die Expression von hypoxie-und stressinduzierbaren Proteinen in Zusammenhang mit Antioxidantien

    OpenAIRE

    Höchst, Katrin

    2009-01-01

    Eine adäquate Sauerstoffversorgung des menschlichen Organismus ist eine essentielle Grundvoraussetzung für die Funktion aller Organe und Körpersysteme. In dieser Arbeit beschäftigen wir uns mit der Auswirkung von Hypoxie auf das Immunsystem, was auch im Sport in Bezug auf Höhentraining von Bedeutung ist. Wir untersuchten den Effekt moderater Hypoxie auf die Regulation von verschiedenen Stressantworten des Immunsystems (oxidativer Burst, Phagozytose, Expression der Hitzschockproteine HSP ...

  17. Characterization of two-qubit perfect entanglers

    International Nuclear Information System (INIS)

    Rezakhani, A.T.

    2004-01-01

    Here we consider perfect entanglers from another perspective. It is shown that there are some special perfect entanglers which can maximally entangle a full product basis. We explicitly construct a one-parameter family of such entanglers together with the proper product basis that they maximally entangle. This special family of perfect entanglers contains some well-known operators such as controlled-NOT (CNOT) and double-CNOT, but not √(SWAP). In addition, it is shown that all perfect entanglers with entangling power equal to the maximal value (2/9) are also special perfect entanglers. It is proved that the one-parameter family is the only possible set of special perfect entanglers. Also we provide an analytic way to implement any arbitrary two-qubit gate, given a proper special perfect entangler supplemented with single-qubit gates. Such gates are shown to provide a minimum universal gate construction in that just two of them are necessary and sufficient in implementation of a generic two-qubit gate

  18. Continuous variable polarization entanglement, experiment and analysis

    International Nuclear Information System (INIS)

    Bowen, Warwick P; Treps, Nicolas; Schnabel, Roman; Ralph, Timothy C; Lam, Ping Koy

    2003-01-01

    We generate and characterize continuous variable polarization entanglement between two optical beams. We first produce quadrature entanglement, and by performing local operations we transform it into a polarization basis. We extend two entanglement criteria, the inseparability criteria proposed by Duan et al (2000 Phys. Rev. Lett. 84 2722) and the Einstein-Podolsky-Rosen (EPR) paradox criteria proposed by Reid and Drummond (1988 Phys. Rev. Lett. 60 2731), to Stokes operators; and use them to characterize the entanglement. Our results for the EPR paradox criteria are visualized in terms of uncertainty balls on the Poincare sphere. We demonstrate theoretically that using two quadrature entangled pairs it is possible to entangle three orthogonal Stokes operators between a pair of beams, although with a bound √3 times more stringent than for the quadrature entanglement

  19. Continuous variable polarization entanglement, experiment and analysis

    Energy Technology Data Exchange (ETDEWEB)

    Bowen, Warwick P [Department of Physics, Faculty of Science, Australian National University, ACT 0200 (Australia); Treps, Nicolas [Department of Physics, Faculty of Science, Australian National University, ACT 0200 (Australia); Schnabel, Roman [Department of Physics, Faculty of Science, Australian National University, ACT 0200 (Australia); Ralph, Timothy C [Department of Physics, Centre for Quantum Computer Technology, University of Queensland, St Lucia, QLD 4072 (Australia); Lam, Ping Koy [Department of Physics, Faculty of Science, Australian National University, ACT 0200 (Australia)

    2003-08-01

    We generate and characterize continuous variable polarization entanglement between two optical beams. We first produce quadrature entanglement, and by performing local operations we transform it into a polarization basis. We extend two entanglement criteria, the inseparability criteria proposed by Duan et al (2000 Phys. Rev. Lett. 84 2722) and the Einstein-Podolsky-Rosen (EPR) paradox criteria proposed by Reid and Drummond (1988 Phys. Rev. Lett. 60 2731), to Stokes operators; and use them to characterize the entanglement. Our results for the EPR paradox criteria are visualized in terms of uncertainty balls on the Poincare sphere. We demonstrate theoretically that using two quadrature entangled pairs it is possible to entangle three orthogonal Stokes operators between a pair of beams, although with a bound {radical}3 times more stringent than for the quadrature entanglement.

  20. Entanglement and decoherence in high energy physics

    International Nuclear Information System (INIS)

    Bertlmann, R.

    2005-01-01

    Full text: The phenomenon of entanglement occurs in very heavy quantum systems of particle physics. We find analogies but also differences to the entangled spin-1/2 or photon systems. In particular we discuss the features of entangled 'strangeness', the K-meson system, where a Bell inequality exists which has a remarkable connection to CP (charge conjugation and parity) and its violation. Stability of entangled quantum states is studied by allowing the system to interact with an environment. We consider possible decoherence of entangled 'beauty', the B-meson system, produced at the particle colliders at very high energies (10 GeV). Finally, we discuss a criterion for detecting entangled/separable states, a generalized Bell inequality and entanglement witness. We illustrate its geometric features by the two-spin example Alice and Bob. (author)

  1. Entanglement in Gaussian matrix-product states

    International Nuclear Information System (INIS)

    Adesso, Gerardo; Ericsson, Marie

    2006-01-01

    Gaussian matrix-product states are obtained as the outputs of projection operations from an ancillary space of M infinitely entangled bonds connecting neighboring sites, applied at each of N sites of a harmonic chain. Replacing the projections by associated Gaussian states, the building blocks, we show that the entanglement range in translationally invariant Gaussian matrix-product states depends on how entangled the building blocks are. In particular, infinite entanglement in the building blocks produces fully symmetric Gaussian states with maximum entanglement range. From their peculiar properties of entanglement sharing, a basic difference with spin chains is revealed: Gaussian matrix-product states can possess unlimited, long-range entanglement even with minimum number of ancillary bonds (M=1). Finally we discuss how these states can be experimentally engineered from N copies of a three-mode building block and N two-mode finitely squeezed states

  2. Classical-driving-assisted entanglement dynamics control

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ying-Jie, E-mail: yingjiezhang@qfnu.edu.cn [Shandong Provincial Key Laboratory of Laser Polarization and Information Technology, Department of Physics, Qufu Normal University, Qufu 273165 (China); Han, Wei [Shandong Provincial Key Laboratory of Laser Polarization and Information Technology, Department of Physics, Qufu Normal University, Qufu 273165 (China); Xia, Yun-Jie, E-mail: yjxia@qfnu.edu.cn [Shandong Provincial Key Laboratory of Laser Polarization and Information Technology, Department of Physics, Qufu Normal University, Qufu 273165 (China); Fan, Heng, E-mail: hfan@iphy.ac.cn [Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190 (China); Collaborative Innovation Center of Quantum Matter, Beijing, 100190 (China)

    2017-04-15

    We propose a scheme of controlling entanglement dynamics of a quantum system by applying the external classical driving field for two atoms separately located in a single-mode photon cavity. It is shown that, with a judicious choice of the classical-driving strength and the atom–photon detuning, the effective atom–photon interaction Hamiltonian can be switched from Jaynes–Cummings model to anti-Jaynes–Cummings model. By tuning the controllable atom–photon interaction induced by the classical field, we illustrate that the evolution trajectory of the Bell-like entanglement states can be manipulated from entanglement-sudden-death to no-entanglement-sudden-death, from no-entanglement-invariant to entanglement-invariant. Furthermore, the robustness of the initial Bell-like entanglement can be improved by the classical driving field in the leaky cavities. This classical-driving-assisted architecture can be easily extensible to multi-atom quantum system for scalability.

  3. Optimal Entanglement Witnesses for Qubits and Qutrits

    International Nuclear Information System (INIS)

    Bertlmann, R.A.; Durstberger, K.; Hiesmayr, B.C.; Krammer, P.

    2005-01-01

    Full text: We give a review of the connection between an optimal entanglement witness and the Hilbert-Schmidt measure of entanglement (that is the minimal distance of an entangled state to the set of separable states): a generalized Bell inequality is derived within the concept of entanglement witnesses, in the sense that a violation of the inequality detects entanglement and not non-locality liKEX usual Bell inequalities do. It can be seen that the maximal violation equals the Hilbert-Schmidt measure. Furthermore, since finding the nearest separable state to a given entangled state is rather difficult, a method for checking an estimated nearest separable state is presented. This is illustrated with isotropic qubit and qutrit states; the Hilbert-Schmidt measure, the optimal entanglement witness and the maximal violation of the GBI are calculated for those cases. Possible generalizations for arbitrary dimensions are discussed. (author)

  4. Genetische Aspekte der Osteoporose

    Directory of Open Access Journals (Sweden)

    Obermayer-Pietsch B

    1998-01-01

    Full Text Available Eine genetische Grundlage der Osteoporose wird neben Umwelteinflüssen seit langem vermutet. Bei Familien- und Zwillingsuntersuchungen wurden erbliche Einflüsse von etwa 46-75 % auf die Knochendichte - abhängig von den Meßorten - festgestellt. Neben einer genetischen Belastung durch eine betroffene Mutter wurde auch ein väterlicher Einfluß auf die Ausprägung der individuellen Knochendichte nachgewiesen. Verschiedenste Kandidatengene wurden bisher untersucht. Bedeutende Beiträge dazu sind in den genetischen Polymorphismen von Östrogen- und anderen Hormonrezeptoren und anderen wichtigen Genorten zu sehen. Eine Durchleuchtung des genetischen Hintergrundes der Osteoporose kann in Zukunft verbesserte Möglichkeiten der Früherkennung und Differenzierung der Diagnostik eröffnen und damit zu neuen Strategien für Prophylaxe und Therapie der Osteoporose führen.

  5. Comparison of rigid and swivelling rotor hubs for a MW wind power system, using the example of the WKA Autoflug A 1200; Vergleich von starrer und Pendel-Rotornabe fuer eine Windkraftanlage der Megawatt-Leistungsklasse am Beispiel der WKA Autoflug A 1200

    Energy Technology Data Exchange (ETDEWEB)

    Quell, P. [aerodyn Energiesysteme GmbH, Rendsburg (Germany)

    1996-12-31

    Developments in the MW range are a further illustration of the well-known problem that a linear increase of the rotor surface area will result in an overproportional increase of mass. One classical approach for reducing weight is the installation of a two-blade rotor with a swivelling hub. In the course of the development activities for the 1.2 MW A1200 wind power system of Autoflug Energietechnik GmbH, it was investigated whether a pendulum hub is a technically and economically feasible concept for a plant of this size. For this purpose, two otherwise identical plants were projected and compared, one with a rigid hub and the other with a swivelling hub. Both systems were simulated using the dynamic program GAROS. With the loads thus determined, both concepts are detailed enough to permit a comprehensive cost comparison in consideration of the masses, the resulting cost, performance and reliability. [Deutsch] Der Entwicklungsprozess der Megawatt-Anlagen verdeutlicht den aus frueheren Untersuchungen bekannten Zusammenhang eines ueberproportionalen Massenzuwachses bei linear steigender Rotorflaeche. Ein klassischer Ansatz zur Reduzierung des Anlagengewichtes ist der Einsatz eines Zweiblatt-Rotors in Verbindung mit einer Pendelnabe. Im Rahmen der Entwicklungstaetigkeit fuer die 1,2 MW-Windkraftanlage A 1200 der Fa. Autoflug Energietechnik GmbH wurde untersucht, inwieweit der Einsatz einer Pendelnabe fuer eine Anlage dieser Groessenordnung ein technisch und wirtschaftlich sinnvolles Konzept darstellen kann. Dazu wurden zwei grundsaetzlich gleiche Anlagen mit Zweiblatt-Rotor unter Verwendung einer Pendelnabe und einer starren Nabe konzipiert und gegenuebergestellt. Zur Bewertung des Anlagenverhaltens sowie zur Ermittlung realitaetsnaher Belastungen werden sowohl die Anlagenversion mit Pendelnabe als auch die Version mit starrer Nabe mit dem Dynamikprogramm GAROS simuliert. Basierend auf den ermittelten Lasten werden beide Konzepte so detailliert, dass ein umfassender

  6. Bessel-Gaussian entanglement; presentation

    CSIR Research Space (South Africa)

    Mclaren, M

    2013-07-01

    Full Text Available mode Hologram Page 9 Violation of Bell’s inequality demonstrates entanglement © CSIR 2013 www.csir.co.za P ro b ab il it y Classical Quantum mechanical M. McLaren et al.,2012, Opt. Express, 20, 23589 Page 10 Comparison...

  7. Basic logic and quantum entanglement

    International Nuclear Information System (INIS)

    Zizzi, P A

    2007-01-01

    As it is well known, quantum entanglement is one of the most important features of quantum computing, as it leads to massive quantum parallelism, hence to exponential computational speed-up. In a sense, quantum entanglement is considered as an implicit property of quantum computation itself. But... can it be made explicit? In other words, is it possible to find the connective 'entanglement' in a logical sequent calculus for the machine language? And also, is it possible to 'teach' the quantum computer to 'mimic' the EPR 'paradox'? The answer is in the affirmative, if the logical sequent calculus is that of the weakest possible logic, namely Basic logic. - A weak logic has few structural rules. But in logic, a weak structure leaves more room for connectives (for example the connective 'entanglement'). Furthermore, the absence in Basic logic of the two structural rules of contraction and weakening corresponds to the validity of the no-cloning and no-erase theorems, respectively, in quantum computing

  8. Basic logic and quantum entanglement

    Energy Technology Data Exchange (ETDEWEB)

    Zizzi, P A [Dipartimento di Matematica Pura ed Applicata, Via Trieste 63, 35121 Padova (Italy)

    2007-05-15

    As it is well known, quantum entanglement is one of the most important features of quantum computing, as it leads to massive quantum parallelism, hence to exponential computational speed-up. In a sense, quantum entanglement is considered as an implicit property of quantum computation itself. But... can it be made explicit? In other words, is it possible to find the connective 'entanglement' in a logical sequent calculus for the machine language? And also, is it possible to 'teach' the quantum computer to 'mimic' the EPR 'paradox'? The answer is in the affirmative, if the logical sequent calculus is that of the weakest possible logic, namely Basic logic. - A weak logic has few structural rules. But in logic, a weak structure leaves more room for connectives (for example the connective 'entanglement'). Furthermore, the absence in Basic logic of the two structural rules of contraction and weakening corresponds to the validity of the no-cloning and no-erase theorems, respectively, in quantum computing.

  9. Transitivity of an entangled choice

    International Nuclear Information System (INIS)

    Makowski, Marcin; Piotrowski, Edward W

    2011-01-01

    We describe a quantum model of a simple choice game (constructed upon the entangled state of two qubits), which involves the fundamental problem of transitive-intransitive preferences. We compare attainability of optimal intransitive strategies in both classical and quantum models with the use of geometrical interpretation.

  10. Entangling light in high dimensions

    NARCIS (Netherlands)

    Pors, Jan Bardeus

    2011-01-01

    Quantum entanglement is a fundamental trait of quantum mechanics that causes the information about the properties of two (or more) objects to be inextricably linked. When a measurement on one of the objects is performed, the state of the other object is immediately altered, even when these objects

  11. Computational complexity in entanglement transformations

    Science.gov (United States)

    Chitambar, Eric A.

    In physics, systems having three parts are typically much more difficult to analyze than those having just two. Even in classical mechanics, predicting the motion of three interacting celestial bodies remains an insurmountable challenge while the analogous two-body problem has an elementary solution. It is as if just by adding a third party, a fundamental change occurs in the structure of the problem that renders it unsolvable. In this thesis, we demonstrate how such an effect is likewise present in the theory of quantum entanglement. In fact, the complexity differences between two-party and three-party entanglement become quite conspicuous when comparing the difficulty in deciding what state changes are possible for these systems when no additional entanglement is consumed in the transformation process. We examine this entanglement transformation question and its variants in the language of computational complexity theory, a powerful subject that formalizes the concept of problem difficulty. Since deciding feasibility of a specified bipartite transformation is relatively easy, this task belongs to the complexity class P. On the other hand, for tripartite systems, we find the problem to be NP-Hard, meaning that its solution is at least as hard as the solution to some of the most difficult problems humans have encountered. One can then rigorously defend the assertion that a fundamental complexity difference exists between bipartite and tripartite entanglement since unlike the former, the full range of forms realizable by the latter is incalculable (assuming P≠NP). However, similar to the three-body celestial problem, when one examines a special subclass of the problem---invertible transformations on systems having at least one qubit subsystem---we prove that the problem can be solved efficiently. As a hybrid of the two questions, we find that the question of tripartite to bipartite transformations can be solved by an efficient randomized algorithm. Our results are

  12. Lessing und der Islam

    OpenAIRE

    Muslim, Zahim Mohammed

    2010-01-01

    „Lessing und der Islam“ beschäftigt sich unparteiisch mit Lessings Auseinandersetzung mit dem Islam. Die Arbeit setzt sich das Ziel, den Leser und den Literaturkennern sowie der deutschen Bibliothek der Germanistik etwas von Lessings Auseinandersetzung mit dem Islam in die Hand zu geben, die bis heute als großes Modell für die interkulturelle und interreligiöse Menschheitstoleranzdebatte im Gedächtnis der deutschen Literatur vorhanden ist. Im ersten Teil widmet sich die vorliegende Arbeit de...

  13. Results of the evaluation of environmental medical documentation and progress sheets in Schleswig-Holstein from 1995 to 1999. A report on behalf of the Environmental Committee of the Schleswig-Holstein Association of Health Service Physicians; Ergebnisse der Auswertung umweltmedizinischer Dokumentations- und Verlaufsboegen in Schleswig-Holstein von 1995 - 1999. Ein Bericht im Auftrage des Umweltausschusses der Kassenaerztlichen Vereinigung Schleswig-Holstein

    Energy Technology Data Exchange (ETDEWEB)

    Wassermann, O.; Bauer, A.; Alsen-Hinrichs, C.

    2001-07-01

    documented it was possible to completely stop the exposure. 65% of these patients are reported to have experienced an alleviation of all their symptoms and 30% to have experienced alleviation of some of their symptoms. [German] Es wurde eine Dokumentation umweltmedizinischer Faelle aus den Jahren 1995-1999 in Schleswig-Holstein vorgenommen. Die Dokumentation umfasst standardisierte umweltmedizinische Fall- und Verlaufsdokumentationen. Es wurden 916 Dokumentationsboegen in die Auswertung aufgenommen. Zusaetzlich wurden 508 umweltmedizinische Verlaufsboegen in die Auswertung einbezogen. Bei 36% der Faelle wurde der Zusammenhang zwischen Schadstoffbelastung und Symptomatik aufgrund vorliegender Schadstoffmesswerte und/oder Verlaufsinformationen als 'wahrscheinlich' charakterisiert. Bei 27% der Patienten wurde aufgrund der Anamnese der deutliche Verdacht auf eine umweltmedizinische Genese der gesundheitlichen Beschwerden erhoben. Bei 13% der dokumentierten Faelle war dieser Zusammenhang unsicher. Bei 15% der dokumentierten Faelle lag eine Allergie und/oder Ueberempfindlichkeit gegenueber umweltmedizinisch relevanten Expositionsfaktoren vor. Bei 10% der Faelle wurde im Verlauf der aerztlichen Untersuchungen eine andere Erkrankung als Ursache der Beschwerden diagnostiziert bzw. ergab die umweltmedizinische Abklaerung keine Anhaltspunkte fuer relevante Schadstoffexpositionen. Es wurden Alter, Geschlecht, Symptomatik, vermutete und nachgewiesene Expositionsfaktoren sowie Verlaeufe nach Sanierungsmassnahmen/Expositionsstopp dokumentiert und insgesamt sowie in Abhaengigkeit von der Art der Exposition ausgewertet. Biozide (32%), Schimmelpilze (27%), Amalgam (22%), Loesemittel (21%) und Formaldehyd (16%) wurden am haeufigsten als umweltmedizinisch relevante Expositionsfaktoren dokumentiert. Bei 52% der 508 Patienten, deren Krankheitsverlauf dokumentiert wurde, wurde die umweltmedizinische Diagnose durch den Verlauf insgesamt und bei 23% zum Teil bestaetigt. Bei 273 (54%) der

  14. Displacement-enhanced entanglement distillation of single-mode-squeezed entangled states

    DEFF Research Database (Denmark)

    Tipsmark, Anders; Neergaard-Nielsen, Jonas Schou; Andersen, Ulrik Lund

    2013-01-01

    It has been shown that entanglement distillation of Gaussian entangled states by means of local photon subtraction can be improved by local Gaussian transformations. Here we show that a similar effect can be expected for the distillation of an asymmetric Gaussian entangled state that is produced...... by a single squeezed beam. We show that for low initial entanglement, our largely simplified protocol generates more entanglement than previous proposed protocols. Furthermore, we show that the distillation scheme also works efficiently on decohered entangled states as well as with a practical photon...

  15. Das Portfolio als Beitrag zur Reflexion persönlicher Kompetenzentwicklung in der Religions-/PädagogInnenbildung. Chancen einer neuen Lern- und Bewertungskultur - am Beispiel einer Fallstudie

    Directory of Open Access Journals (Sweden)

    Alexander van Dellen

    2013-10-01

    Full Text Available ”Competence orientation” in pedagogy education constitutes a central point within the draft laws formulated on the 12th of June 2013. These see the use of portfolios as playing a crucial part of religious instruction education. This is based on the expectation that portfolios act as continuous and helpful companions throughout the various educational phases and therefore benefit students’ reflections on individual competence development. Portfolios allow effective measures towards personal development as a professional educator to be taken. The format at hand, which was conceived as a case study at the Institute for Practical Theology (department catechetics, religious education studies and religious didactics at the Faculty of Catholic Theology at the University of Innsbruck, is intended to be used as a basis for a discussion on the benefits of a continuous portfolio as a reflection tool for students’ personal competence development. The first step illustrates the genesis and structure of the portfolio concept (2, so that the second step can then outline the potentials held by this new culture of using portfolios as learning and assessment tools in religious instruction education (3. In den vom österreichischen Parlament am 12. Juni 2013 beschlossenen Gesetzesentwürfen zur zukünftigen PädagogInnenbildung stellt die Kompetenzorientierung einen Kernpunkt dar. In diesem Zusammenhang wird in der Ausbildung von Religions-/PädagogInnen der Einsatz von Portfolios verstärkt eine zentrale Rolle spielen. Damit ist die Hoffnung verbunden, dass das Portfolio als Kontinuum in den unterschiedlichen Phasen der Religions-/PädagogInnenbildung für Studierende ein hilfreiches Instrument für die Reflexion ihrer individuellen Kompetenzentwicklung bildet. Somit kann eine wirksame Maßnahme der persönlichen Entwicklung in der Professionalisierung für den Lehrberuf gesetzt werden. In den vorliegenden Ausführungen soll auf der Grundlage einer

  16. Development of active barriers for removing heavy metals from mine water: Freiberg colliery, Sachsen; Entwicklung aktiver Barrieren fuer die Entfernung von Schwermetallen aus Grubenwaessern am Beispiel der Freiberger Grube, Sachsen

    Energy Technology Data Exchange (ETDEWEB)

    Zoumis, T.

    2003-07-01

    Mine water treatment is costly, difficult, and requires extensive surface installations. The author explains the development of geochemical ('active') barriers of low-cost materials. The materials investigated were industrial residues (red sludge, fly ash, tinder residues, porous concrete residues), natural materials (bark, zeolite, bentonite, hydroxyl apatite), and commercial products (GEH, Ratio Pur MF-S). Investigations focused on density, specific surface, grain size, and acid neutralization capacity. In the final stage, experiments were made on heavy metal removal from a model water. [German] Einen grossen Anteil an der Schwermetallbelastung in Fluessen haben toxische Abwaesser aus Bergbaugebieten (Grubenwaesser). Die Moeglichkeit der Behandlung sind sehr aufwendig, kostenintensiv und nur 'ueber Tage' durchfuehrbar. Die vorliegende Arbeit erlaeutert die Behandlung von Grubenwaessern mit geochemischen ('aktiven') Barrieren. Es werden aktive Barrieren entwickelt, die in einen Schacht eingebracht werden koennen, um eine Schwermetallausbreitung zu unterbinden. In diesem Zusammenhang werden kostenguenstige Materialien untersucht, die Schadstoffe durch chemische und/oder physikalische Mechanismen aus Wasser entfernen koennen. Untersucht wurden industrielle Reststoffe (Rotschlamm, Flugasche, Zunderrueckstaende, Porenbetonabfall), natuerliche Materialien (Baumrinde, Zeolith, Bentonit, Hydroxylapatit) und kommerzielle Produkte (GEH, Ratio Pur MF-S). Die Materialien werden hinsichtlich der Dichte, der spezifischen Oberflaeche, der Korngroesse und der Saeureneutralisationskapazitaet charakterisiert. Anschliessend wurden Versuche zur Schwermetallentfernung aus einem Modellwasser durchgefuehrt. (orig.)

  17. Physiological and technical limitations of functional magnetic resonance imaging (fMRI) - consequences for clinical use; Physiologische und technische Grenzen der funktionellen Magnetresonanztomographie und die damit verbundenen Konsequenzen fuer die klinische Anwendung

    Energy Technology Data Exchange (ETDEWEB)

    Wuestenberg, T. [Neurologische Klinik der Charite, Humboldt-Universitaet Berlin (Germany); Neurologische Klinik der Charite, Humboldt-Universitaet Berlin, Schumannstrasse 20/21, 10117, Berlin (Germany); Jordan, K. [Institut fuer Psychologie II, Otto-von-Guericke-Universitaet Magdeburg (Germany); Giesel, F.L. [Abteilung fuer onkologische Diagnostik und Therapie, Deutsches Krebsforschungszentrum Heidelberg (Germany); Villringer, A. [Neurologische Klinik der Charite, Humboldt-Universitaet Berlin (Germany)

    2003-07-01

    Functional magnetic resonance imaging (fMRI) is the most common noninvasive technique in functional neuroanatomy. The capabilities and limitations of the method will be discussed based on a short review of the current knowledge about the neurovascular relationship. The focus of this article is on current methodical and technical problems regarding fMRI-based detection and localization of neuronal activity. Main error sources and their influence on the reliability and validity of fMRI-methods are presented. Appropriate solution strategies will be proposed and evaluated. Finally, the clinical relevance of MR-based diagnostic methods are discussed. (orig.) [German] Die funktionelle Magnetresonanztomographie (fMRT) ist eines der wichtigsten Verfahren der funktionellen Neuroanatomie. Aufbauend auf einer kurzen Darstellung des aktuellen Wissensstands bzgl. des Zusammenhangs zwischen lokaler neuronaler Aktivitaet und haemodynamischer Reaktion werden ausgewaehlte Moeglichkeiten und Grenzen des Verfahrens fuer die klinische Anwendung diskutiert. Der Schwerpunkt liegt dabei auf der Darstellung der derzeitigen methodischen und technischen Einschraenkungen hinsichtlich einer fMRT-basierten Detektion und Lokalisierung neuronaler Aktivitaet. Es werden die Hauptfehlerquellen und ihre Auswirkungen auf die Reliabilitaet und Validitaet des Verfahrens erlaeutert und aktuelle Loesungsansaetze diskutiert. Abschliessend erfolgt eine Bewertung der aktuellen klinischen Relevanz funktioneller MR-Diagnosemethoden. (orig.)

  18. Auswirkungen der pharmakologischen Osteoporosetherapie in der Zahnheilkunde

    Directory of Open Access Journals (Sweden)

    Gruber R

    2013-01-01

    Full Text Available Die pharmakologische Osteoporosetherapie greift systemisch in den Knochenumbau ein und erreicht damit auch den Kieferknochen. Die komplexen Auswirkungen auf die Klinik der Parodontologie und Implantologie werden im vorliegenden Beitrag beispielhaft dargestellt. Vitamin D3 fördert die Heilung nach Parodontalchirurgie. Bisphosphonate können die parodontale Situation während der Nachsorgetherapie verbessern und möglicherweise die Einheilung von dentalen Implantaten fördern. Die meisten klinischen Studien zeigen keine negativen Effekte in Bezug auf die Entstehung von Osteonekrosen des Kieferknochens. Die Bedeutung von Strontium für die Zahnheilkunde ist primär in der Kariesprävention angesiedelt. Erste klinische Pilotstudien unterstützen eine mögliche Wirkung von Teriparatid auf die Einheilung dentaler Implantate. Bedeutsam erscheinen die positiven Effekte von Teriparatid bei der Regeneration nach chirurgischer Parodontaltherapie. Die vorliegenden Studien zeigen, dass die pharmakologische Osteoporosetherapie einen positiven Einfluss auf die Klinik der Parodontologie und Implantologie haben kann.

  19. Local copying of orthogonal entangled quantum states

    International Nuclear Information System (INIS)

    Anselmi, Fabio; Chefles, Anthony; Plenio, Martin B

    2004-01-01

    In classical information theory one can, in principle, produce a perfect copy of any input state. In quantum information theory, the no cloning theorem prohibits exact copying of non-orthogonal states. Moreover, if we wish to copy multiparticle entangled states and can perform only local operations and classical communication (LOCC), then further restrictions apply. We investigate the problem of copying orthogonal, entangled quantum states with an entangled blank state under the restriction to LOCC. Throughout, the subsystems have finite dimension D. We show that if all of the states to be copied are non-maximally entangled, then novel LOCC copying procedures based on entanglement catalysis are possible. We then study in detail the LOCC copying problem where both the blank state and at least one of the states to be copied are maximally entangled. For this to be possible, we find that all the states to be copied must be maximally entangled. We obtain a necessary and sufficient condition for LOCC copying under these conditions. For two orthogonal, maximally entangled states, we provide the general solution to this condition. We use it to show that for D = 2, 3, any pair of orthogonal, maximally entangled states can be locally copied using a maximally entangled blank state. However, we also show that for any D which is not prime, one can construct pairs of such states for which this is impossible

  20. Holographic entanglement entropy and the extended phase structure of STU black holes

    International Nuclear Information System (INIS)

    Caceres, Elena; Nguyen, Phuc H.; Pedraza, Juan F.

    2015-01-01

    We study the extended thermodynamics, obtained by considering the cosmological constant as a thermodynamic variable, of STU black holes in 4-dimensions in the fixed charge ensemble. The associated phase structure is conjectured to be dual to an RG-flow on the space of field theories. We find that for some charge configurations the phase structure resembles that of a Van der Waals gas: the system exhibits a family of first order phase transitions ending in a second order phase transition at a critical temperature. We calculate the holographic entanglement entropy for several charge configurations and show that for the cases where the gravity background exhibits Van der Waals behavior, the entanglement entropy presents a transition at the same critical temperature. To further characterize the phase transition we calculate appropriate critical exponents and show that they coincide. Thus, the entanglement entropy successfully captures the information of the extended phase structure. Finally, we discuss the physical interpretation of the extended space in terms of the boundary QFT and construct various holographic heat engines dual to STU black holes.

  1. Therapeutic management of radiation-induced oral mucositis; Therapeutische Beeinflussung der radiogenen oralen Mukositis

    Energy Technology Data Exchange (ETDEWEB)

    Doerr, W. [Klinik und Poliklinik fuer Strahlentherapie, Universitaetsklinikum Carl Gustav Carus, Technische Univ. Dresden (Germany); Doelling-Jochem, I. [Klinik und Poliklinik fuer Strahlentherapie, Universitaetsklinikum Carl Gustav Carus, Technische Univ. Dresden (Germany); Baumann, M. [Klinik und Poliklinik fuer Strahlentherapie, Universitaetsklinikum Carl Gustav Carus, Technische Univ. Dresden (Germany); Herrmann, T. [Klinik und Poliklinik fuer Strahlentherapie, Universitaetsklinikum Carl Gustav Carus, Technische Univ. Dresden (Germany)

    1997-04-01

    Proliferation von Tumorstammzellen, die in der Folge die Tumorheilungsaussichten drastisch verringern kann. Zudem fuehren ueberschiessende Akutreaktionen in vielen Faellen zu einer Verstaerkung von spaeten Strahlenfolgen. Die Verminderung der Schleimhautreaktion mit dem Ziel der Vermeidung von Bestrahlungspausen und der Verminderung von Spaetschaeden kann den therapeutischen Erfolg der Radiotherapie entscheidend verbessern. Verschiedene Ansaetze zur Beeinflussung der strahleninduzierten Mukositis auf symptomatischer oder strahlen- und epithelbiologischer Grundlage wurden zusammengefass und systematisch dargestellt. Es existiert eine Vielzahl prophylaktischer und therapeutischer Ansaetze zur Verminderung akuter radiogener Reaktionen der Mundschleimhaut. Haeufig ist die Wirksamkeit jedoch nur fuer Chemotherapie oder im Zusammenhang mit einer immunsuppressiven Therapie nachgewiesen, so dass oft eher ein systemischer als ein lokaler Effekt angenommen werden muss. Als allgemeine Mukositisprophylaxe koennen neben einer Zahnsanierung regelmaessige mundhygienische Massnahmen sowie antiseptische Spuelungen herangezogen werden. Die Bedeutung einer engmaschigen persoenlichen Betreuung der Patienten ist zu betonen. Das Anlegen eines perkutanen endoskopischen Gastrostoma muss am Zustand des Patienten sowie an der Ausdehnung und Lage des Bestrahlungsfeldes und damit der zu erwartenden Beeintraechtigung der Nahrungsaufnahme orientiert werden. Als therapeutische Massnahmen bei manifesten Schleimhautreaktionen kommen eine lokale bzw. systemische Schmerzbehandlung sowie die lokale Applikation von Antimykotika und Antibiotika in Betracht. (orig./VHE)

  2. Lokale Bildgebung der Prostata

    NARCIS (Netherlands)

    Walz, J.; Loch, T.; Salomon, G.; Wijkstra, H.

    2013-01-01

    In den letzten Jahren wurden neue Verfahren für die Bildgebung der Prostata entwickelt, um die Diagnostik des Prostatakarzinoms zu verbessern. Hierbei wurde v. a. der transrektale Ultraschall (TRUS) zum sog. „enhanced ultrasound" weiterentwickelt. Die Elastographie zeigt in mehreren Studien gute

  3. van der Waals

    Indian Academy of Sciences (India)

    in the world without learning the 'van der Waals equation'. ... theory”. Those days, however, molecules were assumed to be point masses occupying no .... was 36 to obtain his PhD due to the prevailing social conditions. van der Waals died in ...

  4. Implantate in der Augenheilkunde

    Science.gov (United States)

    Dresp, Joachim H.

    Im Bereich der Augenheilkunde findet sich die weltweit am häufigsten ausgeführte chirurgische Massnahme, die operative Behandlung des Grauen Stars: die Katarakt. Bei der Katarakt handelt es sich um eine Eintrübung der natürlichen Augenlinse, die sich je nach Stadium der Erkrankung leicht opak, über milchig bis zu bräunlich präsentiert. Mit dieser Zunahme der Undurchlässigkeit für das sichtbare Licht geht eine Abnahme des Sehvermögens einher, die bis zur totalen Erblindung führen kann. Bedingt durch die sehr eingeschränkten chirurgischen Möglichkeiten in den Ländern der Dritten Welt ist die Katarakt die Erblindungsursache Nummer 1 in der Welt. Ganz im Gegensatz hierzu ist in den industrialisierten Ländern Europas, Amerikas und Asiens die Katarakt-OP die sicherste chirurgische Intervention. In der Augenheilkunde werden Implantate aller drei Aggregatszustände verwendet.

  5. Der soziale Tod

    Directory of Open Access Journals (Sweden)

    Kuljić Todor

    2012-01-01

    Full Text Available Der folgende Text gehört zur kritischen Thanatologie. In allen bekannten Kulturen wurden Normen für den guten und den schlechten Tod von der herrschenden normativen Thanatologien aufgestellt und Kontrollmechanismen installiert. Prämortales und postmortales soziales Sterben ist eine Art der Exklusion der Anderen und wird unter­schiedlich bestimmt: als damnatio memoriae, atlantische Sklaventum, Randständigkeit, Isolation oder als Rollenverlust. Das soziale Tod hat einen Klassenaspekt, als den ganzen Klassen Gedächtnis entnommen wurde. Hier werden nur einige Arten und Beispilen des sozialen Mord kritisch erörtert: damnatio memoriae, politische Mord und Sklaventum. Es handelt sich um die institutionelle Verarbeitung und Kodierung von Sterben und Tod durch Staat, Religion und Politik. In der Geschichte sind verschieden Völkern und Klasssen einem intensiveren sozialen Sterbeprozess und der sozialen Tötung unterworfen. Mit Identitätszerstörung der Beherrschten ist das soziale mit dem physischen Sterben harmonischer zu verbinden. Es ist auch auf die Differenz zwischen sozialen und politischen Tötung hingewiesen. Am Ende sind einige Aspekte der heutigen geheimen Tötung erwähnt. [Projekat Ministarstva nauke Republike Srbije, br. 149005: Društveni akteri i društvene promene u Srbiji 1990-2010

  6. Guidelines on {sup 99m}Tc-DMSA scintigraphy in children; Empfehlungen zur Durchfuehrung der DMSA-Szintigraphie bei Kindern

    Energy Technology Data Exchange (ETDEWEB)

    Piepsz, A. [CHU St. Pierre, Bruessel (Belgium); Colarinha, P. [Instituto Portugues de Oncologia, Lissabon (Portugal); Gordon, I. [Great Ormend Street Hospital for Children, London (United Kingdom); Hahn, K. [Muenchen Univ. (Germany). Klinik fuer Nuklearmedizin; Olivier, P. [CHU Vandoeuvre, Nancy (France); Roca, I.; Velzen, J. van [Hospital Vall d' Hebron, Barcelona (Spain); Sixt, R. [The Queen Silvia Children' s Hospital, Goeteborg (Sweden)

    2000-11-01

    The guidelines are intended to help nuclear medical teams in their daily routine. The guidelines give information relating to indications, imaging parameters, data evaluation and interpretation. The guidelines are in line with the opinions of the Paediatric Committee of EANM and hence focus on approaches adopted in Europe, e.g. as regards selection of the radiopharmaceuticals or activity levels applied. The guidelines should be seen in the context of local quality standards and regulatory requirements. (orig./CB) [German] Zweck dieser Empfehlung ist es, dem Nuklearmedizinischen Team bei Tc-DMSA-Szintigraphie von Kindern Hilfestellung fuer die taegliche Routinepraxis zu geben. Die Empfehlung enthaelt Informationen ueber Indikationen, Aufnahmeparameter, Auswertung und Interpretation der DMSA-Szintigraphie bei Kindern. Die vorliegende Empfehlung fasst die Meinung des Paediatric Committee der EANM zusammen und ist daher mehr auf die Europaeische Vorgehensweise, z.B. bei der Wahl des Radiopharmazeutikums und den verwendeten Aktivitaetsmengen, ausgerichtet. Sie sollte immer in Zusammenhang mit lokalen Qualitaetsstandards und Vorschriften gesehen werden. (orig.)

  7. EINE UNTERSUCHUNG UBER DIE NUTZUNG DER WINDENERGIE IN DER WELT UND IN DER TURKEI

    Directory of Open Access Journals (Sweden)

    Aydoğan ÖZDAMAR

    2000-02-01

    Full Text Available In dieser Arbeit wurde die Nutzung der in Zukunft bei der Energieversorgung eine wichtige Rolle zuspielende Windenergie allgemein bewertet. Zu dem Zweck wurde zuerst Potential und geschichtliche Entwicklung der Windenergienutzung in der Welt und in der Türkei, Entstehung des Windes und Windmessungen betrachtet. Anschließend wurden Kritiken über die Unstetigkeit der Windenergie, der Deckung des Energiebedarfs eines Hauses vollständig von Windenergie und der Wirtschaftlichkeit des Windstroms behandelt und Antworten mit konkreten Beispielen auf diese Kritiken gegeben.

  8. Das Ende eines Mythos: Die männliche Zirkumzision ist nicht mit einer höheren Prävalenz der erektilen Dysfunktion assoziiert – Ergebnisse der „Cottbuser 10.000-Männer-Fragebogenstudie“

    Directory of Open Access Journals (Sweden)

    Brookman-May S

    2014-01-01

    Full Text Available Hintergrund: Es existieren widersprüchliche Daten hinsichtlich des Stellenwertes des männlichen Präputiums bzw. der Zirkumzision im Hinblick auf Erektionsfähigkeit und sexuelle Zufriedenheit des Mannes. Patienten und Methoden: 10.000 entsprechend der stadtbezogenen Altersstruktur ausgewählte Männer in Cottbus (Bundesland Brandenburg erhielten einen 35 Items umfassenden Fragebogen, der den International Index of Erectile Function (IIEF-6 und weitere Fragen zur sexuellen Lebensqualität, zu speziellen Erkrankungen und zu verschiedenen Operationen integrierte. 2499 der Männer, die den Fragebogen komplett ausfüllten, lebten in einer Partnerschaft und bildeten die Studiengruppe dieser Untersuchung. Anhand des IIEF-6 wurden 2 Studienendpunkte definiert (Punktwerte ≤ 25/SEP1 bzw. ≤ 21/SEP2 Punkte. Mittels multivariater logistischer Regressionsmodelle wurde der unabhängige Einfluss der Zirkumzision auf die beiden SEPs geprüft. Zudem wurde die Korrelation zwischen der sexuellen Zufriedenheit des Mannes und der Zirkumzision analysiert. Ergebnisse: 167 Männer der Studiengruppe waren zirkumzidiert (6,7 %. Die erektile Dysfunktion (ED betrug im SEP1 40,1 % (leichte-schwere ED und im SEP2 27,8 % (moderate-schwere ED. Einen unabhängigen Einfluss auf die ED wiesen sowohl für den SEP1 als auch den SEP2 die Kriterien Alter, Raucheranamnese, arterielle Hypertonie, Diabetes mellitus, chronisch-ischämische Herzerkrankung, periphere-arterielle Verschlusskrankheit, Leberzirrhose und Zustand nach beckenchirurgischem Eingriff auf. Die Zirkumzision zeigte keinen unabhängigen Einfluss auf die Studienendpunkte 1 (OR 1,36; p = 0,174 und 2 (OR 1,42; p = 0,175. Darüber hinaus bestand kein signifikanter Zusammenhang zwischen der sexuellen Zufriedenheit des Mannes und einer erfolgten Zirkumzision. Schlussfolgerungen: In dieser weltweit größten Fragebogenstudie zur männlichen ED, die sich des IIEF als hierfür validiertes Instrument bediente, konnte keine

  9. Organisationsaspekte in der Umsetzung

    Science.gov (United States)

    Balck, Henning; Bungard, Walter; Hofmann, Karsten; Ganz, Walter; Schwenker, Burkhard; Hanßen, Dirk; Meindl, Rudolf; Schloske, Alexander; Thieme, Paul; Teufel, Peter

    Strukturbrüche sind eine der Hauptursachen für die Schwierigkeiten vieler Unternehmen, ihre Organisationsform zu modernisieren und vor allem turbulenten Marktbedingungen anzupassen. Klassische Beispiele für Strukturbrüche finden sich in der Spaltung von Aufbau- und Ablauforganisation, der Spaltung von Produktion und Dienstleistung oder der Spaltung von Planung und Ausführung. Ein wirkungsvoller Ansatz zur Überwindung solcher Spaltungen ist eine Art Versöhnungsmuster: die Polare Organisation. Wesentliche Elemente dieser Organisationsform sind ihr Netzwerkcharakter, kooperatives Zusammenwirken, eine hohe Kommunikationsintensität und eine polare Koppelung der kommunizierenden Partner oder - in abstrahierter Form - die organisierte Balance erfolgskritischer Gegensätze, wie Kosten und Qualität.

  10. Strahlungsfeldbedingungen bei der Ionisationsdosimetrie

    Science.gov (United States)

    Krieger, Hanno

    Bei der Dosimetrie von Photonenstrahlungen mit luftgefüllten Ionisationskammern werden in diesem Kapitel zwei Grenzfälle unterschieden. Der eine Fall ist die Bedingung des so genannten Sekundärelektronengleichwichts im Kammervolumen. In diesem Fall bestimmen ausschließlich die Photonen im Messvolumen die dosimetrische Anzeige. Der zweite Grenzfall ist gegeben, wenn das Luftvolumen und die Kammer das Strahlungsfeld im Phantom so wenig stören, dass der Sekundärelektronenfluss unverändert bleibt. Diese Bedingungen nennt man BRAGG-GRAY-Bedingungen. Beide Grenzfälle sind in der Praxis nur näherungsweise zu verwirklichen. Abweichungen müssen durch entsprechende Korrekturen oder Kalibrierungen berücksichtigt werden.

  11. Ideengeschichte der Physik

    CERN Document Server

    Kuhn, Wildfried

    2016-01-01

    Die Ideengeschichte der Physik geht neue Wege, indem sie den umfangreichen historischen Stoff nicht additiv darstellt, sondern wissenschaftstheoretisch reflektiert und nach thematischen Leitlinien (Materievorstellungen, Raum und Zeit, Erhaltungskonzepte, Extremalprinzipien, Theorie und Experiment) strukturiert. Damit vermittelt diese Darstellung im historischen Kontext ein tieferes Verständnis des physikalischen Denkens von der Antike bis heute und lotet zugleich die Dimension der Genesis physikalischer Begriffe aus, die in modernen Lehrbüchern zumeist nicht dargelegt wird. Das Credo Kuhns: Wer über die handwerkliche Handhabung von Physik hinausgehen will, muss sich zwingend mit der Frage befassen, was physikalisches Denken ausmacht und wie es entstanden ist. Die vorliegende zweite Auflage wurde ergänzt durch ein Vorwort von Prof. Dr. Oliver Schwarz, der im Institut Wilfried Kuhns forschen konnte und dabei dessen Denk- und Arbeitsweisen kennengelernt hat.

  12. Entanglement dynamics in quantum information theory

    Energy Technology Data Exchange (ETDEWEB)

    Cubitt, T.S.

    2007-03-29

    This thesis contributes to the theory of entanglement dynamics, that is, the behaviour of entanglement in systems that are evolving with time. Progressively more complex multipartite systems are considered, starting with low-dimensional tripartite systems, whose entanglement dynamics can nonetheless display surprising properties, progressing through larger networks of interacting particles, and finishing with infinitely large lattice models. Firstly, what is perhaps the most basic question in entanglement dynamics is considered: what resources are necessary in order to create entanglement between distant particles? The answer is surprising: sending separable states between the parties is sufficient; entanglement can be created without it being carried by a ''messenger'' particle. The analogous result also holds in the continuous-time case: two particles interacting indirectly via a common ancilla particle can be entangled without the ancilla ever itself becoming entangled. The latter result appears to discount any notion of entanglement flow. However, for pure states, this intuitive idea can be recovered, and even made quantitative. A ''bottleneck'' inequality is derived that relates the entanglement rate of the end particles in a tripartite chain to the entanglement of the middle one. In particular, no entanglement can be created if the middle particle is not entangled. However, although this result can be applied to general interaction networks, it does not capture the full entanglement dynamics of these more complex systems. This is remedied by the derivation of entanglement rate equations, loosely analogous to the rate equations describing a chemical reaction. A complete set of rate equations for a system reflects the full structure of its interaction network, and can be used to prove a lower bound on the scaling with chain length of the time required to entangle the ends of a chain. Finally, in contrast with these more

  13. Entanglement dynamics in quantum information theory

    International Nuclear Information System (INIS)

    Cubitt, T.S.

    2007-01-01

    This thesis contributes to the theory of entanglement dynamics, that is, the behaviour of entanglement in systems that are evolving with time. Progressively more complex multipartite systems are considered, starting with low-dimensional tripartite systems, whose entanglement dynamics can nonetheless display surprising properties, progressing through larger networks of interacting particles, and finishing with infinitely large lattice models. Firstly, what is perhaps the most basic question in entanglement dynamics is considered: what resources are necessary in order to create entanglement between distant particles? The answer is surprising: sending separable states between the parties is sufficient; entanglement can be created without it being carried by a ''messenger'' particle. The analogous result also holds in the continuous-time case: two particles interacting indirectly via a common ancilla particle can be entangled without the ancilla ever itself becoming entangled. The latter result appears to discount any notion of entanglement flow. However, for pure states, this intuitive idea can be recovered, and even made quantitative. A ''bottleneck'' inequality is derived that relates the entanglement rate of the end particles in a tripartite chain to the entanglement of the middle one. In particular, no entanglement can be created if the middle particle is not entangled. However, although this result can be applied to general interaction networks, it does not capture the full entanglement dynamics of these more complex systems. This is remedied by the derivation of entanglement rate equations, loosely analogous to the rate equations describing a chemical reaction. A complete set of rate equations for a system reflects the full structure of its interaction network, and can be used to prove a lower bound on the scaling with chain length of the time required to entangle the ends of a chain. Finally, in contrast with these more abstract results, the entanglement and

  14. Entanglement rules for holographic Fermi surfaces

    Directory of Open Access Journals (Sweden)

    Dibakar Roychowdhury

    2016-08-01

    Full Text Available In this paper, based on the notion of Gauge/Gravity duality, we explore the laws of entanglement thermodynamics for most generic classes of Quantum Field Theories with hyperscaling violation. In our analysis, we note that for Quantum Field Theories with compressible quark like excitation, the first law of entanglement thermodynamics gets modified due to the presence of an additional term that could be identified as the entanglement chemical potential associated with hidden Fermi surfaces of the boundary theory. Most notably, we find that the so called entanglement chemical potential does not depend on the size of the entangling region and is purely determined by the quark d.o.f. encoded within the entangling region.

  15. Entanglement between two spatially separated atomic modes

    Science.gov (United States)

    Lange, Karsten; Peise, Jan; Lücke, Bernd; Kruse, Ilka; Vitagliano, Giuseppe; Apellaniz, Iagoba; Kleinmann, Matthias; Tóth, Géza; Klempt, Carsten

    2018-04-01

    Modern quantum technologies in the fields of quantum computing, quantum simulation, and quantum metrology require the creation and control of large ensembles of entangled particles. In ultracold ensembles of neutral atoms, nonclassical states have been generated with mutual entanglement among thousands of particles. The entanglement generation relies on the fundamental particle-exchange symmetry in ensembles of identical particles, which lacks the standard notion of entanglement between clearly definable subsystems. Here, we present the generation of entanglement between two spatially separated clouds by splitting an ensemble of ultracold identical particles prepared in a twin Fock state. Because the clouds can be addressed individually, our experiments open a path to exploit the available entangled states of indistinguishable particles for quantum information applications.

  16. Entanglement rules for holographic Fermi surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Roychowdhury, Dibakar, E-mail: dibakarphys@gmail.com

    2016-08-15

    In this paper, based on the notion of Gauge/Gravity duality, we explore the laws of entanglement thermodynamics for most generic classes of Quantum Field Theories with hyperscaling violation. In our analysis, we note that for Quantum Field Theories with compressible quark like excitation, the first law of entanglement thermodynamics gets modified due to the presence of an additional term that could be identified as the entanglement chemical potential associated with hidden Fermi surfaces of the boundary theory. Most notably, we find that the so called entanglement chemical potential does not depend on the size of the entangling region and is purely determined by the quark d.o.f. encoded within the entangling region.

  17. Entanglement criteria for microscopic-macroscopic systems

    International Nuclear Information System (INIS)

    Spagnolo, Nicolo; Vitelli, Chiara; Sciarrino, Fabio; De Martini, Francesco

    2010-01-01

    We discuss the conclusions that can be drawn on a recent experimental micro-macro entanglement test [De Martini, Sciarrino, and Vitelli, Phys. Rev. Lett. 100, 253601 (2008)]. The system under investigation is generated through optical parametric amplification of one photon belonging to an entangled pair. The adopted entanglement criterion makes it possible to infer the presence of entanglement before losses that occur on the macrostate under a specific assumption. In particular, an a priori knowledge of the system that generates the micro-macro pair is necessary to exclude a class of separable states that can reproduce the obtained experimental results. Finally, we discuss the feasibility of a micro-macro ''genuine'' entanglement test on the analyzed system by considering different strategies, which show that in principle a fraction ε, proportional to the number of photons that survive the lossy process, of the original entanglement persists in any loss regime.

  18. Entangled photons and quantum communication

    Energy Technology Data Exchange (ETDEWEB)

    Yuan Zhensheng, E-mail: yuanzs@ustc.edu.c [Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Physikalisches Institut, Universitaet Heidelberg, Philosophenweg 12, 69120 Heidelberg (Germany); Bao Xiaohui [Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Physikalisches Institut, Universitaet Heidelberg, Philosophenweg 12, 69120 Heidelberg (Germany); Lu Chaoyang; Zhang Jun; Peng Chengzhi [Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Pan Jianwei, E-mail: pan@ustc.edu.c [Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Physikalisches Institut, Universitaet Heidelberg, Philosophenweg 12, 69120 Heidelberg (Germany)

    2010-12-15

    This article reviews the progress of quantum communication that utilizes photonic entanglement. We start with a survey of various methods for generating entangled photons, followed by an introduction of the theoretical principles and the experimental implementations of quantum key distribution. We then move on to a discussion of more involved quantum communication protocols including quantum dense coding, teleportation and quantum communication complexity. After that, we review the progress in free-space quantum communication, decoherence-free subspace, and quantum repeater protocols which are essential ingredients for long-distance quantum communication. Practical realizations of quantum repeaters, which require an interface between photons and quantum memories, are discussed briefly. Finally, we draw concluding remarks considering the technical challenges, and put forward an outlook on further developments of this field.

  19. Quantum steganography using prior entanglement

    International Nuclear Information System (INIS)

    Mihara, Takashi

    2015-01-01

    Steganography is the hiding of secret information within innocent-looking information (e.g., text, audio, image, video, etc.). A quantum version of steganography is a method based on quantum physics. In this paper, we propose quantum steganography by combining quantum error-correcting codes with prior entanglement. In many steganographic techniques, embedding secret messages in error-correcting codes may cause damage to them if the embedded part is corrupted. However, our proposed steganography can separately create secret messages and the content of cover messages. The intrinsic form of the cover message does not have to be modified for embedding secret messages. - Highlights: • Our steganography combines quantum error-correcting codes with prior entanglement. • Our steganography can separately create secret messages and the content of cover messages. • Errors in cover messages do not have affect the recovery of secret messages. • We embed a secret message in the Steane code as an example of our steganography

  20. Quantum steganography using prior entanglement

    Energy Technology Data Exchange (ETDEWEB)

    Mihara, Takashi, E-mail: mihara@toyo.jp

    2015-06-05

    Steganography is the hiding of secret information within innocent-looking information (e.g., text, audio, image, video, etc.). A quantum version of steganography is a method based on quantum physics. In this paper, we propose quantum steganography by combining quantum error-correcting codes with prior entanglement. In many steganographic techniques, embedding secret messages in error-correcting codes may cause damage to them if the embedded part is corrupted. However, our proposed steganography can separately create secret messages and the content of cover messages. The intrinsic form of the cover message does not have to be modified for embedding secret messages. - Highlights: • Our steganography combines quantum error-correcting codes with prior entanglement. • Our steganography can separately create secret messages and the content of cover messages. • Errors in cover messages do not have affect the recovery of secret messages. • We embed a secret message in the Steane code as an example of our steganography.

  1. Experimental quantum computing without entanglement.

    Science.gov (United States)

    Lanyon, B P; Barbieri, M; Almeida, M P; White, A G

    2008-11-14

    Deterministic quantum computation with one pure qubit (DQC1) is an efficient model of computation that uses highly mixed states. Unlike pure-state models, its power is not derived from the generation of a large amount of entanglement. Instead it has been proposed that other nonclassical correlations are responsible for the computational speedup, and that these can be captured by the quantum discord. In this Letter we implement DQC1 in an all-optical architecture, and experimentally observe the generated correlations. We find no entanglement, but large amounts of quantum discord-except in three cases where an efficient classical simulation is always possible. Our results show that even fully separable, highly mixed, states can contain intrinsically quantum mechanical correlations and that these could offer a valuable resource for quantum information technologies.

  2. Entangled photons and quantum communication

    International Nuclear Information System (INIS)

    Yuan Zhensheng; Bao Xiaohui; Lu Chaoyang; Zhang Jun; Peng Chengzhi; Pan Jianwei

    2010-01-01

    This article reviews the progress of quantum communication that utilizes photonic entanglement. We start with a survey of various methods for generating entangled photons, followed by an introduction of the theoretical principles and the experimental implementations of quantum key distribution. We then move on to a discussion of more involved quantum communication protocols including quantum dense coding, teleportation and quantum communication complexity. After that, we review the progress in free-space quantum communication, decoherence-free subspace, and quantum repeater protocols which are essential ingredients for long-distance quantum communication. Practical realizations of quantum repeaters, which require an interface between photons and quantum memories, are discussed briefly. Finally, we draw concluding remarks considering the technical challenges, and put forward an outlook on further developments of this field.

  3. Quantum entanglement at negative temperature

    International Nuclear Information System (INIS)

    Furman, G B; Meerovich, V M; Sokolovsky, V L

    2013-01-01

    An isolated spin system that is in internal thermodynamic equilibrium and that has an upper limit to its allowed energy states can possess a negative temperature. We calculate the thermodynamic characteristics and the concurrence in this system over the entire range of positive and negative temperatures. Our calculation was performed for different real structures, which can be used in experiments. It is found that the temperature dependence of the concurrence is substantially asymmetrical similarly to other thermodynamic characteristics. At a negative temperature the maximum concurrence and the absolute temperature of the entanglement appearance are significantly larger than those at a positive temperature. The concurrence can be characterized by two dimensionless parameters: the ratio between the Zeeman and dipolar energies and the ratio of the thermal and dipolar energies. It was shown that for all considered structures the dimensionless temperatures of the transition between entanglement and separability of the first and second spins are independent of spin structure and the number of spins. (paper)

  4. Increasing Entanglement between Gaussian States by Coherent Photon Subtraction

    DEFF Research Database (Denmark)

    Ourjoumtsev, Alexei; Dantan, Aurelien Romain; Tualle Brouri, Rosa

    2007-01-01

    We experimentally demonstrate that the entanglement between Gaussian entangled states can be increased by non-Gaussian operations. Coherent subtraction of single photons from Gaussian quadrature-entangled light pulses, created by a nondegenerate parametric amplifier, produces delocalized states...

  5. Van der Waals phase transition in the framework of holography

    International Nuclear Information System (INIS)

    Zeng, Xiao-Xiong; Li, Li-Fang

    2017-01-01

    Phase structure of the quintessence Reissner–Nordström–AdS black hole is probed by the nonlocal observables such as holographic entanglement entropy and two point correlation function. Our result shows that, as the case of the thermal entropy, both the observables exhibit the Van der Waals-like phase transition. To reinforce this conclusion, we further check the equal area law for the first order phase transition and critical exponent of the heat capacity for the second order phase transition. We also discuss the effect of the state parameter on the phase structure of the nonlocal observables.

  6. Van der Waals phase transition in the framework of holography

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Xiao-Xiong, E-mail: xxzeng@itp.ac.cn [State School of Material Science and Engineering, Chongqing Jiaotong University, Chongqing 400074 (China); Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China); Li, Li-Fang, E-mail: lilf@itp.ac.cn [State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing 100190 (China)

    2017-01-10

    Phase structure of the quintessence Reissner–Nordström–AdS black hole is probed by the nonlocal observables such as holographic entanglement entropy and two point correlation function. Our result shows that, as the case of the thermal entropy, both the observables exhibit the Van der Waals-like phase transition. To reinforce this conclusion, we further check the equal area law for the first order phase transition and critical exponent of the heat capacity for the second order phase transition. We also discuss the effect of the state parameter on the phase structure of the nonlocal observables.

  7. Van der Waals phase transition in the framework of holography

    Directory of Open Access Journals (Sweden)

    Xiao-Xiong Zeng

    2017-01-01

    Full Text Available Phase structure of the quintessence Reissner–Nordström–AdS black hole is probed by the nonlocal observables such as holographic entanglement entropy and two point correlation function. Our result shows that, as the case of the thermal entropy, both the observables exhibit the Van der Waals-like phase transition. To reinforce this conclusion, we further check the equal area law for the first order phase transition and critical exponent of the heat capacity for the second order phase transition. We also discuss the effect of the state parameter on the phase structure of the nonlocal observables.

  8. Quantify entanglement by concurrence hierarchy

    OpenAIRE

    Fan, Heng; Matsumoto, Keiji; Imai, Hiroshi

    2002-01-01

    We define the concurrence hierarchy as d-1 independent invariants under local unitary transformations in d-level quantum system. The first one is the original concurrence defined by Wootters et al in 2-level quantum system and generalized to d-level pure quantum states case. We propose to use this concurrence hierarchy as measurement of entanglement. This measurement does not increase under local quantum operations and classical communication.

  9. Entanglement, holography and causal diamonds

    Energy Technology Data Exchange (ETDEWEB)

    Boer, Jan de [Institute of Physics, Universiteit van Amsterdam,Science Park 904, 1090 GL Amsterdam (Netherlands); Haehl, Felix M. [Centre for Particle Theory & Department of Mathematical Sciences, Durham University,South Road, Durham DH1 3LE (United Kingdom); Heller, Michal P.; Myers, Robert C. [Perimeter Institute for Theoretical Physics,31 Caroline Street North, Waterloo, Ontario N2L 2Y5 (Canada)

    2016-08-29

    We argue that the degrees of freedom in a d-dimensional CFT can be re-organized in an insightful way by studying observables on the moduli space of causal diamonds (or equivalently, the space of pairs of timelike separated points). This 2d-dimensional space naturally captures some of the fundamental nonlocality and causal structure inherent in the entanglement of CFT states. For any primary CFT operator, we construct an observable on this space, which is defined by smearing the associated one-point function over causal diamonds. Known examples of such quantities are the entanglement entropy of vacuum excitations and its higher spin generalizations. We show that in holographic CFTs, these observables are given by suitably defined integrals of dual bulk fields over the corresponding Ryu-Takayanagi minimal surfaces. Furthermore, we explain connections to the operator product expansion and the first law of entanglement entropy from this unifying point of view. We demonstrate that for small perturbations of the vacuum, our observables obey linear two-derivative equations of motion on the space of causal diamonds. In two dimensions, the latter is given by a product of two copies of a two-dimensional de Sitter space. For a class of universal states, we show that the entanglement entropy and its spin-three generalization obey nonlinear equations of motion with local interactions on this moduli space, which can be identified with Liouville and Toda equations, respectively. This suggests the possibility of extending the definition of our new observables beyond the linear level more generally and in such a way that they give rise to new dynamically interacting theories on the moduli space of causal diamonds. Various challenges one has to face in order to implement this idea are discussed.

  10. Entanglement and inhibited quantum evolution

    International Nuclear Information System (INIS)

    Toschek, P E; Balzer, Chr; Hannemann, Th; Wunderlich, Ch; Neuhauser, W

    2003-01-01

    The evolution of a quantum system is impeded by the system's state being observed. A test on an ensemble neither proves the causal nexus nor discloses the nature of the inhibition. Two recent experiments that make use of sequential optical or microwave-optical double resonance on an individual trapped ion disprove a dynamical effect of back action by meter or environment. They rather indicate the ionic states involved in the evolution being entangled with the potentially recorded bivalued scattered-light signal

  11. Spin entanglement, decoherence and Bohm's EPR paradox

    OpenAIRE

    Cavalcanti, E. G.; Drummond, P. D.; Bachor, H. A.; Reid, M. D.

    2007-01-01

    We obtain criteria for entanglement and the EPR paradox for spin-entangled particles and analyse the effects of decoherence caused by absorption and state purity errors. For a two qubit photonic state, entanglement can occur for all transmission efficiencies. In this case, the state preparation purity must be above a threshold value. However, Bohm's spin EPR paradox can be achieved only above a critical level of loss. We calculate a required efficiency of 58%, which appears achievable with cu...

  12. Gaussian maximally multipartite-entangled states

    Science.gov (United States)

    Facchi, Paolo; Florio, Giuseppe; Lupo, Cosmo; Mancini, Stefano; Pascazio, Saverio

    2009-12-01

    We study maximally multipartite-entangled states in the context of Gaussian continuous variable quantum systems. By considering multimode Gaussian states with constrained energy, we show that perfect maximally multipartite-entangled states, which exhibit the maximum amount of bipartite entanglement for all bipartitions, only exist for systems containing n=2 or 3 modes. We further numerically investigate the structure of these states and their frustration for n≤7 .

  13. Gaussian maximally multipartite-entangled states

    International Nuclear Information System (INIS)

    Facchi, Paolo; Florio, Giuseppe; Pascazio, Saverio; Lupo, Cosmo; Mancini, Stefano

    2009-01-01

    We study maximally multipartite-entangled states in the context of Gaussian continuous variable quantum systems. By considering multimode Gaussian states with constrained energy, we show that perfect maximally multipartite-entangled states, which exhibit the maximum amount of bipartite entanglement for all bipartitions, only exist for systems containing n=2 or 3 modes. We further numerically investigate the structure of these states and their frustration for n≤7.

  14. Variation of entanglement entropy in scattering process

    Energy Technology Data Exchange (ETDEWEB)

    Seki, Shigenori, E-mail: sigenori@hanyang.ac.kr [Research Institute for Natural Science, Hanyang University, Seoul 133-791 (Korea, Republic of); Park, I.Y., E-mail: inyongpark05@gmail.com [Department of Applied Mathematics, Philander Smith College, Little Rock, AR 72223 (United States); Sin, Sang-Jin, E-mail: sjsin@hanyang.ac.kr [Department of Physics, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2015-04-09

    In a scattering process, the final state is determined by an initial state and an S-matrix. We focus on two-particle scattering processes and consider the entanglement between these particles. For two types initial states, i.e., an unentangled state and an entangled one, we calculate perturbatively the change of entanglement entropy from the initial state to the final one. Then we show a few examples in a field theory and in quantum mechanics.

  15. Hybrid Long-Distance Entanglement Distribution Protocol

    DEFF Research Database (Denmark)

    Brask, J.B.; Rigas, I.; Polzik, E.S.

    2010-01-01

    We propose a hybrid (continuous-discrete variable) quantum repeater protocol for long-distance entanglement distribution. Starting from states created by single-photon detection, we show how entangled coherent state superpositions can be generated by means of homodyne detection. We show that near......-deterministic entanglement swapping with such states is possible using only linear optics and homodyne detectors, and we evaluate the performance of our protocol combining these elements....

  16. Controllable entanglement sudden birth of Heisenberg spins

    International Nuclear Information System (INIS)

    Zheng Qiang; Zhi Qijun; Zhang Xiaoping; Ren Zhongzhou

    2011-01-01

    We investigate the Entanglement Sudden Birth (ESB) of two Heisenberg spins A and B. The third controller, qutrit C is introduced, which only has the Dzyaloshinskii-Moriya (DM) spin-orbit interaction with qubit B. We find that the DM interaction is necessary to induce the Entanglement Sudden Birth of the system qubits A and B, and the initial states of the system qubits and the qutrit C are also important to control its Entanglement Sudden Birth. (authors)

  17. Experimental generation of complex noisy photonic entanglement

    International Nuclear Information System (INIS)

    Dobek, K; Banaszek, K; Karpiński, M; Demkowicz-Dobrzański, R; Horodecki, P

    2013-01-01

    We present an experimental scheme based on spontaneous parametric down-conversion to produce multiple-photon pairs in maximally entangled polarization states using an arrangement of two type-I nonlinear crystals. By introducing correlated polarization noise in the paths of the generated photons we prepare mixed-entangled states whose properties illustrate fundamental results obtained recently in quantum information theory, in particular those concerning bound entanglement and privacy. (paper)

  18. Quantum dialogue using non-maximally entangled states based on entanglement swapping

    International Nuclear Information System (INIS)

    Xia Yan; Song Jie; Song Heshan

    2007-01-01

    We present a secure quantum dialogue protocol using non-maximally entangled two-particle states via entanglement swapping at first, and then discuss the requirements for a real quantum dialogue. Within the present version two authorized users can exchange their faithful secret messages securely and simultaneously based on the method of entanglement purification

  19. Time evolution of the Wigner function in the entangled-state representation

    International Nuclear Information System (INIS)

    Fan Hongyi

    2002-01-01

    For quantum-mechanical entangled states we introduce the entangled Wigner operator in the entangled-state representation. We derive the time evolution equation of the entangled Wigner operator . The trace product rule for entangled Wigner functions is also obtained

  20. Entanglement dynamics in random media

    Science.gov (United States)

    Menezes, G.; Svaiter, N. F.; Zarro, C. A. D.

    2017-12-01

    We study how the entanglement dynamics between two-level atoms is impacted by random fluctuations of the light cone. In our model the two-atom system is envisaged as an open system coupled with an electromagnetic field in the vacuum state. We employ the quantum master equation in the Born-Markov approximation in order to describe the completely positive time evolution of the atomic system. We restrict our investigations to the situation in which the atoms are coupled individually to two spatially separated cavities, one of which displays the emergence of light-cone fluctuations. In such a disordered cavity, we assume that the coefficients of the Klein-Gordon equation are random functions of the spatial coordinates. The disordered medium is modeled by a centered, stationary, and Gaussian process. We demonstrate that disorder has the effect of slowing down the entanglement decay. We conjecture that in a strong-disorder environment the mean life of entangled states can be enhanced in such a way as to almost completely suppress quantum nonlocal decoherence.

  1. Minimal tomography with entanglement witnesses

    International Nuclear Information System (INIS)

    Zhu Huangjun; Teo Yong Siah; Englert, Berthold-Georg

    2010-01-01

    We introduce informationally complete measurements whose outcomes are entanglement witnesses and so answer the question of how many witnesses need to be measured to decide whether an arbitrary state is entangled or not: as many as the dimension of the state space. The witnesses can be measured successively; if all of them give an inconclusive result, one exploits their tomographic completeness for a reconstruction of the quantum state and can then determine its entanglement properties by data processing. There are witnesses that are optimal for this purpose. The optimized witness-based measurement can provide exponential improvement with respect to witness efficiency in high-dimensional Hilbert spaces, at the price of a reduction in the tomographic efficiency. We describe a systematic construction and illustrate the matter with the example of two qubits. For the case of two polarization qubits of photons, we show how existing technology can be used to implement the optimized witnesses in a very efficient way. Owing to the details of the implementation, which actually measures the eigenstate basis of the witness rather than solely determining the expectation value of the witness, one does not need to measure more than six witnesses in this example of a 16-dimensional state space.

  2. Minimal tomography with entanglement witnesses

    Science.gov (United States)

    Zhu, Huangjun; Teo, Yong Siah; Englert, Berthold-Georg

    2010-05-01

    We introduce informationally complete measurements whose outcomes are entanglement witnesses and so answer the question of how many witnesses need to be measured to decide whether an arbitrary state is entangled or not: as many as the dimension of the state space. The witnesses can be measured successively; if all of them give an inconclusive result, one exploits their tomographic completeness for a reconstruction of the quantum state and can then determine its entanglement properties by data processing. There are witnesses that are optimal for this purpose. The optimized witness-based measurement can provide exponential improvement with respect to witness efficiency in high-dimensional Hilbert spaces, at the price of a reduction in the tomographic efficiency. We describe a systematic construction and illustrate the matter with the example of two qubits. For the case of two polarization qubits of photons, we show how existing technology can be used to implement the optimized witnesses in a very efficient way. Owing to the details of the implementation, which actually measures the eigenstate basis of the witness rather than solely determining the expectation value of the witness, one does not need to measure more than six witnesses in this example of a 16-dimensional state space.

  3. Research of the fluid flow in a radially orientated coolant channel of a turbine blade; Untersuchung der Stroemung in einem radial gerichteten Kuehlkanal eines Turbinenlaufrades

    Energy Technology Data Exchange (ETDEWEB)

    Hein, O.

    1999-07-01

    Due to rotation (Coriolis forces) in a coolant channel a secondary flow is superimposed to the basic flow. This leads to a change in the local heat transfer over the surface of the coolant channel as well as a change in the overall value of the heat transfer. Also the pressure loss over the channel length will change by rotation. By means of computational fluid dynamics (Finite Element Method) it was achieved to figure out the interaction between changing fluid flow and heat transfer. To validate the results obtained by a numerical flow simulation, a new measurement technique was developed. A laser-two-focus velocimeter has been combined with a rotation prism which allows continued measurements in a rotating scaled up channel. (orig.) [German] Bedingt durch die Rotationsbewegung eines Kuehlkanals wird die Grundstroemung von einem Sekundaerwirbel ueberlagert (Corioliskraefte). Durch diese Einfluesse aendert sich sowohl der lokale Waermeuebergang ueber der Kanaloberflaeche als auch die globalen Waermeuebertragungsraten ueber dem gesamten Kanal. Ebenfalls aendert sich durch die Rotation der Druckverlust ueber der Kanallaenge. Durch eine numerische Stroemungssimulation (Finite-Element-Methode) war es moeglich, einen detaillierten Zusammenhang zwischen dem veraenderten Stroemungsverhalten und dem Waermeuebertragungsverhalten darzustellen. Um die numerisch gewonnenen Ergebnisse experimentell abzusichern, wurde eine neuartige Messtechnik entwickelt. Ein Laser-2-Fokus-Velozimeter wurde mit einem Bilddrehprisma kombiniert, und dies erlaubte eine kontinuierliche Messung in einem rotierenden vergroesserten Modellkanal. (orig.)

  4. Entanglement Swapping in the Presence of White and Color Noise

    Science.gov (United States)

    Dotsenko, Ivan S.; Korobka, R.

    2018-02-01

    The influence of white and color noise on the outcome of the entanglement swapping process is investigated in a four-qubit system. Critical degree of noise in initial state, that could destroy entanglement in a result state is presented. The entanglement characteristics, such as concurrence, tangle, etc. are compared. Results could be helpful for experiments regarding entanglement swapping as conditions for initial quantum entangled states, to obtain entangled result state.

  5. Entanglement property in matrix product spin systems

    International Nuclear Information System (INIS)

    Zhu Jingmin

    2012-01-01

    We study the entanglement property in matrix product spin-ring systems systemically by von Neumann entropy. We find that: (i) the Hilbert space dimension of one spin determines the upper limit of the maximal value of the entanglement entropy of one spin, while for multiparticle entanglement entropy, the upper limit of the maximal value depends on the dimension of the representation matrices. Based on the theory, we can realize the maximum of the entanglement entropy of any spin block by choosing the appropriate control parameter values. (ii) When the entanglement entropy of one spin takes its maximal value, the entanglement entropy of an asymptotically large spin block, i.e. the renormalization group fixed point, is not likely to take its maximal value, and so only the entanglement entropy S n of a spin block that varies with size n can fully characterize the spin-ring entanglement feature. Finally, we give the entanglement dynamics, i.e. the Hamiltonian of the matrix product system. (author)

  6. Quantum communication using a multiqubit entangled channel

    Energy Technology Data Exchange (ETDEWEB)

    Ghose, Shohini, E-mail: sghose@wlu.ca [Department of Physics and Computer Science, Wilfrid Laurier University, Waterloo, Ontario (Canada); Institute for Quantum Computing, University of Waterloo, Ontario (Canada); Hamel, Angele [Department of Physics and Computer Science, Wilfrid Laurier University, Waterloo, Ontario (Canada)

    2015-12-31

    We describe a protocol in which two senders each teleport a qubit to a receiver using a multiqubit entangled state. The multiqubit channel used for teleportation is genuinely 4-qubit entangled and is not equivalent to a product of maximally entangled Bell pairs under local unitary operations. We discuss a scenario in which both senders must participate for the qubits to be successfully teleported. Such an all-or-nothing scheme cannot be implemented with standard two-qubit entangled Bell pairs and can be useful for different communication and computing tasks.

  7. Entanglement polygon inequality in qubit systems

    Science.gov (United States)

    Qian, Xiao-Feng; Alonso, Miguel A.; Eberly, J. H.

    2018-06-01

    We prove a set of tight entanglement inequalities for arbitrary N-qubit pure states. By focusing on all bi-partite marginal entanglements between each single qubit and its remaining partners, we show that the inequalities provide an upper bound for each marginal entanglement, while the known monogamy relation establishes the lower bound. The restrictions and sharing properties associated with the inequalities are further analyzed with a geometric polytope approach, and examples of three-qubit GHZ-class and W-class entangled states are presented to illustrate the results.

  8. Entanglement Equilibrium and the Einstein Equation.

    Science.gov (United States)

    Jacobson, Ted

    2016-05-20

    A link between the semiclassical Einstein equation and a maximal vacuum entanglement hypothesis is established. The hypothesis asserts that entanglement entropy in small geodesic balls is maximized at fixed volume in a locally maximally symmetric vacuum state of geometry and quantum fields. A qualitative argument suggests that the Einstein equation implies the validity of the hypothesis. A more precise argument shows that, for first-order variations of the local vacuum state of conformal quantum fields, the vacuum entanglement is stationary if and only if the Einstein equation holds. For nonconformal fields, the same conclusion follows modulo a conjecture about the variation of entanglement entropy.

  9. Der mediale Habitus in der frühen Kindheit

    Directory of Open Access Journals (Sweden)

    Christian Swertz

    2014-12-01

    Full Text Available Die empirische Untersuchung der Medienkultur 3- bis 6-jähriger Kindergartenkinder steht im Mittelpunkt des Beitrags. Zum Verständnis der Medienkultur wird der Begriff des medialen Habitus verwendet. Die Ergebnisse zeigen, dass der Begriff des me-dialen Habitus geeignet ist, um die Medienkultur 3- bis 6-Jähriger zu verstehen, und dass der Ausdruck des medialen Habitus mit einem triangulativen qualitativen Design erfasst werden kann.

  10. Die Mythen von der Globalisierung

    DEFF Research Database (Denmark)

    Nell, Phillip; Schmitt, Jan; Decreton, Benoit

    2017-01-01

    Der Wissensstand über den Grad und die Art der Globalisierung ist viel niedriger als angenommen. Daraus entstehen Fehleinschätzungen.......Der Wissensstand über den Grad und die Art der Globalisierung ist viel niedriger als angenommen. Daraus entstehen Fehleinschätzungen....

  11. Der Weg von der Computerkompetenz zur Medienkompetenz

    Directory of Open Access Journals (Sweden)

    Barbara Zuliani

    2011-09-01

    Full Text Available Weiterführende Gedanken zur „Schlüsselkompetenz Nr.4“ des Europäischen Rates im Bereich des lebenslangen Lernens: Computerkompetenz bzw. Medienkompetenz, sowie Anwendungsbeispiele aus dem Bereich der Volksschule: Klassenblog und verschiedener Apps via iPad - 2 Praxisberichte

  12. Lesekompetenz im Französisch als 1. und 2. Fremdsprache in einer mehrsprachigen Perspektive bei Primarschüler/innen am Ende der 6. Klasse

    Directory of Open Access Journals (Sweden)

    Giuseppe Manno

    2017-04-01

    Full Text Available Im Beitrag werden Resultate eines laufenden Forschungsprojekts vorgestellt, das die Lesekompetenz im Französisch als 1. und 2. Fremdsprache (Umkehrung der bisherigen Reihenfolge durch die Fremdsprachenreform in der Schweiz unter Berücksichtigung der Schulsprache Deutsch in einer mehrsprachigen Perspektive am Ende der Primarstufe (6. Klasse untersucht. Die zentrale Fragestellung ist, ob die Schüler/innen mit Französisch als 1. Fremdsprache über eine bessere Lesekompetenz verfügen als mit Französisch als 2. Fremdsprache (jeweiliger Beginn: 5. Klasse. Des Weiteren wird der Zusammenhang zwischen der Französischlesekompetenz und der Schulsprache untersucht. Für die Überprüfung dieser Fragestellungen liegt ein quasi-experimentelles Design vor, bei dem beide Gruppen zeitverschoben gemessen wurden. In this article we will present some results of an ongoing project which studies the reading comprehension in French at the end of primary school (6th grade as first and as second foreign language (reversal of the previous order in the current reform of the foreign languages in Switzerland by also considering the school language (German within a multilingual approach. The focus of this article is whether learners with French as second foreign language reach a higher proficiency than learners with French as first foreign language (French being still taught from grade 5 on. Furthermore we will study the correlation between the reading comprehension proficiency in French and in German. The quasi-experimental research design is given by the fact that classes in the old and new system could be recorded at different times.

  13. Theoretische Konzepte der Physik

    Science.gov (United States)

    Longair, Malcolm S.; Simon, B.; Simon, H.

    "Dies ist kein Lehrbuch der theoretischen Physik, auch kein Kompendium der Physikgeschichte ... , vielmehr eine recht anspruchsvolle Sammlung historischer Miniaturen zur Vergangenheit der theoretischen Physik - ihrer "Sternstunden", wenn man so will. Frei vom Zwang, etwas Erschöpfendes vorlegen zu müssen, gelingt dem Autor etwas Seltenes: einen "lebendigen" Zugang zum Ideengebäude der modernen Physik freizulegen, ... zu zeigen, wie Physik in praxi entsteht... Als Vehikel seiner Absichten dienen dem Autor geschichtliche Fallstudien, insgesamt sieben an der Zahl. Aus ihnen extrahiert er das seiner Meinung nach Lehrhafte, dabei bestrebt, mathematische Anachronismen womöglich zu vermeiden... Als Student hätte ich mir diese gescheiten Essays zum Werden unserer heutigen physikalischen Weltsicht gewünscht. Sie sind originell, didaktisch klug und genieren sich auch nicht, von der Faszination zu sprechen, die ... von der Physik ausgeht. Unnötig darauf hinzuweisen, das sie ein gründliches "konventionelles" Studium weder ersetzen wollen noch können, sie vermögen aber, dazu zu ermuntern." #Astronomische Nachrichten (zur englischen Ausgabe)#1

  14. Holographic Van der Waals phase transition of the higher-dimensional electrically charged hairy black hole

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hui-Ling [University of Electronic Science and Technology of China, School of Physical Electronics, Chengdu (China); Shenyang Normal University, College of Physics Science and Technology, Shenyang (China); Feng, Zhong-Wen [China West Normal University, College of Physics and Space Science, Nanchong (China); Zu, Xiao-Tao [University of Electronic Science and Technology of China, School of Physical Electronics, Chengdu (China)

    2018-01-15

    With motivation by holography, employing black hole entropy, two-point connection function and entanglement entropy, we show that, for the higher-dimensional Anti-de Sitter charged hairy black hole in the fixed charged ensemble, a Van der Waals-like phase transition can be observed. Furthermore, based on the Maxwell equal-area construction, we check numerically the equal-area law for a first order phase transition in order to further characterize the Van der Waals-like phase transition. (orig.)

  15. Holographic Van der Waals phase transition of the higher-dimensional electrically charged hairy black hole

    International Nuclear Information System (INIS)

    Li, Hui-Ling; Feng, Zhong-Wen; Zu, Xiao-Tao

    2018-01-01

    With motivation by holography, employing black hole entropy, two-point connection function and entanglement entropy, we show that, for the higher-dimensional Anti-de Sitter charged hairy black hole in the fixed charged ensemble, a Van der Waals-like phase transition can be observed. Furthermore, based on the Maxwell equal-area construction, we check numerically the equal-area law for a first order phase transition in order to further characterize the Van der Waals-like phase transition. (orig.)

  16. On entanglement spreading from holography

    Energy Technology Data Exchange (ETDEWEB)

    Mezei, Márk [Princeton Center for Theoretical Science, Princeton University,Princeton, NJ 08544 (United States)

    2017-05-11

    A global quench is an interesting setting where we can study thermalization of subsystems in a pure state. We investigate entanglement entropy (EE) growth in global quenches in holographic field theories and relate some of its aspects to quantities characterizing chaos. More specifically we obtain four key results: We prove holographic bounds on the entanglement velocity v{sub E} and the butterfly effect speed v{sub B} that arises in the study of chaos. We obtain the EE as a function of time for large spherical entangling surfaces analytically. We show that the EE is insensitive to the details of the initial state or quench protocol. In a thermofield double state we determine analytically the two-sided mutual information between two large concentric spheres separated in time. We derive a bound on the rate of growth of EE for arbitrary shapes, and develop an expansion for EE at early times. In a companion paper https://arxiv.org/abs/1608.05101, these results are put in the broader context of EE growth in chaotic systems: we relate EE growth to the chaotic spreading of operators, derive bounds on EE at a given time, and compare the holographic results to spin chain numerics and toy models. In this paper, we perform holographic calculations that provide the basis of arguments presented in that paper. We prove holographic bounds on the entanglement velocity v{sub E} and the butterfly effect speed v{sub B} that arises in the study of chaos. We obtain the EE as a function of time for large spherical entangling surfaces analytically. We show that the EE is insensitive to the details of the initial state or quench protocol. In a thermofield double state we determine analytically the two-sided mutual information between two large concentric spheres separated in time. We derive a bound on the rate of growth of EE for arbitrary shapes, and develop an expansion for EE at early times.

  17. Teilchen, Felder, Quanten von der Quantenmechanik zum Standardmodell der Teilchenphysik

    CERN Document Server

    Ecker, Gerhard

    2017-01-01

    Dieses Buch bietet Ihnen eine Einführung in den aktuellen Stand unseres Wissens über die Struktur der Materie. Gerhard Ecker beschreibt verständlich die Entwicklung der modernen Physik vom Beginn des Quantenzeital­ters bis zum Standardmodell der Teilchenphysik, der umfassenden Theorie der fundamentalen Wechselwir­kungen des Mikrokosmos. Dabei wird der Schwerpunkt auf die wichtigsten Entdeckungen und Entwicklungen, beispielsweise der Quantenfeldtheorie, der Eichtheorien und die Zukunft der Teilchenphysik, gelegt. Besonders hebt der Autor auch das Wechselspiel zwischen Theorie und Experiment hervor, die uns helfen, die tiefsten Rätsel der Natur zu ergründen. Teilchen, Felder, Quanten ist für alle geschrieben, die Freude an der Physik haben. Es bietet Abitu­rienten und Studierenden der Physik in den ersten Semestern einen Ansporn, die Physik tiefer zu verstehen. Lehrer und andere an der Phy­sik Interessierte werden darin nützliche Einblicke in die Welt der Teilchenphysik finden. Für Studierende in ...

  18. Anticholinerge Therapie der OAB

    Directory of Open Access Journals (Sweden)

    Hampel C

    2007-01-01

    Full Text Available Kenntnisse über Differentialdiagnostik und Pathophysiologie des Blasenüberaktivitäts-Syndroms sind essentiell für eine erfolgreiche Therapie. Obwohl Verhaltenstraining und Elektrostimulation ihre Wirksamkeit bei OAB bewiesen haben, ist die Therapie der ersten Wahl nach wie vor die anticholinerge Behandlung. Dessen ungeachtet ist die Einnahmetreue der Patienten unbefriedigend, was in der letzten Zeit zu verschiedenen Medikamentenneuentwicklungen mit verbesserter Verträglichkeit bei gleichbleibend hoher Effektivität geführt hat. Retard-Formulierungen, extraenterale Applikationswege und Rezeptor-Subselektivität sind hierbei die Prinzipien, welche die Behandlungsakzeptanz und Patientenzufriedenheit steigern sollen.

  19. Der Wandel der Erwerbsformen und der Beitrag der Hartz-Reformen: Berlin und die Bundesrepublik Deutschland im Vergleich

    OpenAIRE

    Oschmiansky, Heidi

    2007-01-01

    "Seit den 1980er Jahren wird der Wandel der Erwerbsformen in der Bundesrepublik Deutschland immer stärker sichtbar. Während die sozial abgesicherte, abhängige und unbefristete Vollzeiterwerbsform - das sog. 'Normalarbeitsverhältnis' - seither leicht an Bedeutung verloren hat, zeigen sich bei den übrigen Erwerbsformen zum Teil hohe Zuwächse und eine zunehmende Differenzierung. Der vorliegende Beitrag untersucht den Wandel der Erwerbsformen zwischen 1985 und 2005 auf Basis von Mikrozensus-Daten...

  20. Der digitalisierte Steuerpflichtige

    Directory of Open Access Journals (Sweden)

    Ehrke-Rabel, Tina

    2017-12-01

    Full Text Available Der digitalisierte Steuerpflichtige ist digitalisiert in seinem Wirtschaften und digitalisiert in seiner Interaktion mit der Finanzverwaltung. Digitale und digitalisierte Wirtschaftsmodelle stellen sowohl den Gesetzgeber als auch den Abgabenvollzug vor Herausforderungen, weil einerseits die physische Anknüpfung von Sachverhalten an staatliches Territorium nahezu unmöglich wird und andererseits staatliche Kontrolle von digitalen Wirtschaftsmodellen im derzeitigen System schwer möglich ist. Halten sich Steuerpflichtige an ihre Pflichten gegenüber der Finanzverwaltung, bietet die Digitalisierung jedoch Chancen für die Effizienzsteigerung des Vollzuges. Die Balance zwischen staatlicher Effizienz durch Digitalisierung und Schutz des Einzelnen vor übermäßigen Eingriffen in das Grundrecht auf Wahrung der Privatsphäre einerseits und dem Recht auf gute Verwaltung andererseits scheint derzeit jedoch noch nicht umfassend erreicht.

  1. Fibre-optical measurement of the time curve of layer temperatures in a well as a result of heat injection and heat extraction; Untersuchung der zeitlichen Entwicklung von Schichttemperaturen in einer Bohrung bei Waermeaus- und Waermeeinspeisung mit Hilfe faseroptischer Temperaturmessungen

    Energy Technology Data Exchange (ETDEWEB)

    Hurtig, E; Groswig, S; Kasch, M [GESO GmbH, Jena (Germany)

    1997-12-01

    The relations between the thermal processes around a 200 m deep geothermal well and the petrographic composition were studied using the fibre optic temperature sensing method. The heat injection and heat extraction properties depend on the petrographic properties (porosity, permeability) of the individual layers. Coarse sandy, water saturated layers have good properties, silts and clays have poor properties for het storage and heat extraction. Heat transport occurs in well defined layers with good hydraulic properties and can be explained by a convective heat transport model. (orig.) [Deutsch] Mit faseroptischen Temperaturmessungen in einer Erdwaermesonde (EWS)-Bohrung wurde der Zusammenhang zwischen den thermischen Prozessen unmittelbar um die EWS und dem petrographischen Aufbau untersucht. Das Waermeein- bzw. -ausspeisevermoegen haengt von der petrographischen Ausbildung der einzelnen Schichten ab (Porositaet, Kf-Wert). Grobsandige bis kiesige, wassergesaettigte Schichten haben guenstige, schluffig-tonige unguenstige Eigenschaften fuer die Waermeaus- bzw. -einspeisung. Der wesentliche Waermetransport erfolgt in definierten geringmaechtigen Schichten mit guten hydraulischen Eigenschaften. Der Waermetransport in poroesen, wassergefuellten Schichten kann mit einem konvektiven Waermetransportmodell erklaert werden. (orig.)

  2. Germany must become a model for other countries. ``Sustainable consumption`` and its importance against the background of the Agenda 21; Deutschland muss fuer die anderen Laender Vorbild werden. `Nachhaltiger Konsum` und dessen Stellenwert vor dem Hintergrund der Agenda 21

    Energy Technology Data Exchange (ETDEWEB)

    Schafhausen, F. [Bundesministerium fuer Umwelt, Naturschutz und Reaktorsicherheit, Bonn (Germany)

    1998-04-01

    The ``Agenda 21`` was decided at Rio de Janeiro in June 1992. It is to provide a guideline for political action of all parties concerned in the 21st century. Its key concept, ``sustainable develoment``, is a multi-faceted concept which attempts to coordinate ecological, economic and social needs on a medium to long-term basis. Changes in consumption patterns are of central importance. The article goes into detail about these and also about the problems caused by energy and power supply as it is today. (orig.) [Deutsch] Im Juni 1992 wurde in Rio de Janeiro die sogenannten `Agenda 21` als Leitfaden fuer das im 21. Jahrhundert erforderliche Handeln aller Akteure verabschiedet. Im Zentrum dieses Aktionsprogramms steht der schillernde Begriff `sustainable development`. In vierzig Kapiteln, die sich mit allen gesellschaftlichen Gruppen und allen Problemfeldern moderner Gesellschaften auseinandersetzen, wird versucht, `nachhaltige Entwicklung` zu definieren und Wege aufzuzeigen, wie oekologische, oekonomische und gesellschaftliche Anliegen mittel- bis langfristig auf einen Nenner gebracht werden koennen. Von zentraler Bedeutung ist dabei die Frage der Veraenderung der Konsumgewohnheiten. Mit diesem Thema wird ein grosser Teil der in Rio alle Verhandlungen bestimmenden Anliegen angesprochen. Es verwundert nicht, dass auch in diesem Zusammenhang die von der heutigen Energieversorgung verursachten Probleme im Vordergrund stehen. (orig.)

  3. Praxisrelevanz der Methodenausbildung

    OpenAIRE

    2002-01-01

    'Mit dem Band werden die Beiträge namhafter Sozialforscher aus Universitäten und Markt- und Sozialforschungsinstituten zu einer Tagung veröffentlicht, die am 6./7. Juli 2001 an der Universität Bonn abgehalten wurde. Im Mittelpunkt der Tagung stand die Frage, ob die derzeitige Ausbildung in Methoden empirischer Sozialforschung und Statistik den beruflichen Anforderungen in Universitäten sowie akademischen und privatwirtschaftlich verfassten Forschungsinstituten gerecht wird. Gestützt auf Erfah...

  4. Lexikon der bulgarischen Alltagsgesten

    OpenAIRE

    Kolarova, Zornitza

    2012-01-01

    Die vorliegende Dissertation untersucht die Alltagsgesten der Bulgaren. Das Lexikon der bulgarischen Alltagsgesten umfasst 56 Embleme, die derzeit in Bulgarien benutzt werden und die nicht weltweit und nicht in Nord-und Westeuropa verbreitet sind. Auch solche Gesten, die in Westeuropa bekannt sind, aber in Bulgarien einen oder mehrere morphologische oder semantische Unterschiede aufweisen, wurden in getrennten Einträgen beschrieben. Die Gesten werden in Gestenfamilien – einer Reihe ausdrucksv...

  5. Two particle entanglement and its geometric duals

    Energy Technology Data Exchange (ETDEWEB)

    Wasay, Muhammad Abdul [University of Agriculture, Department of Physics, Faisalabad (Pakistan); Quaid-i-Azam University Campus, National Centre for Physics, Islamabad (Pakistan); Bashir, Asma [University of Agriculture, Department of Physics, Faisalabad (Pakistan)

    2017-12-15

    We show that for a system of two entangled particles, there is a dual description to the particle equations in terms of classical theory of conformally stretched spacetime. We also connect these entangled particle equations with Finsler geometry. We show that this duality translates strongly coupled quantum equations in the pilot-wave limit to weakly coupled geometric equations. (orig.)

  6. Generating stationary entangled states in superconducting qubits

    International Nuclear Information System (INIS)

    Zhang Jing; Liu Yuxi; Li Chunwen; Tarn, T.-J.; Nori, Franco

    2009-01-01

    When a two-qubit system is initially maximally entangled, two independent decoherence channels, one per qubit, would greatly reduce the entanglement of the two-qubit system when it reaches its stationary state. We propose a method on how to minimize such a loss of entanglement in open quantum systems. We find that the quantum entanglement of general two-qubit systems with controllable parameters can be controlled by tuning both the single-qubit parameters and the two-qubit coupling strengths. Indeed, the maximum fidelity F max between the stationary entangled state, ρ ∞ , and the maximally entangled state, ρ m , can be about 2/3≅max(tr(ρ ∞ ρ m ))=F max , corresponding to a maximum stationary concurrence, C max , of about 1/3≅C(ρ ∞ )=C max . This is significant because the quantum entanglement of the two-qubit system can be produced and kept, even for a long time. We apply our proposal to several types of two-qubit superconducting circuits and show how the entanglement of these two-qubit circuits can be optimized by varying experimentally controllable parameters.

  7. Rank-dependant factorization of entanglement evolution

    International Nuclear Information System (INIS)

    Siomau, Michael

    2016-01-01

    Highlights: • In some cases the complex entanglement evolution can be factorized on simple terms. • We suggest factorization equations for multiqubit entanglement evolution. • The factorization is solely defined by the rank of the final state density matrices. • The factorization is independent on the local noisy channels and initial pure states. - Abstract: The description of the entanglement evolution of a complex quantum system can be significantly simplified due to the symmetries of the initial state and the quantum channels, which simultaneously affect parts of the system. Using concurrence as the entanglement measure, we study the entanglement evolution of few qubit systems, when each of the qubits is affected by a local unital channel independently on the others. We found that for low-rank density matrices of the final quantum state, such complex entanglement dynamics can be completely described by a combination of independent factors representing the evolution of entanglement of the initial state, when just one of the qubits is affected by a local channel. We suggest necessary conditions for the rank of the density matrices to represent the entanglement evolution through the factors. Our finding is supported with analytical examples and numerical simulations.

  8. On entanglement in neutrino mixing and oscillations

    International Nuclear Information System (INIS)

    Blasone, Massimo; Dell'Anno, Fabio; De Siena, Silvio; Illuminati, Fabrizio

    2010-01-01

    We report on recent results about entanglement in the context of particle mixing and oscillations. We study in detail single-particle entanglement arising in two-flavor neutrino mixing. The analysis is performed first in the context of Quantum Mechanics, and then for the case of Quantum Field Theory.

  9. On entanglement in neutrino mixing and oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Blasone, Massimo; Dell' Anno, Fabio; De Siena, Silvio; Illuminati, Fabrizio, E-mail: blasone@sa.infn.i [Dipartimento di Matematica e Informatica, Universita degli Studi di Salerno, Via Ponte don Melillo, I-84084 Fisciano (Italy)

    2010-06-01

    We report on recent results about entanglement in the context of particle mixing and oscillations. We study in detail single-particle entanglement arising in two-flavor neutrino mixing. The analysis is performed first in the context of Quantum Mechanics, and then for the case of Quantum Field Theory.

  10. Two particle entanglement and its geometric duals

    International Nuclear Information System (INIS)

    Wasay, Muhammad Abdul; Bashir, Asma

    2017-01-01

    We show that for a system of two entangled particles, there is a dual description to the particle equations in terms of classical theory of conformally stretched spacetime. We also connect these entangled particle equations with Finsler geometry. We show that this duality translates strongly coupled quantum equations in the pilot-wave limit to weakly coupled geometric equations. (orig.)

  11. Entangled spins and ghost-spins

    Directory of Open Access Journals (Sweden)

    Dileep P. Jatkar

    2017-09-01

    Full Text Available We study patterns of quantum entanglement in systems of spins and ghost-spins regarding them as simple quantum mechanical toy models for theories containing negative norm states. We define a single ghost-spin as in [20] as a 2-state spin variable with an indefinite inner product in the state space. We find that whenever the spin sector is disentangled from the ghost-spin sector (both of which could be entangled within themselves, the reduced density matrix obtained by tracing over all the ghost-spins gives rise to positive entanglement entropy for positive norm states, while negative norm states have an entanglement entropy with a negative real part and a constant imaginary part. However when the spins are entangled with the ghost-spins, there are new entanglement patterns in general. For systems where the number of ghost-spins is even, it is possible to find subsectors of the Hilbert space where positive norm states always lead to positive entanglement entropy after tracing over the ghost-spins. With an odd number of ghost-spins however, we find that there always exist positive norm states with negative real part for entanglement entropy after tracing over the ghost-spins.

  12. Entangled Light Emission From a Diode

    International Nuclear Information System (INIS)

    Stevenson, R. M.; Shields, A. J.; Salter, C. L.; Farrer, I.; Nicoll, C. A.; Ritchie, D. A.

    2011-01-01

    Electrically-driven entangled photon generation is demonstrated for the first time using a single semiconductor quantum dot embedded in a light emitting diode structure. The entanglement fidelity is shown to be of sufficient quality for applications such as quantum key distribution.

  13. Continuous variable tripartite entanglement from twin nonlinearities

    International Nuclear Information System (INIS)

    Olsen, M K; Bradley, A S

    2006-01-01

    In this work, we analyse and compare the continuous variable tripartite entanglement available from the use of two concurrent or cascaded χ (2) nonlinearities. We examine both idealized travelling-wave models and more experimentally realistic intracavity models, showing that tripartite entangled outputs are readily producible. These may be a useful resource for applications such as quantum cryptography and teleportation

  14. Quantum entanglement in polarization and space

    NARCIS (Netherlands)

    Lee, Peter Sing Kin

    2006-01-01

    One of the most intriguing concepts of quantum mechanics is quantum entanglement. Two physical systems are said to be entangled with respect to a certain variable, if their individual outcomes of the variable are undetermined before measurement, but strictly correlated. Measurement of the variable

  15. Teleportation of entanglement over 143 km.

    Science.gov (United States)

    Herbst, Thomas; Scheidl, Thomas; Fink, Matthias; Handsteiner, Johannes; Wittmann, Bernhard; Ursin, Rupert; Zeilinger, Anton

    2015-11-17

    As a direct consequence of the no-cloning theorem, the deterministic amplification as in classical communication is impossible for unknown quantum states. This calls for more advanced techniques in a future global quantum network, e.g., for cloud quantum computing. A unique solution is the teleportation of an entangled state, i.e., entanglement swapping, representing the central resource to relay entanglement between distant nodes. Together with entanglement purification and a quantum memory it constitutes a so-called quantum repeater. Since the aforementioned building blocks have been individually demonstrated in laboratory setups only, the applicability of the required technology in real-world scenarios remained to be proven. Here we present a free-space entanglement-swapping experiment between the Canary Islands of La Palma and Tenerife, verifying the presence of quantum entanglement between two previously independent photons separated by 143 km. We obtained an expectation value for the entanglement-witness operator, more than 6 SDs beyond the classical limit. By consecutive generation of the two required photon pairs and space-like separation of the relevant measurement events, we also showed the feasibility of the swapping protocol in a long-distance scenario, where the independence of the nodes is highly demanded. Because our results already allow for efficient implementation of entanglement purification, we anticipate our research to lay the ground for a fully fledged quantum repeater over a realistic high-loss and even turbulent quantum channel.

  16. Quantum entanglement and quantum computational algorithms

    Indian Academy of Sciences (India)

    We demonstrate that the one- and the two-bit Deutsch-Jozsa algorithm does not require entanglement and can be mapped onto a classical optical scheme. It is only for three and more input bits that the DJ algorithm requires the implementation of entangling transformations and in these cases it is impossible to implement ...

  17. Multiparticle entanglement under the influence of decoherence

    NARCIS (Netherlands)

    Gühne, O.; Bodoky, F.; Blaauboer, M.

    2008-01-01

    We present a method to determine the decay of multiparticle quantum correlations as quantified by the geometric measure of entanglement under the influence of decoherence. With this, we compare the robustness of entanglement in Greenberger-Horne-Zeilinger (GHZ), cluster, W, and Dicke states of four

  18. Holographic entanglement entropy in Lovelock gravities

    NARCIS (Netherlands)

    de Boer, J.; Kulaxizi, M.; Parnachev, A.

    2011-01-01

    We study entanglement entropies of simply connected surfaces in field theories dual to Lovelock gravities. We consider Gauss-Bonnet and cubic Lovelock gravities in detail. In the conformal case the logarithmic terms in the entanglement entropy are governed by the conformal anomalies of the CFT; we

  19. Entanglement, holography and causal diamonds

    Science.gov (United States)

    de Boer, Jan; Haehl, Felix M.; Heller, Michal P.; Myers, Robert C.

    2016-08-01

    We argue that the degrees of freedom in a d-dimensional CFT can be reorganized in an insightful way by studying observables on the moduli space of causal diamonds (or equivalently, the space of pairs of timelike separated points). This 2 d-dimensional space naturally captures some of the fundamental nonlocality and causal structure inherent in the entanglement of CFT states. For any primary CFT operator, we construct an observable on this space, which is defined by smearing the associated one-point function over causal diamonds. Known examples of such quantities are the entanglement entropy of vacuum excitations and its higher spin generalizations. We show that in holographic CFTs, these observables are given by suitably defined integrals of dual bulk fields over the corresponding Ryu-Takayanagi minimal surfaces. Furthermore, we explain connections to the operator product expansion and the first law of entanglemententropy from this unifying point of view. We demonstrate that for small perturbations of the vacuum, our observables obey linear two-derivative equations of motion on the space of causal diamonds. In two dimensions, the latter is given by a product of two copies of a two-dimensional de Sitter space. For a class of universal states, we show that the entanglement entropy and its spin-three generalization obey nonlinear equations of motion with local interactions on this moduli space, which can be identified with Liouville and Toda equations, respectively. This suggests the possibility of extending the definition of our new observables beyond the linear level more generally and in such a way that they give rise to new dynamically interacting theories on the moduli space of causal diamonds. Various challenges one has to face in order to implement this idea are discussed.

  20. Entanglement verification with detection efficiency mismatch

    Science.gov (United States)

    Zhang, Yanbao; Lütkenhaus, Norbert

    Entanglement is a necessary condition for secure quantum key distribution (QKD). When there is an efficiency mismatch between various detectors used in the QKD system, it is still an open problem how to verify entanglement. Here we present a method to address this problem, given that the detection efficiency mismatch is characterized and known. The method works without assuming an upper bound on the number of photons going to each threshold detector. Our results suggest that the efficiency mismatch affects the ability to verify entanglement: the larger the efficiency mismatch is, the smaller the set of entangled states that can be verified becomes. When there is no mismatch, our method can verify entanglement even if the method based on squashing maps [PRL 101, 093601 (2008)] fails.

  1. Optimized entanglement witnesses for Dicke states

    Energy Technology Data Exchange (ETDEWEB)

    Bergmann, Marcel; Guehne, Otfried [Naturwissenschaftlich-Technische Fakultaet, Universitaet Siegen, Department Physik, Walter-Flex-Strasse 3, D-57068 Siegen (Germany)

    2013-07-01

    Quantum entanglement is an important resource for applications in quantum information processing like quantum teleportation and cryptography. Moreover, the number of particles that can be entangled experimentally using polarized photons or ion traps has been significantly enlarged. Therefore, criteria to decide the question whether a given multi-particle state is entangled or not have to be improved. Our approach to this problem uses the notion of PPT mixtures which form an approximation to the set of bi-separable states. With this method, entanglement witnesses can be obtained in a natural manner via linear semi-definite programming. In our contribution, we will present analytical results for entanglement witnesses for Dicke states. This allows to overcome the limitations of convex optimization.

  2. Entanglement, Bell inequality and all that

    Energy Technology Data Exchange (ETDEWEB)

    Narnhofer, Heide; Thirring, Walter [Fakultaet fuer Physik, Universitaet Wien, Boltzmanngasse 5, A-1090 Wien (Austria)

    2012-09-15

    We start from the geometrical observation that a finite set of pure states correspond to some points on a sphere and their convex span cannot be the whole set of states. If we call the left over entangled we can pursue this picture from the simplest case of a two dimensional Hilbert space to the usual Alice-and-Bob game of entangled states and then move to bigger systems and finely to quantum field theory where almost everything is entangled. On the way we encounter more or less known old friends up from the shell structure of states to the monogamy of squashed entanglement. We study how entanglement can be concentrated on a small slice and how it depends on the particular factorization of the Hilbert space.

  3. Entanglement, Bell inequality and all that

    International Nuclear Information System (INIS)

    Narnhofer, Heide; Thirring, Walter

    2012-01-01

    We start from the geometrical observation that a finite set of pure states correspond to some points on a sphere and their convex span cannot be the whole set of states. If we call the left over entangled we can pursue this picture from the simplest case of a two dimensional Hilbert space to the usual Alice-and-Bob game of entangled states and then move to bigger systems and finely to quantum field theory where almost everything is entangled. On the way we encounter more or less known old friends up from the shell structure of states to the monogamy of squashed entanglement. We study how entanglement can be concentrated on a small slice and how it depends on the particular factorization of the Hilbert space.

  4. Entanglement-Gradient Routing for Quantum Networks.

    Science.gov (United States)

    Gyongyosi, Laszlo; Imre, Sandor

    2017-10-27

    We define the entanglement-gradient routing scheme for quantum repeater networks. The routing framework fuses the fundamentals of swarm intelligence and quantum Shannon theory. Swarm intelligence provides nature-inspired solutions for problem solving. Motivated by models of social insect behavior, the routing is performed using parallel threads to determine the shortest path via the entanglement gradient coefficient, which describes the feasibility of the entangled links and paths of the network. The routing metrics are derived from the characteristics of entanglement transmission and relevant measures of entanglement distribution in quantum networks. The method allows a moderate complexity decentralized routing in quantum repeater networks. The results can be applied in experimental quantum networking, future quantum Internet, and long-distance quantum communications.

  5. Maximal Entanglement in High Energy Physics

    Directory of Open Access Journals (Sweden)

    Alba Cervera-Lierta, José I. Latorre, Juan Rojo, Luca Rottoli

    2017-11-01

    Full Text Available We analyze how maximal entanglement is generated at the fundamental level in QED by studying correlations between helicity states in tree-level scattering processes at high energy. We demonstrate that two mechanisms for the generation of maximal entanglement are at work: i $s$-channel processes where the virtual photon carries equal overlaps of the helicities of the final state particles, and ii the indistinguishable superposition between $t$- and $u$-channels. We then study whether requiring maximal entanglement constrains the coupling structure of QED and the weak interactions. In the case of photon-electron interactions unconstrained by gauge symmetry, we show how this requirement allows reproducing QED. For $Z$-mediated weak scattering, the maximal entanglement principle leads to non-trivial predictions for the value of the weak mixing angle $\\theta_W$. Our results are a first step towards understanding the connections between maximal entanglement and the fundamental symmetries of high-energy physics.

  6. Multipartite entanglement detection with nonsymmetric probing

    DEFF Research Database (Denmark)

    Dellantonio, Luca; Das, Sumanta; Appel, Jürgen

    2017-01-01

    We show that spin-squeezing criteria commonly used for entanglement detection can be erroneous if the probe is not symmetric. We then derive a lower bound on squeezing for separable states in spin systems probed asymmetrically. Using this we further develop a procedure that allows us to verify th...... the degree of entanglement of a quantum state in the spin system. Finally, we apply our method for entanglement verification to existing experimental data, and use it to prove the existence of tripartite entanglement in a spin-squeezed atomic ensemble.......We show that spin-squeezing criteria commonly used for entanglement detection can be erroneous if the probe is not symmetric. We then derive a lower bound on squeezing for separable states in spin systems probed asymmetrically. Using this we further develop a procedure that allows us to verify...

  7. Entanglement temperature with Gauss–Bonnet term

    Directory of Open Access Journals (Sweden)

    Shesansu Sekhar Pal

    2015-09-01

    Full Text Available We compute the entanglement temperature using the first law-like of thermodynamics, ΔE=TentΔSEE, up to Gauss–Bonnet term in the Jacobson–Myers entropy functional in any arbitrary spacetime dimension. The computation is done when the entangling region is the geometry of a slab. We also show that such a Gauss–Bonnet term, which becomes a total derivative, when the co-dimension two hypersurface is four dimensional, does not contribute to the finite term in the entanglement entropy. We observe that the Weyl-squared term does not contribute to the entanglement entropy. It is important to note that the calculations are performed when the entangling region is very small and the energy is calculated using the normal Hamiltonian.

  8. Entanglement entropy in top-down models

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Peter A.R.; Taylor, Marika [Mathematical Sciences and STAG Research Centre, University of Southampton,Highfield, Southampton, SO17 1BJ (United Kingdom)

    2016-08-26

    We explore holographic entanglement entropy in ten-dimensional supergravity solutions. It has been proposed that entanglement entropy can be computed in such top-down models using minimal surfaces which asymptotically wrap the compact part of the geometry. We show explicitly in a wide range of examples that the holographic entanglement entropy thus computed agrees with the entanglement entropy computed using the Ryu-Takayanagi formula from the lower-dimensional Einstein metric obtained from reduction over the compact space. Our examples include not only consistent truncations but also cases in which no consistent truncation exists and Kaluza-Klein holography is used to identify the lower-dimensional Einstein metric. We then give a general proof, based on the Lewkowycz-Maldacena approach, of the top-down entanglement entropy formula.

  9. Entanglement entropy in top-down models

    International Nuclear Information System (INIS)

    Jones, Peter A.R.; Taylor, Marika

    2016-01-01

    We explore holographic entanglement entropy in ten-dimensional supergravity solutions. It has been proposed that entanglement entropy can be computed in such top-down models using minimal surfaces which asymptotically wrap the compact part of the geometry. We show explicitly in a wide range of examples that the holographic entanglement entropy thus computed agrees with the entanglement entropy computed using the Ryu-Takayanagi formula from the lower-dimensional Einstein metric obtained from reduction over the compact space. Our examples include not only consistent truncations but also cases in which no consistent truncation exists and Kaluza-Klein holography is used to identify the lower-dimensional Einstein metric. We then give a general proof, based on the Lewkowycz-Maldacena approach, of the top-down entanglement entropy formula.

  10. Superadditivity of distillable entanglement from quantum teleportation

    Science.gov (United States)

    Bandyopadhyay, Somshubhro; Roychowdhury, Vwani

    2005-12-01

    We show that the phenomenon of superadditivity of distillable entanglement observed in multipartite quantum systems results from the consideration of states created during the execution of the standard end-to-end quantum teleportation protocol [and a few additional local operations and classical communication (LOCC) steps] on a linear chain of singlets. Some of these intermediate states are tensor products of bound entangled (BE) states, and hence, by construction possess distillable entanglement, which can be unlocked by simply completing the rest of the LOCC operations required by the underlying teleportation protocol. We use this systematic approach to construct both new and known examples of superactivation of bound entanglement, and examples of activation of BE states using other BE states. A surprising outcome is the construction of noiseless quantum relay channels with no distillable entanglement between any two parties, except for that between the two end nodes.

  11. Superadditivity of distillable entanglement from quantum teleportation

    International Nuclear Information System (INIS)

    Bandyopadhyay, Somshubhro; Roychowdhury, Vwani

    2005-01-01

    We show that the phenomenon of superadditivity of distillable entanglement observed in multipartite quantum systems results from the consideration of states created during the execution of the standard end-to-end quantum teleportation protocol [and a few additional local operations and classical communication (LOCC) steps] on a linear chain of singlets. Some of these intermediate states are tensor products of bound entangled (BE) states, and hence, by construction possess distillable entanglement, which can be unlocked by simply completing the rest of the LOCC operations required by the underlying teleportation protocol. We use this systematic approach to construct both new and known examples of superactivation of bound entanglement, and examples of activation of BE states using other BE states. A surprising outcome is the construction of noiseless quantum relay channels with no distillable entanglement between any two parties, except for that between the two end nodes

  12. Deterministic dense coding with partially entangled states

    Science.gov (United States)

    Mozes, Shay; Oppenheim, Jonathan; Reznik, Benni

    2005-01-01

    The utilization of a d -level partially entangled state, shared by two parties wishing to communicate classical information without errors over a noiseless quantum channel, is discussed. We analytically construct deterministic dense coding schemes for certain classes of nonmaximally entangled states, and numerically obtain schemes in the general case. We study the dependency of the maximal alphabet size of such schemes on the partially entangled state shared by the two parties. Surprisingly, for d>2 it is possible to have deterministic dense coding with less than one ebit. In this case the number of alphabet letters that can be communicated by a single particle is between d and 2d . In general, we numerically find that the maximal alphabet size is any integer in the range [d,d2] with the possible exception of d2-1 . We also find that states with less entanglement can have a greater deterministic communication capacity than other more entangled states.

  13. Quantum entanglement of high angular momenta.

    Science.gov (United States)

    Fickler, Robert; Lapkiewicz, Radek; Plick, William N; Krenn, Mario; Schaeff, Christoph; Ramelow, Sven; Zeilinger, Anton

    2012-11-02

    Single photons with helical phase structures may carry a quantized amount of orbital angular momentum (OAM), and their entanglement is important for quantum information science and fundamental tests of quantum theory. Because there is no theoretical upper limit on how many quanta of OAM a single photon can carry, it is possible to create entanglement between two particles with an arbitrarily high difference in quantum number. By transferring polarization entanglement to OAM with an interferometric scheme, we generate and verify entanglement between two photons differing by 600 in quantum number. The only restrictive factors toward higher numbers are current technical limitations. We also experimentally demonstrate that the entanglement of very high OAM can improve the sensitivity of angular resolution in remote sensing.

  14. Real-time imaging of quantum entanglement.

    Science.gov (United States)

    Fickler, Robert; Krenn, Mario; Lapkiewicz, Radek; Ramelow, Sven; Zeilinger, Anton

    2013-01-01

    Quantum Entanglement is widely regarded as one of the most prominent features of quantum mechanics and quantum information science. Although, photonic entanglement is routinely studied in many experiments nowadays, its signature has been out of the grasp for real-time imaging. Here we show that modern technology, namely triggered intensified charge coupled device (ICCD) cameras are fast and sensitive enough to image in real-time the effect of the measurement of one photon on its entangled partner. To quantitatively verify the non-classicality of the measurements we determine the detected photon number and error margin from the registered intensity image within a certain region. Additionally, the use of the ICCD camera allows us to demonstrate the high flexibility of the setup in creating any desired spatial-mode entanglement, which suggests as well that visual imaging in quantum optics not only provides a better intuitive understanding of entanglement but will improve applications of quantum science.

  15. Entanglement fidelity of quantum memories

    International Nuclear Information System (INIS)

    Surmacz, K.; Nunn, J.; Waldermann, F. C.; Wang, Z.; Walmsley, I. A.; Jaksch, D.

    2006-01-01

    We introduce a figure of merit for a quantum memory which measures the preservation of entanglement between a qubit stored in and retrieved from the memory and an auxiliary qubit. We consider a general quantum memory system consisting of a medium of two level absorbers, with the qubit to be stored encoded in a single photon. We derive an analytic expression for our figure of merit taking into account Gaussian fluctuations in the Hamiltonian parameters, which, for example, model inhomogeneous broadening and storage time dephasing. Finally we specialize to the case of an atomic quantum memory where fluctuations arise predominantly from Doppler broadening and motional dephasing

  16. Entanglement entropy of excited states

    International Nuclear Information System (INIS)

    Alba, Vincenzo; Fagotti, Maurizio; Calabrese, Pasquale

    2009-01-01

    We study the entanglement entropy of a block of contiguous spins in excited states of spin chains. We consider the XY model in a transverse field and the XXZ Heisenberg spin chain. For the latter, we developed a numerical application of the algebraic Bethe ansatz. We find two main classes of states with logarithmic and extensive behavior in the dimension of the block, characterized by the properties of excitations of the state. This behavior can be related to the locality properties of the Hamiltonian having a given state as the ground state. We also provide several details of the finite size scaling

  17. Secret sharing via quantum entanglement

    International Nuclear Information System (INIS)

    Hillery, M.; Buzek, V.

    1999-01-01

    Secret sharing is a procedure for splitting a message into several parts so that no single part is sufficient to read the message, but the entire set is. This procedure can be implemented using either GHZ states or two-particle entangled states. In the quantum case the presence of an eavesdropper will introduce errors so that her presence can be detected. We also discuss how quantum information can be split into parts so that the message can be reconstructed from a sufficiently large subset of the parts. (Authors)

  18. Entanglement and inhibited quantum evolution

    Energy Technology Data Exchange (ETDEWEB)

    Toschek, P E; Balzer, Chr; Hannemann, Th; Wunderlich, Ch; Neuhauser, W [Universitaet Hamburg, Institut fuer Laser-Physik, Jungiusstrasse 9, D-20355 Hamburg (Germany)

    2003-03-14

    The evolution of a quantum system is impeded by the system's state being observed. A test on an ensemble neither proves the causal nexus nor discloses the nature of the inhibition. Two recent experiments that make use of sequential optical or microwave-optical double resonance on an individual trapped ion disprove a dynamical effect of back action by meter or environment. They rather indicate the ionic states involved in the evolution being entangled with the potentially recorded bivalued scattered-light signal.

  19. Die Institution der Sonnenjungfrauen bei den Inkas : ihre Rolle in der Religion und der Gesellschaft / Tarmo Kulmar

    Index Scriptorium Estoniae

    Kulmar, Tarmo, 1950-

    2003-01-01

    Ettekanne sümpoosionilt: Gemeinsames Symposium der Evangelisch-Theologischen Fakultät der Universität Tartu, der Estnischen Studiengesellschaft für Morgenlandkunde und der Deutschen Religionsgeschichtlichen Studiengesellschaft. Tartu, 2001

  20. Sprache der Verwaltung, Sprache der Politik

    DEFF Research Database (Denmark)

    Olden-Jørgensen, Sebastian

    2007-01-01

    Det ældste danske forvaltningssprog er latin, der i sendmiddelalderen får følge først af middelnedertysk og siden af dansk. Hertugdømmerne forvaltes fra centralt hold på nedertysk indtil ca. 1550, derefter på højtysk. I slutningen af 1500-tallet begynder også den lokale administration og kirkespr...

  1. Quantum Entanglement Growth under Random Unitary Dynamics

    Science.gov (United States)

    Nahum, Adam; Ruhman, Jonathan; Vijay, Sagar; Haah, Jeongwan

    2017-07-01

    Characterizing how entanglement grows with time in a many-body system, for example, after a quantum quench, is a key problem in nonequilibrium quantum physics. We study this problem for the case of random unitary dynamics, representing either Hamiltonian evolution with time-dependent noise or evolution by a random quantum circuit. Our results reveal a universal structure behind noisy entanglement growth, and also provide simple new heuristics for the "entanglement tsunami" in Hamiltonian systems without noise. In 1D, we show that noise causes the entanglement entropy across a cut to grow according to the celebrated Kardar-Parisi-Zhang (KPZ) equation. The mean entanglement grows linearly in time, while fluctuations grow like (time )1/3 and are spatially correlated over a distance ∝(time )2/3. We derive KPZ universal behavior in three complementary ways, by mapping random entanglement growth to (i) a stochastic model of a growing surface, (ii) a "minimal cut" picture, reminiscent of the Ryu-Takayanagi formula in holography, and (iii) a hydrodynamic problem involving the dynamical spreading of operators. We demonstrate KPZ universality in 1D numerically using simulations of random unitary circuits. Importantly, the leading-order time dependence of the entropy is deterministic even in the presence of noise, allowing us to propose a simple coarse grained minimal cut picture for the entanglement growth of generic Hamiltonians, even without noise, in arbitrary dimensionality. We clarify the meaning of the "velocity" of entanglement growth in the 1D entanglement tsunami. We show that in higher dimensions, noisy entanglement evolution maps to the well-studied problem of pinning of a membrane or domain wall by disorder.

  2. Entanglement quantification by local unitary operations

    Energy Technology Data Exchange (ETDEWEB)

    Monras, A.; Giampaolo, S. M.; Gualdi, G.; Illuminati, F. [Dipartimento di Matematica e Informatica, Universita degli Studi di Salerno, CNISM, Unita di Salerno, and INFN, Sezione di Napoli-Gruppo Collegato di Salerno, Via Ponte don Melillo, I-84084 Fisciano (Italy); Adesso, G.; Davies, G. B. [School of Mathematical Sciences, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom)

    2011-07-15

    Invariance under local unitary operations is a fundamental property that must be obeyed by every proper measure of quantum entanglement. However, this is not the only aspect of entanglement theory where local unitary operations play a relevant role. In the present work we show that the application of suitable local unitary operations defines a family of bipartite entanglement monotones, collectively referred to as ''mirror entanglement.'' They are constructed by first considering the (squared) Hilbert-Schmidt distance of the state from the set of states obtained by applying to it a given local unitary operator. To the action of each different local unitary operator there corresponds a different distance. We then minimize these distances over the sets of local unitary operations with different spectra, obtaining an entire family of different entanglement monotones. We show that these mirror-entanglement monotones are organized in a hierarchical structure, and we establish the conditions that need to be imposed on the spectrum of a local unitary operator for the associated mirror entanglement to be faithful, i.e., to vanish in and only in separable pure states. We analyze in detail the properties of one particularly relevant member of the family, the ''stellar mirror entanglement'' associated with the traceless local unitary operations with nondegenerate spectra and equispaced eigenvalues in the complex plane. This particular measure generalizes the original analysis of S. M. Giampaolo and F. Illuminati [Phys. Rev. A 76, 042301 (2007)], valid for qubits and qutrits. We prove that the stellar entanglement is a faithful bipartite entanglement monotone in any dimension and that it is bounded from below by a function proportional to the linear entropy and from above by the linear entropy itself, coinciding with it in two- and three-dimensional spaces.

  3. Quantum key distribution with entangled photon sources

    International Nuclear Information System (INIS)

    Ma Xiongfeng; Fung, Chi-Hang Fred; Lo, H.-K.

    2007-01-01

    A parametric down-conversion (PDC) source can be used as either a triggered single-photon source or an entangled-photon source in quantum key distribution (QKD). The triggering PDC QKD has already been studied in the literature. On the other hand, a model and a post-processing protocol for the entanglement PDC QKD are still missing. We fill in this important gap by proposing such a model and a post-processing protocol for the entanglement PDC QKD. Although the PDC model is proposed to study the entanglement-based QKD, we emphasize that our generic model may also be useful for other non-QKD experiments involving a PDC source. Since an entangled PDC source is a basis-independent source, we apply Koashi and Preskill's security analysis to the entanglement PDC QKD. We also investigate the entanglement PDC QKD with two-way classical communications. We find that the recurrence scheme increases the key rate and the Gottesman-Lo protocol helps tolerate higher channel losses. By simulating a recent 144-km open-air PDC experiment, we compare three implementations: entanglement PDC QKD, triggering PDC QKD, and coherent-state QKD. The simulation result suggests that the entanglement PDC QKD can tolerate higher channel losses than the coherent-state QKD. The coherent-state QKD with decoy states is able to achieve highest key rate in the low- and medium-loss regions. By applying the Gottesman-Lo two-way post-processing protocol, the entanglement PDC QKD can tolerate up to 70 dB combined channel losses (35 dB for each channel) provided that the PDC source is placed in between Alice and Bob. After considering statistical fluctuations, the PDC setup can tolerate up to 53 dB channel losses

  4. Quantum Entanglement Growth under Random Unitary Dynamics

    Directory of Open Access Journals (Sweden)

    Adam Nahum

    2017-07-01

    Full Text Available Characterizing how entanglement grows with time in a many-body system, for example, after a quantum quench, is a key problem in nonequilibrium quantum physics. We study this problem for the case of random unitary dynamics, representing either Hamiltonian evolution with time-dependent noise or evolution by a random quantum circuit. Our results reveal a universal structure behind noisy entanglement growth, and also provide simple new heuristics for the “entanglement tsunami” in Hamiltonian systems without noise. In 1D, we show that noise causes the entanglement entropy across a cut to grow according to the celebrated Kardar-Parisi-Zhang (KPZ equation. The mean entanglement grows linearly in time, while fluctuations grow like (time^{1/3} and are spatially correlated over a distance ∝(time^{2/3}. We derive KPZ universal behavior in three complementary ways, by mapping random entanglement growth to (i a stochastic model of a growing surface, (ii a “minimal cut” picture, reminiscent of the Ryu-Takayanagi formula in holography, and (iii a hydrodynamic problem involving the dynamical spreading of operators. We demonstrate KPZ universality in 1D numerically using simulations of random unitary circuits. Importantly, the leading-order time dependence of the entropy is deterministic even in the presence of noise, allowing us to propose a simple coarse grained minimal cut picture for the entanglement growth of generic Hamiltonians, even without noise, in arbitrary dimensionality. We clarify the meaning of the “velocity” of entanglement growth in the 1D entanglement tsunami. We show that in higher dimensions, noisy entanglement evolution maps to the well-studied problem of pinning of a membrane or domain wall by disorder.

  5. Entanglement quantification by local unitary operations

    International Nuclear Information System (INIS)

    Monras, A.; Giampaolo, S. M.; Gualdi, G.; Illuminati, F.; Adesso, G.; Davies, G. B.

    2011-01-01

    Invariance under local unitary operations is a fundamental property that must be obeyed by every proper measure of quantum entanglement. However, this is not the only aspect of entanglement theory where local unitary operations play a relevant role. In the present work we show that the application of suitable local unitary operations defines a family of bipartite entanglement monotones, collectively referred to as ''mirror entanglement.'' They are constructed by first considering the (squared) Hilbert-Schmidt distance of the state from the set of states obtained by applying to it a given local unitary operator. To the action of each different local unitary operator there corresponds a different distance. We then minimize these distances over the sets of local unitary operations with different spectra, obtaining an entire family of different entanglement monotones. We show that these mirror-entanglement monotones are organized in a hierarchical structure, and we establish the conditions that need to be imposed on the spectrum of a local unitary operator for the associated mirror entanglement to be faithful, i.e., to vanish in and only in separable pure states. We analyze in detail the properties of one particularly relevant member of the family, the ''stellar mirror entanglement'' associated with the traceless local unitary operations with nondegenerate spectra and equispaced eigenvalues in the complex plane. This particular measure generalizes the original analysis of S. M. Giampaolo and F. Illuminati [Phys. Rev. A 76, 042301 (2007)], valid for qubits and qutrits. We prove that the stellar entanglement is a faithful bipartite entanglement monotone in any dimension and that it is bounded from below by a function proportional to the linear entropy and from above by the linear entropy itself, coinciding with it in two- and three-dimensional spaces.

  6. Gain maximization in a probabilistic entanglement protocol

    Science.gov (United States)

    di Lorenzo, Antonio; Esteves de Queiroz, Johnny Hebert

    Entanglement is a resource. We can therefore define gain as a monotonic function of entanglement G (E) . If a pair with entanglement E is produced with probability P, the net gain is N = PG (E) - (1 - P) C , where C is the cost of a failed attempt. We study a protocol where a pair of quantum systems is produced in a maximally entangled state ρm with probability Pm, while it is produced in a partially entangled state ρp with the complementary probability 1 -Pm . We mix a fraction w of the partially entangled pairs with the maximally entangled ones, i.e. we take the state to be ρ = (ρm + wUlocρpUloc+) / (1 + w) , where Uloc is an appropriate unitary local operation designed to maximize the entanglement of ρ. This procedure on one hand reduces the entanglement E, and hence the gain, but on the other hand it increases the probability of success to P =Pm + w (1 -Pm) , therefore the net gain N may increase. There may be hence, a priori, an optimal value for w, the fraction of failed attempts that we mix in. We show that, in the hypothesis of a linear gain G (E) = E , even assuming a vanishing cost C -> 0 , the net gain N is increasing with w, therefore the best strategy is to always mix the partially entangled states. Work supported by CNPq, Conselho Nacional de Desenvolvimento Científico e Tecnológico, proc. 311288/2014-6, and by FAPEMIG, Fundação de Amparo à Pesquisa de Minas Gerais, proc. IC-FAPEMIG2016-0269 and PPM-00607-16.

  7. Entanglement fidelity of the standard quantum teleportation channel

    Energy Technology Data Exchange (ETDEWEB)

    Li, Gang; Ye, Ming-Yong, E-mail: myye@fjnu.edu.cn; Lin, Xiu-Min

    2013-09-16

    We consider the standard quantum teleportation protocol where a general bipartite state is used as entanglement resource. We use the entanglement fidelity to describe how well the standard quantum teleportation channel transmits quantum entanglement and give a simple expression for the entanglement fidelity when it is averaged on all input states.

  8. Probabilistic Teleportation of a Four-Particle Entangled State

    Institute of Scientific and Technical Information of China (English)

    ZHAN You-Bang; FU Hao; DONG Zheng-Chao

    2005-01-01

    A Scheme for teleporting an unknown four-particle entangled state is proposed via entangled swapping. In this scheme, four pairs of entangled particles are used as quantum channel. It is shown that, if the four pairs of particles are nonmaximally entangled, the teleportation can be successfully realized with certain probability if a receiver adopts some appropriate unitary transformations.

  9. Willkommen in Panorama Theresienstadt. Kinematographie und Zerstörung in der Stadt namens „Als Ob“ (Lesung H. G. Adlers

    Directory of Open Access Journals (Sweden)

    Irina Sandomirskaja

    2016-10-01

    Full Text Available In seinem Theresienstadt 1941-1945 beschreibt Hans Günther Adler Episoden aus dem Prozess des Filmens in Theresienstadt. Seine größte Aufmerksamkeit liegt dabei auf der Produktion des Films von 1944, den er zusammenfassend aufgrund seines Zwecks und seiner Durchführung „der grausige Filmkarneval” nennt. Bemerkenswerterweise widmet Adler ein ganzes Buchkapitel der Beschreibung des kulturellen Lebens von Theresienstadt, ohne dabei den Film in zusammen mit anderen Beispielen kultureller Ausdrucksformen zu nennen – die Beschreibung des Films ist in der administrativen Chronik von Theresienstadt eingegliedert. Der Film erhält einen Platz für sich innerhalb des Kontextes der bürokratischen Umgestaltung Theresienstadts von einem geschlossenen Lager zu einem „Ghetto“ und schließlich zu einer rein dekorativen „jüdischen Siedlung“ hin. Diese letztere Umgestaltung beschreibt Adler als Teil einer zynischen Kampagne zur „Verschönerung“ von Theresienstadt, im Zuge derer SS und Verwaltung versuchten, das Lager für internationale Beobachter vorzeigbar zu machen. Adler beschreibt den „grausigen Filmkarneval“ als Aushängeschild der Kampagne und schließt ihn so entschieden aus dem Bereich kultureller Phänomene aus, als würde er jede Möglichkeit zu seiner Entlastung ablehnen. Stattdessen schreibt er das Projekt in die administrative Logik der Vernichtung ein, wodurch das Filmen zu einer zusätzlichen – in ihrer Grausamkeit ideenreichen und effektiven – Technik moralischer Vernichtung in der Welt des „verwalteten Menschen” avanciert. In diesem Artikel werde ich Adlers Sicht auf das Bewegtbild als überwiegend administratives Mittel, nicht als Medium kulturellen Ausdrucks hervorheben. Diese Ansicht wird durchaus herausfordernd und komplex, wenn Adlers Zeugenbericht über das Filmprojekt in Theresienstadt in Zusammenhang mit seinen Überlegungen zu mechanisch reproduzierbaren und vor allem bewegten Bildern in Adlers

  10. Primary extraparenchymal hemorrhage of the posterior cranal fossa as a premonitory symptom of atlanto-axial instability; Traumatische extraparenchymale Blutung der hinteren Schaedelgrube als Warnsymptom einer atlantoaxialen Instabilitaet

    Energy Technology Data Exchange (ETDEWEB)

    Holl, K.; Rolli, K.; Olschowski, A.; Wurm, G. [Neurochirurgische Abt., Landesnervenklinik Linz (Austria); Nussbaumer, K. [Neuroradiologische Abt., Landesnervenklinik Linz (Austria)

    2001-07-01

    The contribution discusses the cases of five patients with cranio-cerebral trauma, (four children and one adult patient), where CT examination revealed extraparenchymal hemorrhage of the posterior cranal fossa, which did not fit into their pattern of intracranial trauma and therefore gave reason to suspect a lesion of the upper cervical spine. The various types of hemorrhage found are explained, as well as the underlying cervical spine lesions, and the choice of respective therapies which proved to be successful. (orig./CB) [German] Wir berichten ueber fuenf Patienten nach Schaedel-Hirn-Trauma, deren gemeinsamer Befund in der kraniellen Computertomographie eine extraparenchymale Blutung der hinteren Schaedelgrube (HSG) ohne Zusammenhang mit dem uebrigen intrakraniellen Verletzungsmuster bzw. ohne sonstige intrakranielle Verletzung war. Es handelte sich um vier Kinder und einen Erwachsenen mit einem Durchschnittsalter von 8,8 (4-22) Jahren. Drei dieser Patienten wiesen eine epidurale Blutung am Clivus bzw. am Foramen magnum auf, bei einem Patienten handelte es sich um eine Subarachnoidalblutung um das Cerebellum, bei einem weiteren Patienten lag eine Blutung im IV. Ventrikel vor. Diese infratentoriellen Blutungen waren der erste Hinweis, dass eine Verletzung in der oberen Halswirbelsaeule (HWS) vorliegen koennte. Es wurde bei den vier Kindern als zugrundeliegende Ursache der Blutung eine ligamentaere Verletzung C1/C2 diagnostiziert, nur bei dem erwachsenen Patienten lag eine knoecherne Verletzung C1/C2 vor. Die Therapie erfolgte in den vier Faellen mit Instabilitaet chirurgisch, bei dem Patienten ohne Instabilitaet konservativ. Nach einem mittleren Nachbeobachtungszeitraum von 5,2 Jahren waren alle operierten Patienten klinisch gebessert bzw. weiterhin neurologisch unauffaellig. Es konnte bei allen Patienten eine stabile Situation C1/C2 bei guter Funktionalitaet der HWS nachgewiesen werden. (orig.)

  11. Quantum entanglement of baby universes

    International Nuclear Information System (INIS)

    Aganagic, Mina; Okuda, Takuya; Ooguri, Hirosi

    2007-01-01

    We study quantum entanglements of baby universes which appear in non-perturbative corrections to the OSV formula for the entropy of extremal black holes in type IIA string theory compactified on the local Calabi-Yau manifold defined as a rank 2 vector bundle over an arbitrary genus G Riemann surface. This generalizes the result for G=1 in hep-th/0504221. Non-perturbative terms can be organized into a sum over contributions from baby universes, and the total wave-function is their coherent superposition in the third quantized Hilbert space. We find that half of the universes preserve one set of supercharges while the other half preserve a different set, making the total universe stable but non-BPS. The parent universe generates baby universes by brane/anti-brane pair creation, and baby universes are correlated by conservation of non-normalizable D-brane charges under the process. There are no other source of entanglement of baby universes, and all possible states are superposed with the equal weight

  12. Quantum entanglement of baby universes

    International Nuclear Information System (INIS)

    Essman, Eric P.; Aganagic, Mina; Okuda, Takuya; Ooguri, Hirosi

    2006-01-01

    We study quantum entanglements of baby universes which appear in non-perturbative corrections to the OSV formula for the entropy of extremal black holes in type IIA string theory compactified on the local Calabi-Yau manifold defined as a rank 2 vector bundle over an arbitrary genus G Riemann surface. This generalizes the result for G=1 in hep-th/0504221. Non-perturbative terms can be organized into a sum over contributions from baby universes, and the total wave-function is their coherent superposition in the third quantized Hilbert space. We find that half of the universes preserve one set of supercharges while the other half preserve a different set, making the total universe stable but non-BPS. The parent universe generates baby universes by brane/anti-brane pair creation, and baby universes are correlated by conservation of non-normalizable D-brane charges under the process. There are no other source of entanglement of baby universes, and all possible states are superposed with the equal weight

  13. Linearity of holographic entanglement entropy

    Energy Technology Data Exchange (ETDEWEB)

    Almheiri, Ahmed [Stanford Institute for Theoretical Physics, Department of Physics,Stanford University, Stanford, CA 94305 (United States); Dong, Xi [School of Natural Sciences, Institute for Advanced Study,Princeton, NJ 08540 (United States); Swingle, Brian [Stanford Institute for Theoretical Physics, Department of Physics,Stanford University, Stanford, CA 94305 (United States)

    2017-02-14

    We consider the question of whether the leading contribution to the entanglement entropy in holographic CFTs is truly given by the expectation value of a linear operator as is suggested by the Ryu-Takayanagi formula. We investigate this property by computing the entanglement entropy, via the replica trick, in states dual to superpositions of macroscopically distinct geometries and find it consistent with evaluating the expectation value of the area operator within such states. However, we find that this fails once the number of semi-classical states in the superposition grows exponentially in the central charge of the CFT. Moreover, in certain such scenarios we find that the choice of surface on which to evaluate the area operator depends on the density matrix of the entire CFT. This nonlinearity is enforced in the bulk via the homology prescription of Ryu-Takayanagi. We thus conclude that the homology constraint is not a linear property in the CFT. We also discuss the existence of ‘entropy operators’ in general systems with a large number of degrees of freedom.

  14. Der Vertragsarzt als Schlüsselfigur der Leistungsversorgung

    OpenAIRE

    Gassner, Ulrich M. (Prof.)

    2010-01-01

    Der Vertragsarzt als Schlüsselfigur der Leistungsversorgung. - In: Tıpta işbirliği ve hukuksal sorunlar = Delegation und Kooperation im Gesundheitswesen / ed.: Hakan Hakeri ... - Samsun : Adalet, 2010. - S. 209-222

  15. Quantum Entanglement: Separability, Measure, Fidelity of Teleportation, and Distillation

    Directory of Open Access Journals (Sweden)

    Ming Li

    2010-01-01

    Full Text Available Quantum entanglement plays crucial roles in quantum information processing. Quantum entangled states have become the key ingredient in the rapidly expanding field of quantum information science. Although the nonclassical nature of entanglement has been recognized for many years, considerable efforts have been taken to understand and characterize its properties recently. In this review, we introduce some recent results in the theory of quantum entanglement. In particular separability criteria based on the Bloch representation, covariance matrix, normal form and entanglement witness, lower bounds, subadditivity property of concurrence and tangle, fully entangled fraction related to the optimal fidelity of quantum teleportation, and entanglement distillation will be discussed in detail.

  16. Cloning the entanglement of a pair of quantum bits

    International Nuclear Information System (INIS)

    Lamoureux, Louis-Philippe; Navez, Patrick; Cerf, Nicolas J.; Fiurasek, Jaromir

    2004-01-01

    It is shown that any quantum operation that perfectly clones the entanglement of all maximally entangled qubit pairs cannot preserve separability. This 'entanglement no-cloning' principle naturally suggests that some approximate cloning of entanglement is nevertheless allowed by quantum mechanics. We investigate a separability-preserving optimal cloning machine that duplicates all maximally entangled states of two qubits, resulting in 0.285 bits of entanglement per clone, while a local cloning machine only yields 0.060 bits of entanglement per clone

  17. Residual entanglement and sudden death: A direct connection

    International Nuclear Information System (INIS)

    Oliveira, J.G.G. de; Peixoto de Faria, J.G.; Nemes, M.C.

    2011-01-01

    We explore the results of [V. Coffman, et al., Phys. Rev. A 61 (2000) 052306] derived for general tripartite states in a dynamical context. We study a class of physically motivated tripartite systems. We show that whenever entanglement sudden death occurs in one of the partitions residual entanglement will appear. For fourpartite systems however, the appearance of residual entanglement is not conditioned by sudden death of entanglement. We can only say that if sudden death of entanglement occurs in some partition there will certainly be residual entanglement. -- Highlights: ► For tripartite systems we show there exists residual entanglement if sudden death occurs. ► For fourpartite systems, the residual entanglement is not conditioned by sudden death. ► If sudden death of entanglement occurs there will certainly be residual entanglement.

  18. Geschwisterbeziehungen in der Verarbeitung sexueller Traumatisierung: Der Film "Das Fest"

    OpenAIRE

    Sohni, Hans

    2001-01-01

    Filme reizen als Gegenstand psychoanalytischer Kunstinterpretation durch ihre strukturelle Nähe zum "szenischen Verstehen" und bereichern unsere Einsicht in menschliche Beziehungen. Der Film "Das Fest" lohnt wegen seiner besonderen ästhetischen Form und wegen seiner Aussage zur Geschwisterbeziehung. Nach filmjournalistischer Einschätzung zeigt er die Demontage der bürgerlichen Gesellschaft und die Reinszenierung destruktiver Gewalt. In der Interpretation dieses Beitrags führt der Film dagegen...

  19. Gauge field entanglement in Kitaev's honeycomb model

    Science.gov (United States)

    Dóra, Balázs; Moessner, Roderich

    2018-01-01

    A spin fractionalizes into matter and gauge fermions in Kitaev's spin liquid on the honeycomb lattice. This follows from a Jordan-Wigner mapping to fermions, allowing for the construction of a minimal entropy ground-state wave function on the cylinder. We use this to calculate the entanglement entropy by choosing several distinct partitionings. First, by partitioning an infinite cylinder into two, the -ln2 topological entanglement entropy is reconfirmed. Second, the reduced density matrix of the gauge sector on the full cylinder is obtained after tracing out the matter degrees of freedom. This allows for evaluating the gauge entanglement Hamiltonian, which contains infinitely long-range correlations along the symmetry axis of the cylinder. The matter-gauge entanglement entropy is (Ny-1 )ln2 , with Ny the circumference of the cylinder. Third, the rules for calculating the gauge sector entanglement of any partition are determined. Rather small correctly chosen gauge partitions can still account for the topological entanglement entropy in spite of long-range correlations in the gauge entanglement Hamiltonian.

  20. Cosmological perturbations in the entangled inflationary universe

    Science.gov (United States)

    Robles-Pérez, Salvador J.

    2018-03-01

    In this paper, the model of a multiverse made up of universes that are created in entangled pairs that conserve the total momentum conjugated to the scale factor is presented. For the background spacetime, assumed is a Friedmann-Robertson-Walker metric with a scalar field with mass m minimally coupled to gravity. For the fields that propagate in the entangled spacetimes, the perturbations of the spacetime and the scalar field, whose quantum states become entangled too, are considered. They turn out to be in a quasithermal state, and the corresponding thermodynamical magnitudes are computed. Three observables are expected to be caused by the creation of the universes in entangled pairs: a modification of the Friedmann equation because of the entanglement of the spacetimes, a modification of the effective value of the potential of the scalar field by the backreaction of the perturbation modes, and a modification of the spectrum of fluctuations because the thermal distribution is induced by the entanglement of the partner universes. The later would be a distinctive feature of the creation of universes in entangled pairs.

  1. The geometry of entanglement and Grover's algorithm

    International Nuclear Information System (INIS)

    Iwai, Toshihiro; Hayashi, Naoki; Mizobe, Kimitake

    2008-01-01

    A measure of entanglement with respect to a bipartite partition of n-qubit has been defined and studied from the viewpoint of Riemannian geometry (Iwai 2007 J. Phys. A: Math. Theor. 40 12161). This paper has two aims. One is to study further the geometry of entanglement, and the other is to investigate Grover's search algorithms, both the original and the fixed-point ones, in reference with entanglement. As the distance between the maximally entangled states and the separable states is known already in the previous paper, this paper determines the set of maximally entangled states nearest to a typical separable state which is used as an initial state in Grover's search algorithms, and to find geodesic segments which realize the above-mentioned distance. As for Grover's algorithms, it is already known that while the initial and the target states are separable, the algorithms generate sequences of entangled states. This fact is confirmed also in the entanglement measure proposed in the previous paper, and then a split Grover algorithm is proposed which generates sequences of separable states only with respect to the bipartite partition

  2. Heralded entanglement of two remote atoms

    Science.gov (United States)

    Krug, Michael; Hofmann, Julian; Ortegel, Norbert; Gerard, Lea; Redeker, Kai; Henkel, Florian; Rosenfeld, Wenjamin; Weber, Markus; Weinfurter, Harald

    2012-06-01

    Entanglement between atomic quantum memories at remote locations will be a key resource for future applications in quantum communication. One possibility to generate such entanglement over large distances is entanglement swapping starting from two quantum memories each entangled with a photon. The photons can be transported to a Bell-state measurement where after the atomic quantum memories are projected onto an entangled state. We have set up two independently operated single atom experiments separated by 20 m. Via a spontaneous decay process each quantum memory, in our case a single Rb-87 atom, emits a single photon whose polarization is entangled with the atomic spin. The photons one emitted from each atom are collected into single-mode optical fibers guided to a non-polarizing 50-50 beam-splitter and detected by avalanche photodetectors. Bunching of indistinguishable photons allows to perform a Bell-state measurement on the photons. Conditioned on the registration of particular two-photon coincidences the spin states of both atoms are measured. The observed correlations clearly prove the entanglement of the two atoms. This is a first step towards creating a basic node of a quantum network as well as a key prerequisite for a future loophole-free test of Bell's inequality.

  3. Der Sport und die traditionelle Bewegungskultur der Aborigines

    OpenAIRE

    Wrogemann, Ohle

    2001-01-01

    Bei mehreren Studienaufenthalten in Australien wurde nach den Betrachtungsweisen der deutschen Sportwissenschaft umfangreiches Material der nachstehenden Quellen gesammelt: persönliche Kontakte zu einzelnen Personen, Besuch von öffentlichen und privaten Institutionen, Verfolgen des aktuellen Mediengeschehens, narrative Interviews mit Aborigines, Gespräche mit Experten unterschiedlicher Fachrichtungen, Politikern und Personen der multikulturellen australischen Gesellschaft, Teilnahme ...

  4. Der Heilige Geist und die Realisierung des Glaubens in der ...

    African Journals Online (AJOL)

    29. Juli 2016 ... der Sprache bis hin zu den kulturellen und religiösen. Zeichensystemen, muss von dem Einzelnen empfangen und angeeignet werden. Kommunikation, auch die religiöse, verwirklicht sich ausschließlich in der Spannung von geschichtlicher Abhängigkeit und Transformation der überlieferten Gehalte im ...

  5. Zum Begriff der kommunikativen function in der Linguistik

    Directory of Open Access Journals (Sweden)

    Stojan Bračič

    1987-12-01

    Full Text Available In diesem Artikel soli der Funktionsbegriff in der Linguistik diskutiert  werden, insbesondere der Begr'iff der kotnmunikativen Funktion. Es geht· nur um eine allge­ meine Behandlung  von Charakteristiken des Begriffs kommunikative Funktion. Am Anfang  wird eine Rdhe bekannter und doch recht miterschiedlicher Bedeutungsin­ terpretationert des Funktionsbegriffs in der Linguistik  übersichtlich angeführt. Das zweite Unterkapitel versucht  es, sich mit verschiedenen  Gesichtspunkteri der  nach Wilhelm SCHMIDT definierten  kommunikativen Funktion auseinanderzusetzen: u. a. mii ihrer Verwurzelung  in der funktional  korrimunikativen Sprachbesc4reibung, mit dem  Unterscheiden  von kommunikativen Funktionen auf  verschiedenen  Ebe­ nen (kommunikative Funktion des Textes,  kommunikative Funktion der  Aus­ drucksmittel, kommunikative Funktion der Sprache  bzw. des Sprachsystems, fer­ nei: zieht es eine hypothetisch  annehmbare rezeptive Komponente der kommunikati­ ven Funktion heran  und macht schließlich den Versuch einer Distinktion zwischen direkter  (unmittelbarer ud indirekter  (mittelbarer Ausprägung einzelner koriimu­ nikativer Funktionert. Es wird auch auf die Funktion verwiesen, die der Text für den Rezipienten  hat.  Der Abschluß bringt zusammenfassend die wesentlichen Erkennt­ nisse dieses Beitrags.

  6. Developments in entanglement theory and applications to relevant physical systems

    OpenAIRE

    Lamata Manuel, Lucas

    2007-01-01

    This Thesis is devoted to the analysis of entanglement in relevant physical systems. Entanglement is the conducting theme of this research, though I do not dedicate to a single topic, but consider a wide scope of physical situations. I have followed mainly three lines of research for this Thesis, with a series of different works each, which are, Entanglement and Relativistic Quantum Theory, Continuous-variable entanglement, and Multipartite entanglement.

  7. Entanglement replication in driven dissipative many-body systems.

    Science.gov (United States)

    Zippilli, S; Paternostro, M; Adesso, G; Illuminati, F

    2013-01-25

    We study the dissipative dynamics of two independent arrays of many-body systems, locally driven by a common entangled field. We show that in the steady state the entanglement of the driving field is reproduced in an arbitrarily large series of inter-array entangled pairs over all distances. Local nonclassical driving thus realizes a scale-free entanglement replication and long-distance entanglement distribution mechanism that has immediate bearing on the implementation of quantum communication networks.

  8. Dynamics of pairwise entanglement between two Tavis-Cummings atoms

    International Nuclear Information System (INIS)

    Guo Jinliang; Song Heshan

    2008-01-01

    We investigate the time evolution of pairwise entanglement between two Tavis-Cummings atoms for various entangled initial states, including pure and mixed states. We find that the phenomenon of entanglement sudden death behaviors is distinct in the evolution of entanglement for different initial states. What deserves mentioning here is that the initial portion of the excited state in the initial state is responsible for the sudden death of entanglement, and the degree of this effect also depends on the initial states

  9. Entanglement witnesses arising from exposed positive linear maps

    OpenAIRE

    Ha, Kil-Chan; Kye, Seung-Hyeok

    2011-01-01

    We consider entanglement witnesses arising from positive linear maps which generate exposed extremal rays. We show that every entanglement can be detected by one of these witnesses, and this witness detects a unique set of entanglement among those. Therefore, they provide a minimal set of witnesses to detect all entanglement in a sense. Furthermore, if those maps are indecomposable then they detect large classes of entanglement with positive partial transposes which have nonempty relative int...

  10. Entanglement quantification by local unitary operations

    Science.gov (United States)

    Monras, A.; Adesso, G.; Giampaolo, S. M.; Gualdi, G.; Davies, G. B.; Illuminati, F.

    2011-07-01

    Invariance under local unitary operations is a fundamental property that must be obeyed by every proper measure of quantum entanglement. However, this is not the only aspect of entanglement theory where local unitary operations play a relevant role. In the present work we show that the application of suitable local unitary operations defines a family of bipartite entanglement monotones, collectively referred to as “mirror entanglement.” They are constructed by first considering the (squared) Hilbert-Schmidt distance of the state from the set of states obtained by applying to it a given local unitary operator. To the action of each different local unitary operator there corresponds a different distance. We then minimize these distances over the sets of local unitary operations with different spectra, obtaining an entire family of different entanglement monotones. We show that these mirror-entanglement monotones are organized in a hierarchical structure, and we establish the conditions that need to be imposed on the spectrum of a local unitary operator for the associated mirror entanglement to be faithful, i.e., to vanish in and only in separable pure states. We analyze in detail the properties of one particularly relevant member of the family, the “stellar mirror entanglement” associated with the traceless local unitary operations with nondegenerate spectra and equispaced eigenvalues in the complex plane. This particular measure generalizes the original analysis of S. M. Giampaolo and F. Illuminati [Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.76.042301 76, 042301 (2007)], valid for qubits and qutrits. We prove that the stellar entanglement is a faithful bipartite entanglement monotone in any dimension and that it is bounded from below by a function proportional to the linear entropy and from above by the linear entropy itself, coinciding with it in two- and three-dimensional spaces.

  11. Entanglement purification and concentration of electron-spin entangled states using quantum-dot spins in optical microcavities

    International Nuclear Information System (INIS)

    Wang Chuan; Zhang Yong; Jin Guangsheng

    2011-01-01

    We present an entanglement purification protocol and an entanglement concentration protocol for electron-spin entangled states, resorting to quantum-dot spin and optical-microcavity-coupled systems. The parity-check gates (PCGs) constructed by the cavity-spin-coupling system provide a different method for the entanglement purification of electron-spin entangled states. This protocol can efficiently purify an electron ensemble in a mixed entangled state. The PCGs can also concentrate electron-spin pairs in less-entangled pure states efficiently. The proposed methods are more flexible as only single-photon detection and single-electron detection are needed.

  12. Qualitative Forschung in der Technikpsychologie

    DEFF Research Database (Denmark)

    Schraube, Ernst; Chimirri, Niklas Alexander

    2017-01-01

    Die qualitative Erforschung der Beziehungen zwischen Mensch und Technik wird zunehmend ein Thema in der Psychologie. Das Kapitel beschreibt die Entstehung psychologischer Technikforschung, den Stellenwert qualitativer Forschung in deren Entwicklung, sowie unterschiedliche theoretische und...

  13. Die Last mit der Lust

    Directory of Open Access Journals (Sweden)

    Lutz Sauerteig

    2004-03-01

    Full Text Available Robert Jütte legt mit Lust ohne Last eine umfassende, allgemeinverständliche und spannend zu lesende Geschichte der Empfängnisverhütung von der Antike bis in die unmittelbare Gegenwart vor.

  14. Evolution of entanglement under echo dynamics

    International Nuclear Information System (INIS)

    Prosen, Tomaz; Znidaric, Marko; Seligman, Thomas H.

    2003-01-01

    Echo dynamics and fidelity are often used to discuss stability in quantum-information processing and quantum chaos. Yet fidelity yields no information about entanglement, the characteristic property of quantum mechanics. We study the evolution of entanglement in echo dynamics. We find qualitatively different behavior between integrable and chaotic systems on one hand and between random and coherent initial states for integrable systems on the other. For the latter the evolution of entanglement is given by a classical time scale. Analytic results are illustrated numerically in a Jaynes-Cummings model

  15. Detecting Kondo Entanglement by Electron Conductance

    Science.gov (United States)

    Yoo, Gwangsu; Lee, S.-S. B.; Sim, H.-S.

    2018-04-01

    Quantum entanglement between an impurity spin and electrons nearby is a key property of the single-channel Kondo effects. We show that the entanglement can be detected by measuring electron conductance through a double quantum dot in an orbital Kondo regime. We derive a relation between the entanglement and the conductance, when the SU(2) spin symmetry of the regime is weakly broken. The relation reflects the universal form of many-body states near the Kondo fixed point. Using it, the spatial distribution of the entanglement—hence, the Kondo cloud—can be detected, with breaking of the symmetry spatially nonuniformly by electrical means.

  16. Scattering effect on entanglement propagation in RCFTs

    Energy Technology Data Exchange (ETDEWEB)

    Numasawa, Tokiro [Yukawa Institute for Theoretical Physics, Kyoto University,Kitashirakawa Oiwakecho, Sakyo-ku, Kyoto, 606-8502 (Japan); Kavli Institute for Theoretical Physics, University of California Santa Barbara,Santa Barbara, CA, 93106 (United States)

    2016-12-14

    In this paper we discuss the scattering effect on entanglement propagation in RCFTs. In our setup, we consider the time evolution of excited states created by the insertion of many local operators. Our results show that because of the finiteness of quantum dimension, entanglement is not changed after the scattering in RCFTs. In this mean, entanglement is conserved after the scattering event in RCFTs, which reflects the integrability of the system. Our results are also consistent with the free quasiparticle picture after the global quenches.

  17. Quantum entanglement and fixed-point bifurcations

    International Nuclear Information System (INIS)

    Hines, Andrew P.; McKenzie, Ross H.; Milburn, G.J.

    2005-01-01

    How does the classical phase-space structure for a composite system relate to the entanglement characteristics of the corresponding quantum system? We demonstrate how the entanglement in nonlinear bipartite systems can be associated with a fixed-point bifurcation in the classical dynamics. Using the example of coupled giant spins we show that when a fixed point undergoes a supercritical pitchfork bifurcation, the corresponding quantum state--the ground state--achieves its maximum amount of entanglement near the critical point. We conjecture that this will be a generic feature of systems whose classical limit exhibits such a bifurcation

  18. Task-oriented maximally entangled states

    International Nuclear Information System (INIS)

    Agrawal, Pankaj; Pradhan, B

    2010-01-01

    We introduce the notion of a task-oriented maximally entangled state (TMES). This notion depends on the task for which a quantum state is used as the resource. TMESs are the states that can be used to carry out the task maximally. This concept may be more useful than that of a general maximally entangled state in the case of a multipartite system. We illustrate this idea by giving an operational definition of maximally entangled states on the basis of communication tasks of teleportation and superdense coding. We also give examples and a procedure to obtain such TMESs for n-qubit systems.

  19. Teleportation of Multi-qudit Entangled States

    Institute of Scientific and Technical Information of China (English)

    ZHAN Xiao-Gui; LI Hong-Mei; ZENG Hao-Sheng

    2006-01-01

    @@ We propose a method to realize the teleportation of an unknown entangled state that consists of many qudits through a partially entangled-qudit quantum channel with the help of 2 log2 d-bit classical communication. The operations used in the teleportation process include a generalized Bell-state measurement and a series of singlequdit π-measurements performed by Alice, a series of generalized qudit-Pauli gates and two-level unitary gates,as well as a qubit measurement performed by Bob. For a maximally entangled quantum channel, the successful probability of the teleportation becomes unit.

  20. Experimental Measurement-Device-Independent Entanglement Detection

    Science.gov (United States)

    Nawareg, Mohamed; Muhammad, Sadiq; Amselem, Elias; Bourennane, Mohamed

    2015-02-01

    Entanglement is one of the most puzzling features of quantum theory and of great importance for the new field of quantum information. The determination whether a given state is entangled or not is one of the most challenging open problems of the field. Here we report on the experimental demonstration of measurement-device-independent (MDI) entanglement detection using witness method for general two qubits photon polarization systems. In the MDI settings, there is no requirement to assume perfect implementations or neither to trust the measurement devices. This experimental demonstration can be generalized for the investigation of properties of quantum systems and for the realization of cryptography and communication protocols.

  1. Entanglement detection in hybrid optomechanical systems

    International Nuclear Information System (INIS)

    De Chiara, Gabriele; Paternostro, Mauro; Palma, G. Massimo

    2011-01-01

    We study a device formed by a Bose-Einstein condensate (BEC) coupled to the field of a cavity with a moving end mirror and find a working point such that the mirror-light entanglement is reproduced by the BEC-light quantum correlations. This provides an experimentally viable tool for inferring mirror-light entanglement with only a limited set of assumptions. We prove the existence of tripartite entanglement in the hybrid device, persisting up to temperatures of a few milli-Kelvin, and discuss a scheme to detect it.

  2. Multipartite Entanglement Detection with Minimal Effort

    Science.gov (United States)

    Knips, Lukas; Schwemmer, Christian; Klein, Nico; Wieśniak, Marcin; Weinfurter, Harald

    2016-11-01

    Certifying entanglement of a multipartite state is generally considered a demanding task. Since an N qubit state is parametrized by 4N-1 real numbers, one might naively expect that the measurement effort of generic entanglement detection also scales exponentially with N . Here, we introduce a general scheme to construct efficient witnesses requiring a constant number of measurements independent of the number of qubits for states like, e.g., Greenberger-Horne-Zeilinger states, cluster states, and Dicke states. For four qubits, we apply this novel method to experimental realizations of the aforementioned states and prove genuine four-partite entanglement with two measurement settings only.

  3. Emotionalisierung der Nachhaltigkeitskommunikation

    DEFF Research Database (Denmark)

    Pedersen, Anne Grethe Julius

    Nachhaltigkeitskommunikation (Brugger 2010: 3f). Untersucht wird das Potenzial kommunikativer Handlungen über soziales und ökologisches Engagement, bestimmte Gefühle bei den Empfängern hervorzurufen und eine emotionale Bindung zum Unternehmen herzustellen, u.a. durch emotive Ausdrücke und Bilder, Intensivierungen und...... emotional (mehr als rational) angesprochen - Welche Emotionalisierungsstrategien werden benutzt - Inwieweit unterscheidet sich die deutschsprachige Nachhaltigkeitskommunikation von der dänischsprachigen. Das Textkorpus umfasst online verfügbare Nachhaltigkeitskommunikation auf Websites und in neuen Medien......Die Nachhaltigkeitskommunikation gewinnt an Umfang und Bedeutung und immer öfter werden bei der Bewertung von Unternehmen durch z.B. Investoren und Kunden auch nicht-finanzielle Aspekte herangezogen. Im Fokus des vorliegenden Beitrags steht die emotionale Dimension der unternehmerischen...

  4. Entanglement entropy with a time-dependent Hamiltonian

    Science.gov (United States)

    Sivaramakrishnan, Allic

    2018-03-01

    The time evolution of entanglement tracks how information propagates in interacting quantum systems. We study entanglement entropy in CFT2 with a time-dependent Hamiltonian. We perturb by operators with time-dependent source functions and use the replica trick to calculate higher-order corrections to entanglement entropy. At first order, we compute the correction due to a metric perturbation in AdS3/CFT2 and find agreement on both sides of the duality. Past first order, we find evidence of a universal structure of entanglement propagation to all orders. The central feature is that interactions entangle unentangled excitations. Entanglement propagates according to "entanglement diagrams," proposed structures that are motivated by accessory spacetime diagrams for real-time perturbation theory. To illustrate the mechanisms involved, we compute higher-order corrections to free fermion entanglement entropy. We identify an unentangled operator, one which does not change the entanglement entropy to any order. Then, we introduce an interaction and find it changes entanglement entropy by entangling the unentangled excitations. The entanglement propagates in line with our conjecture. We compute several entanglement diagrams. We provide tools to simplify the computation of loop entanglement diagrams, which probe UV effects in entanglement propagation in CFT and holography.

  5. LEXIKALISCHE MITTEL IN DER HOTELWERBUNG

    OpenAIRE

    Blažević, Nevenka

    2003-01-01

    Werbung ist das wichtigste Marketinginstrument in der Hotellerie. Bei jeder Werbekampagne ist die sprachliche Seite von großer Bedeutung. In diesem Beitrag wird die lexikalische Ebene der Prospekttexte analysiert. Es wird auf allgemeine sprachliche Merkmale dieser Textsorte verwiesen. In Hotelprospekten lassen sich zwei Funktionen erkennen: die Informationsfunktion und die Appellfunktion. Die Appellfunktion wird meistens durch Adjektive ausgedrückt. Bei der Auswahl der lexikalischen Mittel...

  6. Der Thesaurusgedanke im Grimmschen Worterbuch

    African Journals Online (AJOL)

    Unternehmensgeschichtlich ist es maglich, vier verschiedene Thesauruskonzepte in der Entwick- lung des Deutschen Warterbuches zu unterscheiden. In der ersten Periode wurde das Thesaurus- konzept vom Bemiihen]. Grimms bestimmt, die ganze Fiille der deutschen Sprache in nur einem. Warterbuch zu erschlieBen.

  7. DER 83: outstanding events

    International Nuclear Information System (INIS)

    1984-01-01

    The DER's activity is presented through 82 ''outstanding events''. Each one is a stage in the effort of research and development of the DER. These events concern the following fields: new applications of electric power for customers; environment protection and new energy sources; improvements of electric power production units; electrical materials; electric network planning and control; computer codes. In the production field, one deals more particularly with nuclear reactor safety studies: analysis of the behaviour of different components; reactor safety experiments; reliability of different systems (safety, communications...) [fr

  8. Entanglement-continuous unitary transformations

    Energy Technology Data Exchange (ETDEWEB)

    Sahin, Serkan; Orus, Roman [Institute of Physics, Johannes Gutenberg University, 55099 Mainz (Germany)

    2016-07-01

    In this talk we present a new algorithm for quantum many-body systems using continuous unitary transformations (CUT) and tensor networks (TNs). With TNs we are able to approximate the solution to the flow equations that lie at the heart of continuous unitary transformations. We call this method Entanglement-Continuous Unitary Transformations (eCUT). It allows us to compute expectation values of local observables as well as tensor network representations of ground states and low-energy excited states. An implementation of the method is shown for 1d systems using matrix product operators. We show preliminary results for the 1d transverse-field Ising model to demonstrate the feasibility of the method.

  9. Entropic Entanglement: Information Prison Break

    Directory of Open Access Journals (Sweden)

    Alexander Y. Yosifov

    2017-01-01

    Full Text Available We argue that certain nonviolent local quantum field theory (LQFT modification considered at the global horizon (r=2M of a static spherically symmetric black hole can lead to adiabatic leakage of quantum information in the form of Hawking particles. The source of the modification is (i smooth at r=2M and (ii rapidly vanishing at r≫2M. Furthermore, we restore the unitary evolution by introducing extra quanta which departs slightly from the generic Hawking emission without changing the experience of an infalling observer (no drama. Also, we suggest that a possible interpretation of the Bekenstein-Hawking bound as entanglement entropy may yield a nonsingular dynamical horizon behavior described by black hole thermodynamics. Hence, by treating gravity as a field theory and considering its coupling to the matter fields in the Minkowski vacuum, we derive the conjectured fluctuations of the background geometry of a black hole.

  10. Die Macht der herrschenden Verstehbarkeit über Bedingungen eines nicht-trivialen Zusammenhangs von Anthropologie und Hermeneutik (The power of the dominating understanding. On the conditions of a non-trivial connection between anthropology and hermeneutics

    Directory of Open Access Journals (Sweden)

    Rainer Adolphi

    2012-09-01

    Full Text Available This essay attempts to take up the challenge of the human subject’s understanding in light of contemporary ›systemic‹ superstructures and above all the achievements of Artificial Intelligence. For the construction of a respective theory of human understanding, a number of significant impetuses arise as soon as the argument regarding the conditio humana – in contrast to the one-sided conception of man as an actively interpreting subject – takes into account the fundamental passivity of its condition, as well as its need for comprehensibility. The theory has to consider how the understanding of being a subject develops in acts of comprehension, i.e. the ›self‹ as a secondary formation. (The essay outlines parts of such a theory referencing H. Plessner.The fruitful consequences of such an undertaking are situated in three areas: (1 The complex processes of construction in all modes of understanding. (2 The imposition or demand to understand (versus a complete moralization, i.e. ›understanding‹ as a bestowed kindness or as pertaining to the extend of one’s character. (3 The primordial situation for human beings is that there are already interpretations and ascriptions; from that results the structural susceptibility to ideology within the hermeneutical process (the homo interpretativus is at once the homo ideologicus. To this ideology which masks the real interrelations belongs essentially the ideology of hermeneutical concepts and metaphors themselves which circulatein our times in everyday speech. Considering these three areas, also helps to escape a new fundamentalism which certain hermeneutical modes of thinking harbour within themselves (›anthropologoumena‹ in place of a necessary social theory.

  11. Changes in competence of public authorities in connection with final storage pursuant to the omnibus law on site selection; Veraenderte Behoerdenzustaendigkeiten im Zusammenhang mit der Endlagerung gemaess Artikelgesetz zur Standortsuche

    Energy Technology Data Exchange (ETDEWEB)

    Keienburg, Bettina [Kuemmerlein Rechtsanwaelte und Notare, Essen (Germany)

    2012-12-15

    The omnibus law on site finding and selection for a repository for radioactive waste generating heat, and with amendments to other laws, of June 13, 2012 is to reshuffle fundamentally the competences of public authorities for final storage. The federal government is to assume more responsibilities from former federal state competences. Moreover, most of the existing competences of the Federal Office for Radiation Protection are to be transferred to a federal agency yet to be founded, which is called Federal Office for Nuclear Safety in the present draft legislation. The Federal Office for Radiation Protection will only retain its responsibility as project agent for repositories, and that only in the phases of site exploration and licensing. Afterwards, the duty of final storage in the draft legislation is transferred to a 3rd party. Again in the version of the draft legislation, and unlike present regulations, this 3rd party may only be a company whose sole owner is the federal government, which also is to strengthen the influence of the federal government under aspects of company law. Legislative efforts seeking to strengthen the federal government and its competences by assigning licensing duties for repositories to federal agencies are understandable under feasibility aspects and may even be in the emotional interest of the states and their competent representatives in public authorities who, merely because their work is connected with the disputed topic of final storage, often face attacks and accusations by the public. Nevertheless, the transfer to federal agencies of administrative duties is subject to constitutional limits which must be observed. These constitutional aspects are highlighted in the publication. It is left to the reader to assess the meaningfulness of establishing another independent high-level federal agency in the area of responsibility of the Federal Ministry of the Environment (BMU), i.e. a Federal Office for Nuclear Safety, alongside the competences, which ultimately it will replace, though not the existence of the present independent higher level federal agency within the realm of the BMU, namely the Federal Office for Radiation Protection. (orig.)

  12. Folgeabschätzung einer Einführung von «Smart Metering» im Zusammenhang mit «Smart Grids» in der Schweiz : Schlussbericht vom 5. Juni 2012

    OpenAIRE

    Hettich, Peter; Walther, Simone; Gerlach, Jan; Rechsteiner, Stefan; Keller, Claudia; Dizdarevic-Hasic, Azra

    2012-01-01

    The smart metering impact assessment investigates the costs and benefits of different smart metering rollout scenarios for Switzerland during the period 2015-2035. It is based on the evaluation of smart metering pilot projects and 30 interviews with representatives from aca-demia, industry, and government. Next to the direct and indirect costs and benefits of smart metering, the study assesses the economic and ecologic effects of the investigated scenari-os. The interdisciplinary project team...

  13. Die Bedeutung von Interleukon-1 beo der Entstehung der Knochenerosion

    Directory of Open Access Journals (Sweden)

    Graninger W

    2002-01-01

    Full Text Available Die chronische Polyarthritis ist eine immunmediierte entzündliche Erkrankung, die morphologisch durch eine Zerstörung der Gelenksstrukturen und des subchondralen Knochens charakterisiert ist. Obwohl schon in frühen Krankheitsstadien eine gelenksnahe Osteoporose im Nativröntgen sichtbar wird, ist die Richtigkeit der Diagnose radiologisch erst durch den Nachweis jener typischen Knochenzerstörung zu beweisen, die als Usur oder Erosion bezeichnet wird. An der Grenze zwischen dem entzündlichen Zellinfiltrat, das als Pannus makroskopisch und histologisch imponiert, und dem Gelenksknorpel (cartilage-pannus junction kommt es unter dem Einfluß aktivierter Synoviafibroblasten und ihrer Sekretionsprodukte zum Knorpelzelluntergang und zur Zerstörung der Knorpelmatrix. Gleichzeitig kommt es zur Aktivierung von Osteoklasten, die schließlich in der Entstehung der gelenksnahen Erosion und der subchondralen Knochenzysten resultiert.

  14. On the entanglement entropy for gauge theories

    International Nuclear Information System (INIS)

    Ghosh, Sudip; Soni, Ronak M; Trivedi, Sandip P.

    2015-01-01

    We propose a definition for the entanglement entropy of a gauge theory on a spatial lattice. Our definition applies to any subset of links in the lattice, and is valid for both Abelian and Non-Abelian gauge theories. For ℤ_N and U(1) theories, without matter, our definition agrees with a particular case of the definition given by Casini, Huerta and Rosabal. We also argue that in general, both for Abelian and Non-Abelian theories, our definition agrees with the entanglement entropy calculated using a definition of the replica trick. Our definition, however, does not agree with some standard ways to measure entanglement, like the number of Bell pairs which can be produced by entanglement distillation.

  15. From quantum entanglement to mirror neuron

    International Nuclear Information System (INIS)

    Zak, Michail

    2007-01-01

    It is proposed that two fundamental phenomena: quantum entanglement in physics, and mirror neuron in biopsychology, can be described by using the same mathematical formalism, namely, the feedback from the Liouville equation to equation of motion

  16. Entanglement-assisted quantum feedback control

    Science.gov (United States)

    Yamamoto, Naoki; Mikami, Tomoaki

    2017-07-01

    The main advantage of quantum metrology relies on the effective use of entanglement, which indeed allows us to achieve strictly better estimation performance over the standard quantum limit. In this paper, we propose an analogous method utilizing entanglement for the purpose of feedback control. The system considered is a general linear dynamical quantum system, where the control goal can be systematically formulated as a linear quadratic Gaussian control problem based on the quantum Kalman filtering method; in this setting, an entangled input probe field is effectively used to reduce the estimation error and accordingly the control cost function. In particular, we show that, in the problem of cooling an opto-mechanical oscillator, the entanglement-assisted feedback control can lower the stationary occupation number of the oscillator below the limit attainable by the controller with a coherent probe field and furthermore beats the controller with an optimized squeezed probe field.

  17. Entanglement entropy from the holographic stress tensor

    International Nuclear Information System (INIS)

    Bhattacharyya, Arpan; Sinha, Aninda

    2013-01-01

    We consider entanglement entropy in the context of gauge/gravity duality for conformal field theories in even dimensions. The holographic prescription due to Ryu and Takayanagi (RT) leads to an equation describing how the entangling surface extends into the bulk geometry. We show that setting to zero, the time–time component of the Brown–York stress tensor evaluated on the co-dimension 1 entangling surface, leads to the same equation. By considering a spherical entangling surface as an example, we observe that the Euclidean action methods in AdS/CFT will lead to the RT area functional arising as a counterterm needed to regularize the stress tensor. We present arguments leading to a justification for the minimal area prescription. (paper)

  18. Spin entanglement, decoherence and Bohm's EPR paradox.

    Science.gov (United States)

    Cavalcanti, E G; Drummond, P D; Bachor, H A; Reid, M D

    2009-10-12

    We obtain criteria for entanglement and the EPR paradox for spin-entangled particles and analyse the effects of decoherence caused by absorption and state purity errors. For a two qubit photonic state, entanglement can occur for all transmission efficiencies. In this case, the state preparation purity must be above a threshold value. However, Bohm's spin EPR paradox can be achieved only above a critical level of loss. We calculate a required efficiency of 58%, which appears achievable with current quantum optical technologies. For a macroscopic number of particles prepared in a correlated state, spin entanglement and the EPR paradox can be demonstrated using our criteria for efficiencies eta > 1/3 and eta > 2/3 respectively. This indicates a surprising insensitivity to loss decoherence, in a macroscopic system of ultra-cold atoms or photons.

  19. Entangled biphoton source - property and preparation

    International Nuclear Information System (INIS)

    Shih, Yanhua

    2003-01-01

    One of the most surprising consequences of quantum mechanics is the entanglement of two or more distance particles. Even though there are still questions regarding the fundamental issues of quantum theory, quantum entanglement has started to play important roles in practical engineering applications such as quantum information processing, quantum metrology, quantum imaging and quantum lithography. Two-photon states have been the most popular entangled states in fundamental and applied research. Using spontaneous parametric down conversion as an example, this review introduces the concept of biphoton wavepacket and emphasizes the very different physics associated with the entangled two-photon system (pure state) and with the 'individual' subsystems (statistical mixture). Experimental approaches for Bell state preparation, pumped by continuous wave and ultrashort pulse are discussed

  20. Revisiting entanglement entropy of lattice gauge theories

    Energy Technology Data Exchange (ETDEWEB)

    Hung, Ling-Yan [Department of Physics and Center for Field Theory and Particle Physics, Fudan University,220 Handan Lu, Shanghai 200433 (China); Collaborative Innovation Center of Advanced Microstructures, Fudan University,220 Handan Lu, Shanghai 200433 (China); Wan, Yidun [Perimeter Institute for Theoretical Physics,31 Caroline Street, Waterloo, ON N2L 2Y5 (Canada)

    2015-04-22

    It is realized recently that the entanglement entropy in gauge theories is ambiguous because the Hilbert space cannot be expressed as a simple direct product of Hilbert spaces defined on the two regions; different ways of dividing the Hilbert spaces near the boundary leads to significantly different result, to the extreme that it could annihilate the otherwise finite topological entanglement entropy between two regions altogether. In this article, we first show that the topological entanglement entropy in the Kitaev model http://dx.doi.org/10.1016/S0003-4916(02)00018-0 which is not a true gauge theory, is free of ambiguity. Then, we give a physical interpretation, from the perspectives of what can be measured in an experiment, to the purported ambiguity of true gauge theories, where the topological entanglement arises as redundancy in counting the degrees of freedom along the boundary separating two regions. We generalize these discussions to non-Abelian gauge theories.

  1. Persistent entanglement in the classical limit

    Energy Technology Data Exchange (ETDEWEB)

    Everitt, M J [Centre for Physical Electronics and Quantum Technology, School of Science and Technology, University of Sussex, Falmer, Brighton BN1 9QT (United Kingdom); Clark, T D [Centre for Physical Electronics and Quantum Technology, School of Science and Technology, University of Sussex, Falmer, Brighton BN1 9QT (United Kingdom); Stiffell, P B [Centre for Physical Electronics and Quantum Technology, School of Science and Technology, University of Sussex, Falmer, Brighton BN1 9QT (United Kingdom); Ralph, J F [Department of Electrical and Electronic Engineering, Liverpool University, Brownlow Hill, Liverpool L69 3GJ (United Kingdom); Bulsara, A R [Space and Naval Warfare Systems Center, Code 2363, 53560 Hull Street, San Diego, CA 92152-5001 (United States); Harland, C J [Centre for Physical Electronics and Quantum Technology, School of Science and Technology, University of Sussex, Falmer, Brighton BN1 9QT (United Kingdom)

    2005-02-01

    The apparent difficulty in recovering classical nonlinear dynamics and chaos from standard quantum mechanics has been the subject of a great deal of interest over the last 20 years. For open quantum systems-those coupled to a dissipative environment and/or a measurement device-it has been demonstrated that chaotic-like behaviour can be recovered in the appropriate classical limit. In this paper, we investigate the entanglement generated between two nonlinear oscillators, coupled to each other and to their environment. Entanglement-the inability to factorize coupled quantum systems into their constituent parts-is one of the defining features of quantum mechanics. Indeed, it underpins many of the recent developments in quantum technologies. Here, we show that the entanglement characteristics of two 'classical' states (chaotic and periodic solutions) differ significantly in the classical limit. In particular, we show that significant levels of entanglement are preserved only in the chaotic-like solutions.

  2. Criticality and entanglement in random quantum systems

    International Nuclear Information System (INIS)

    Refael, G; Moore, J E

    2009-01-01

    We review studies of entanglement entropy in systems with quenched randomness, concentrating on universal behavior at strongly random quantum critical points. The disorder-averaged entanglement entropy provides insight into the quantum criticality of these systems and an understanding of their relationship to non-random ('pure') quantum criticality. The entanglement near many such critical points in one dimension shows a logarithmic divergence in subsystem size, similar to that in the pure case but with a different universal coefficient. Such universal coefficients are examples of universal critical amplitudes in a random system. Possible measurements are reviewed along with the one-particle entanglement scaling at certain Anderson localization transitions. We also comment briefly on higher dimensions and challenges for the future.

  3. Converting multilevel nonclassicality into genuine multipartite entanglement

    Science.gov (United States)

    Regula, Bartosz; Piani, Marco; Cianciaruso, Marco; Bromley, Thomas R.; Streltsov, Alexander; Adesso, Gerardo

    2018-03-01

    Characterizing genuine quantum resources and determining operational rules for their manipulation are crucial steps to appraise possibilities and limitations of quantum technologies. Two such key resources are nonclassicality, manifested as quantum superposition between reference states of a single system, and entanglement, capturing quantum correlations among two or more subsystems. Here we present a general formalism for the conversion of nonclassicality into multipartite entanglement, showing that a faithful reversible transformation between the two resources is always possible within a precise resource-theoretic framework. Specializing to quantum coherence between the levels of a quantum system as an instance of nonclassicality, we introduce explicit protocols for such a mapping. We further show that the conversion relates multilevel coherence and multipartite entanglement not only qualitatively, but also quantitatively, restricting the amount of entanglement achievable in the process and in particular yielding an equality between the two resources when quantified by fidelity-based geometric measures.

  4. Orbital-angular-momentum entanglement in turbulence

    CSIR Research Space (South Africa)

    Hamadou Ibrahim, A

    2013-06-01

    Full Text Available The turbulence-induced decay of orbital-angular-momentum (OAM) entanglement between two photons is investigated numerically and experimentally. To compare our resultswith previouswork,we simulate the turbulent atmosphere with a single phase screen...

  5. Entanglement degradation in depolarizing light scattering

    International Nuclear Information System (INIS)

    Aiello, A.; Woerdman, J.P.

    2005-01-01

    Full text: In the classical regime, when a beam of light is scattered by a medium, it may emerge partially or completely depolarized depending on the optical properties of the medium. Correspondingly, in the quantum regime, when an entangled two-photon pair is scattered, the classical depolarization may result in an entanglement degradation. Here, relations between photon scattering, entanglement and multi-mode detection are investigated. We establish a general framework in which one- and two-photon elastic scattering processes can be discussed, and we focus on the study of the intrinsic entanglement degradation caused by a multi-mode detection. We show that any multi-mode scattered state cannot maximally violate the Bell-CHSH inequality because of the momentum spread. The results presented here have general validity and can be applied to both deterministic and random scattering processes. (author)

  6. Machine learning spatial geometry from entanglement features

    Science.gov (United States)

    You, Yi-Zhuang; Yang, Zhao; Qi, Xiao-Liang

    2018-02-01

    Motivated by the close relations of the renormalization group with both the holography duality and the deep learning, we propose that the holographic geometry can emerge from deep learning the entanglement feature of a quantum many-body state. We develop a concrete algorithm, call the entanglement feature learning (EFL), based on the random tensor network (RTN) model for the tensor network holography. We show that each RTN can be mapped to a Boltzmann machine, trained by the entanglement entropies over all subregions of a given quantum many-body state. The goal is to construct the optimal RTN that best reproduce the entanglement feature. The RTN geometry can then be interpreted as the emergent holographic geometry. We demonstrate the EFL algorithm on a 1D free fermion system and observe the emergence of the hyperbolic geometry (AdS3 spatial geometry) as we tune the fermion system towards the gapless critical point (CFT2 point).

  7. Projected entangled pair states: status and prospects

    Energy Technology Data Exchange (ETDEWEB)

    Verstraete, Frank [Universitaet Wien (Austria)

    2008-07-01

    We report on the progress made to extend the density matrix renormalization group to higher dimensions, discuss the underlying theory of projected entangled pair states (PEPS) and illustrate its potential on the hand of a few examples.

  8. Quantum Entanglement and Reduced Density Matrices

    Science.gov (United States)

    Purwanto, Agus; Sukamto, Heru; Yuwana, Lila

    2018-05-01

    We investigate entanglement and separability criteria of multipartite (n-partite) state by examining ranks of its reduced density matrices. Firstly, we construct the general formula to determine the criterion. A rank of origin density matrix always equals one, meanwhile ranks of reduced matrices have various ranks. Next, separability and entanglement criterion of multipartite is determined by calculating ranks of reduced density matrices. In this article we diversify multipartite state criteria into completely entangled state, completely separable state, and compound state, i.e. sub-entangled state and sub-entangledseparable state. Furthermore, we also shorten the calculation proposed by the previous research to determine separability of multipartite state and expand the methods to be able to differ multipartite state based on criteria above.

  9. Testing for entanglement with periodic coarse graining

    Science.gov (United States)

    Tasca, D. S.; Rudnicki, Łukasz; Aspden, R. S.; Padgett, M. J.; Souto Ribeiro, P. H.; Walborn, S. P.

    2018-04-01

    Continuous-variable systems find valuable applications in quantum information processing. To deal with an infinite-dimensional Hilbert space, one in general has to handle large numbers of discretized measurements in tasks such as entanglement detection. Here we employ the continuous transverse spatial variables of photon pairs to experimentally demonstrate entanglement criteria based on a periodic structure of coarse-grained measurements. The periodization of the measurements allows an efficient evaluation of entanglement using spatial masks acting as mode analyzers over the entire transverse field distribution of the photons and without the need to reconstruct the probability densities of the conjugate continuous variables. Our experimental results demonstrate the utility of the derived criteria with a success rate in entanglement detection of ˜60 % relative to 7344 studied cases.

  10. Entangled biphoton source - property and preparation

    CERN Document Server

    Shih, Y

    2003-01-01

    One of the most surprising consequences of quantum mechanics is the entanglement of two or more distance particles. Even though there are still questions regarding the fundamental issues of quantum theory, quantum entanglement has started to play important roles in practical engineering applications such as quantum information processing, quantum metrology, quantum imaging and quantum lithography. Two-photon states have been the most popular entangled states in fundamental and applied research. Using spontaneous parametric down conversion as an example, this review introduces the concept of biphoton wavepacket and emphasizes the very different physics associated with the entangled two-photon system (pure state) and with the 'individual' subsystems (statistical mixture). Experimental approaches for Bell state preparation, pumped by continuous wave and ultrashort pulse are discussed.

  11. Classical statistical mechanics approach to multipartite entanglement

    Energy Technology Data Exchange (ETDEWEB)

    Facchi, P [Dipartimento di Matematica, Universita di Bari, I-70125 Bari (Italy); Florio, G; Pascazio, S [Istituto Nazionale di Fisica Nucleare, Sezione di Bari, I-70126 Bari (Italy); Marzolino, U [Dipartimento di Fisica, Universita di Trieste, and Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34014 Trieste (Italy); Parisi, G [Dipartimento di Fisica, Universita di Roma ' La Sapienza' , Piazzale Aldo Moro 2, Centre for Statistical Mechanics and Complexity (SMC), CNR-INFM (Italy)

    2010-06-04

    We characterize the multipartite entanglement of a system of n qubits in terms of the distribution function of the bipartite purity over balanced bipartitions. We search for maximally multipartite entangled states, whose average purity is minimal, and recast this optimization problem into a problem of statistical mechanics, by introducing a cost function, a fictitious temperature and a partition function. By investigating the high-temperature expansion, we obtain the first three moments of the distribution. We find that the problem exhibits frustration.

  12. Classical statistical mechanics approach to multipartite entanglement

    Science.gov (United States)

    Facchi, P.; Florio, G.; Marzolino, U.; Parisi, G.; Pascazio, S.

    2010-06-01

    We characterize the multipartite entanglement of a system of n qubits in terms of the distribution function of the bipartite purity over balanced bipartitions. We search for maximally multipartite entangled states, whose average purity is minimal, and recast this optimization problem into a problem of statistical mechanics, by introducing a cost function, a fictitious temperature and a partition function. By investigating the high-temperature expansion, we obtain the first three moments of the distribution. We find that the problem exhibits frustration.

  13. Classical statistical mechanics approach to multipartite entanglement

    International Nuclear Information System (INIS)

    Facchi, P; Florio, G; Pascazio, S; Marzolino, U; Parisi, G

    2010-01-01

    We characterize the multipartite entanglement of a system of n qubits in terms of the distribution function of the bipartite purity over balanced bipartitions. We search for maximally multipartite entangled states, whose average purity is minimal, and recast this optimization problem into a problem of statistical mechanics, by introducing a cost function, a fictitious temperature and a partition function. By investigating the high-temperature expansion, we obtain the first three moments of the distribution. We find that the problem exhibits frustration.

  14. Entanglement detection via tighter local uncertainty relations

    International Nuclear Information System (INIS)

    Zhang Chengjie; Zhang Yongsheng; Guo Guangcan; Nha, Hyunchul

    2010-01-01

    We propose an entanglement criterion based on local uncertainty relations (LURs) in a stronger form than the original LUR criterion introduced by Hofmann and Takeuchi [H. F. Hofmann and S. Takeuchi, Phys. Rev. A 68, 032103 (2003)]. Using arbitrarily chosen operators (A k ) and (B k ) of subsystems A and B, the tighter LUR criterion, which may be used not only for discrete variables but also for continuous variables, can detect more entangled states than the original criterion.

  15. Monogamy inequality for distributed gaussian entanglement.

    Science.gov (United States)

    Hiroshima, Tohya; Adesso, Gerardo; Illuminati, Fabrizio

    2007-02-02

    We show that for all n-mode Gaussian states of continuous variable systems, the entanglement shared among n parties exhibits the fundamental monogamy property. The monogamy inequality is proven by introducing the Gaussian tangle, an entanglement monotone under Gaussian local operations and classical communication, which is defined in terms of the squared negativity in complete analogy with the case of n-qubit systems. Our results elucidate the structure of quantum correlations in many-body harmonic lattice systems.

  16. Multipartite secret key distillation and bound entanglement

    International Nuclear Information System (INIS)

    Augusiak, Remigiusz; Horodecki, Pawel

    2009-01-01

    Recently it has been shown that quantum cryptography beyond pure entanglement distillation is possible and a paradigm for the associated protocols has been established. Here we systematically generalize the whole paradigm to the multipartite scenario. We provide constructions of new classes of multipartite bound entangled states, i.e., those with underlying twisted Greenberger-Horne-Zeilinger (GHZ) structure and nonzero distillable cryptographic key. We quantitatively estimate the key from below with the help of the privacy squeezing technique.

  17. Entanglement in mesoscopic structures: Role of projection

    OpenAIRE

    Beenakker, C.W.J.; Lebedev, A.V.; Blatter, G.; Lesovik, G.B.

    2004-01-01

    We present a theoretical analysis of the appearance of entanglement in non-interacting mesoscopic structures. Our setup involves two oppositely polarized sources injecting electrons of opposite spin into the two incoming leads. The mixing of these polarized streams in an ideal four-channel beam splitter produces two outgoing streams with particular tunable correlations. A Bell inequality test involving cross-correlated spin-currents in opposite leads signals the presence of spin-entanglement ...

  18. Multipartite electronic entanglement purification with charge detection

    Energy Technology Data Exchange (ETDEWEB)

    Sheng Yubo [Department of Physics, Tsinghua University, Beijing 100084 (China); Deng, Fu-Guo [Department of Physics, Beijing Normal University, Beijing 100875 (China); Long Guilu, E-mail: gllong@tsinghua.edu.c [Department of Physics, Tsinghua University, Beijing 100084 (China); Key Laboratory for Atomic and Molecular NanoSciences, Tsinghua University, Beijing 100084 (China); Tsinghua National Laboratory for Information Science and Technology, Beijing 100084 (China)

    2011-01-17

    We present a multipartite entanglement purification scheme in a Greenberger-Horne-Zeilinger state for electrons based on their spins and their charges. This scheme works for purification with two steps, i.e., bit-flip error correction and phase-flip error correction. By repeating these two steps, the parties in quantum communication can get some high-fidelity multipartite entangled electronic systems.

  19. Quantum Blockchain using entanglement in time

    OpenAIRE

    Rajan, Del; Visser, Matt

    2018-01-01

    A conceptual design for a quantum blockchain is proposed. Our method involves encoding the blockchain into a temporal GHZ (Greenberger-Horne-Zeilinger) state of photons that do not simultaneously coexist. It is shown that the entanglement in time, as opposed to an entanglement in space, provides the crucial quantum advantage. All the subcomponents of this system have already been shown to be experimentally realized. Perhaps more shockingly, our encoding procedure can be interpreted as non-cla...

  20. Detection of entanglement with few local measurements

    International Nuclear Information System (INIS)

    Guehne, O.; Hyllus, P.; Bruss, D.; Lewenstein, M.; Sanpera, A.; Ekert, A.; Macchiavello, C.

    2002-01-01

    We introduce a general method for the experimental detection of entanglement by performing only few local measurements, assuming some prior knowledge of the density matrix. The idea is based on the minimal decomposition of witness operators into a pseudomixture of local operators. We discuss an experimentally relevant case of two qubits, and show an example how bound entanglement can be detected with few local measurements

  1. Detection of entanglement with few local measurements

    OpenAIRE

    Guehne, O.; Hyllus, P.; Bruss, D.; Ekert, A.; Lewenstein, M.; Macchiavello, C.; Sanpera, A.

    2002-01-01

    We introduce a general method for the experimental detection of entanglement by performing only few local measurements, assuming some prior knowledge of the density matrix. The idea is based on the minimal decomposition of witness operators into a pseudo-mixture of local operators. We discuss an experimentally relevant case of two qubits, and show an example how bound entanglement can be detected with few local measurements.

  2. Detection of entanglement with few local measurements

    Science.gov (United States)

    Gühne, O.; Hyllus, P.; Bruß, D.; Ekert, A.; Lewenstein, M.; Macchiavello, C.; Sanpera, A.

    2002-12-01

    We introduce a general method for the experimental detection of entanglement by performing only few local measurements, assuming some prior knowledge of the density matrix. The idea is based on the minimal decomposition of witness operators into a pseudomixture of local operators. We discuss an experimentally relevant case of two qubits, and show an example how bound entanglement can be detected with few local measurements.

  3. Evaluiertes Training von Führungskompetenzen in der medizinischen Aus- und Weiterbildung [Training of Leadership Skills in Medical Education

    Directory of Open Access Journals (Sweden)

    Fischer, Martin R.

    2013-11-01

    Zusammenarbeit in Teams ist eine wichtige Voraussetzung für qualitativ hochwertige Versorgung im Gesundheitswesen. In diesem Zusammenhang spielen auch Führungskompetenzen von Ärztinnen und Ärzten im klinischen Alltag eine wichtige Rolle. Bisher wurde die Entwicklung von Führungskompetenzen in medizinischen Curricula in der Aus- und Weiterbildung von Ärztinnen und Ärzten jedoch kaum systematisch abgebildet. Die Entwicklung adäquater und effektiver Trainingsmethoden für die Vermittlung von Führungskompetenzen ist daher wünschenswert. Ziel: Das Review soll vorliegende Ergebnisse der Literatur zu Trainings von Führungskompetenzen in der Medizin zusammenfassen und integrieren, um zukünftige Forschung und Trainingsentwicklung anzuregen. Methode: Die Datenbanken PubMED, ERIC, PsycArticles, PsycINFO, PSYNDEX und dem Academic search complete durch EBSCOhost wurden auf Deutsch und Englisch nach Trainings von Führungskompetenzen in der Medizin durchsucht. Relevante Artikel wurden identifiziert und die Studienergebnisse hinsichtlich des zugrundeliegenden Führungsverständnisses, der Zielgruppe und Teilnehmeranzahl, der zeitlichen Ressourcen, sowie der Inhalte und Methoden des Trainings, des Evaluationsdesigns und der berichteten Trainingseffekte zusammengefasst. Ergebnisse: Auf acht Studien trafen alle Einschluss- und kein Ausschlusskriterium zu. Die Trainings selbst sowie die thematisierten Führungskompetenzen differenzieren jedoch stark voneinander. Die Trainingsdesigns beinhalten im Schwerpunkt die theoretische Auseinandersetzung mit dem Thema Führung sowie die Diskussion von Fallstudien aus der Praxis. Die Dauer der Trainings reicht von mehrstündigen bis hin zu mehrjährigen Veranstaltungen. Die selbst eingeschätzte Reaktion der Teilnehmer auf alle Trainings war positiv; es fand jedoch bisher keine systematische Überprüfung des Trainingserfolgs in Bezug auf konkrete Verhaltensänderungen der Teilnehmer statt.Schlussfolgerungen: Es bedarf weiterer Forschung, um die

  4. Effects of dipole—dipole interaction on entanglement transfer

    International Nuclear Information System (INIS)

    Guo Hong; Xiong Hengna

    2008-01-01

    A system consisting of two different atoms interacting with a two-mode vacuum, where each atom is resonant only with one cavity mode, is considered. The effects of dipole—dipole (dd) interaction between two atoms on the atom-atom entanglement and mode-mode entanglement are investigated. For a weak dd interaction, when the atoms are initially separable, the entanglement between them can be induced by the dd interaction, and the entanglement transfer between the atoms and the modes occurs efficiently; when the atoms are initially entangled, the entanglement transfer is almost not influenced by the dd interaction. However, for a strong dd interaction, it is difficult to transfer the entanglement from the atoms to the modes, but the atom-atom entanglement can be maintained when the atoms are initially entangled

  5. Searching for highly entangled multi-qubit states

    International Nuclear Information System (INIS)

    Brown, Iain D K; Stepney, Susan; Sudbery, Anthony; Braunstein, Samuel L

    2005-01-01

    We present a simple numerical optimization procedure to search for highly entangled states of 2, 3, 4 and 5 qubits. We develop a computationally tractable entanglement measure based on the negative partial transpose criterion, which can be applied to quantum systems of an arbitrary number of qubits. The search algorithm attempts to optimize this entanglement cost function to find the maximal entanglement in a quantum system. We present highly entangled 4-qubit and 5-qubit states discovered by this search. We show that the 4-qubit state is not quite as entangled, according to two separate measures, as the conjectured maximally entangled Higuchi-Sudbery state. Using this measure, these states are more highly entangled than the 4-qubit and 5-qubit GHZ states. We also present a conjecture about the NPT measure, inspired by some of our numerical results, that the single-qubit reduced states of maximally entangled states are all totally mixed

  6. Ledelse der giver mening

    DEFF Research Database (Denmark)

    Conrad, Torsten

    2014-01-01

    supervision i praksis (Joyce & Showers, 2002). Artiklen sigter mod at bidrage med en øget forståelse af implementeringen af politiske beslutninger ved at belyse de forhold, der præger implementeringen med særligt fokus på skoleledelsen, medarbejderne og deres relation. Artiklen søger også at belyse, hvordan...

  7. Der digitalisierte Forscher

    Directory of Open Access Journals (Sweden)

    Kröll, Thomas

    2017-12-01

    Full Text Available Im 21. Jahrhundert ist der akademische Forscher nicht nur zunehmend digital informiert; die gesetzlich gebotene Evaluierung seiner Forschungsleistungen ist mitunter auch eine digital abgestützte. Dies bedeutet nicht nur Vorteile, sondern auch Risiken für den akademischen Forscher.

  8. Wasserpflanzen in der Natur

    DEFF Research Database (Denmark)

    Pedersen, Ole; Christensen, Claus

    2011-01-01

    Unsere Aquarienpflanzen kommen in der Natur vor oder sind Zuchtformen natürlicher Arten. Dennoch konnten erst sehr wenige Aquarianer diese Pflanzen in ihrer natürlichen Umgebung beobachten. Oft stellten sie fest, dass die Pflanzen meist ganz anders aussehen als im Aquarium. Neben einem ständigen...

  9. Der Shakeout im Industrielebenszyklus

    DEFF Research Database (Denmark)

    Croonenbroeck, Carsten; Grimpe, Christoph; Stadtmann, Georg

    In vormals aufstrebenden Branchen wie z. B. der Solarindustrie kommt es plötzlich zu einem massiven Austritt selbst großer Marktteilnehmer. Warum? Dieser Artikel zeigt, wie mit mikroökonomischen Überlegungen argumentiert werden kann, um die Anzahl an Unternehmen in einem Markt zu bestimmen. Es wi...

  10. Der Dichter Roman Svendborg

    DEFF Research Database (Denmark)

    Schweppenhäuser, Jakob

    2016-01-01

    Roman Svendborg? Mein Großvater, Hermann Schweppenhäuser, schenkte mir vor einigen Jahren einmal einen Gedichtband, dessen Verfasser mir bis lang noch nicht bekannt war. Damals noch ein junger dänischer Student der Skandinavistik waren mir schließlich nicht alle deutschsprachigen Dichter geläufig...

  11. Der digitalisierte Steuerzahler

    Directory of Open Access Journals (Sweden)

    Kirchhof, Gregor

    2017-12-01

    Full Text Available Die nach dem österreichischen Vorbild beschlossene Modernisierung des Besteuerungsverfahrens in Deutschland verletzt solange das Grundgesetz, bis ein Ertragsteuerrecht in Kraft tritt, das gesetzeskonform und gleichheitsgerecht digital angewandt werden kann. Auch die steuerlichen Erhebungslasten fordern eine Vereinfachung des materiellen Rechts: Selbst wenn die Mitwirkungspflichten, die Lenkungswirkungen, auch die steuerstrafrechtlichen Vorgaben und datenrechtlichen Lasten isoliert betrachtet noch zumutbar wären, verletzt jedenfalls deren Kumulation das verfassungsrechtliche Maß. Schließlich wird der Kampf gegen „aggressive Steuerplanungen“ internationaler Unternehmen nur erfolgreich sein, wenn das anzuwendende Steuerrecht grundlegend vereinfacht wird. Diese Reformforderungen werden durch die historischen Motive der Soll-Ertragsbesteuerung bestätigt: Steuerhinterziehungen sollten vermieden, die Privatsphäre der Steuerpflichtigen sollte geschont und jeder gleichheitsgerecht zur Steuer herangezogen werden. Das geltende Steuerrecht belastet zu Recht den tatsächlichen, den Ist-Ertrag. Die geltende unübersichtliche Konkretisierung dieses Ausgangspunktes durch Elemente der Soll-Ertragsbesteuerung ist aber in einer grundlegenden Vereinfachung des Steuerrechts zu rationalisieren und zum System zu machen.

  12. Fiber transport of spatially entangled photons

    Science.gov (United States)

    Löffler, W.; Eliel, E. R.; Woerdman, J. P.; Euser, T. G.; Scharrer, M.; Russell, P.

    2012-03-01

    High-dimensional entangled photons pairs are interesting for quantum information and cryptography: Compared to the well-known 2D polarization case, the stronger non-local quantum correlations could improve noise resistance or security, and the larger amount of information per photon increases the available bandwidth. One implementation is to use entanglement in the spatial degree of freedom of twin photons created by spontaneous parametric down-conversion, which is equivalent to orbital angular momentum entanglement, this has been proven to be an excellent model system. The use of optical fiber technology for distribution of such photons has only very recently been practically demonstrated and is of fundamental and applied interest. It poses a big challenge compared to the established time and frequency domain methods: For spatially entangled photons, fiber transport requires the use of multimode fibers, and mode coupling and intermodal dispersion therein must be minimized not to destroy the spatial quantum correlations. We demonstrate that these shortcomings of conventional multimode fibers can be overcome by using a hollow-core photonic crystal fiber, which follows the paradigm to mimic free-space transport as good as possible, and are able to confirm entanglement of the fiber-transported photons. Fiber transport of spatially entangled photons is largely unexplored yet, therefore we discuss the main complications, the interplay of intermodal dispersion and mode mixing, the influence of external stress and core deformations, and consider the pros and cons of various fiber types.

  13. Remarks on entanglement entropy in string theory

    Science.gov (United States)

    Balasubramanian, Vijay; Parrikar, Onkar

    2018-03-01

    Entanglement entropy for spatial subregions is difficult to define in string theory because of the extended nature of strings. Here we propose a definition for bosonic open strings using the framework of string field theory. The key difference (compared to ordinary quantum field theory) is that the subregion is chosen inside a Cauchy surface in the "space of open string configurations." We first present a simple calculation of this entanglement entropy in free light-cone string field theory, ignoring subtleties related to the factorization of the Hilbert space. We reproduce the answer expected from an effective field theory point of view, namely a sum over the one-loop entanglement entropies corresponding to all the particle-excitations of the string, and further show that the full string theory regulates ultraviolet divergences in the entanglement entropy. We then revisit the question of factorization of the Hilbert space by analyzing the covariant phase-space associated with a subregion in Witten's covariant string field theory. We show that the pure gauge (i.e., BRST exact) modes in the string field become dynamical at the entanglement cut. Thus, a proper definition of the entropy must involve an extended Hilbert space, with new stringy edge modes localized at the entanglement cut.

  14. Bipartite entanglement in continuous variable cluster states

    Energy Technology Data Exchange (ETDEWEB)

    Cable, Hugo; Browne, Daniel E, E-mail: cqthvc@nus.edu.s, E-mail: d.browne@ucl.ac.u [Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543 (Singapore)

    2010-11-15

    A study of the entanglement properties of Gaussian cluster states, proposed as a universal resource for continuous variable (CV) quantum computing is presented in this paper. The central aim is to compare mathematically idealized cluster states defined using quadrature eigenstates, which have infinite squeezing and cannot exist in nature, with Gaussian approximations that are experimentally accessible. Adopting widely used definitions, we first review the key concepts, by analysing a process of teleportation along a CV quantum wire in the language of matrix product states. Next we consider the bipartite entanglement properties of the wire, providing analytic results. We proceed to grid cluster states, which are universal for the qubit case. To extend our analysis of the bipartite entanglement, we adopt the entropic-entanglement width, a specialized entanglement measure introduced recently by Van den Nest et al (2006 Phys. Rev. Lett. 97 150504), adapting their definition to the CV context. Finally, we consider the effects of photonic loss, extending our arguments to mixed states. Cumulatively our results point to key differences in the properties of idealized and Gaussian cluster states. Even modest loss rates are found to strongly limit the amount of entanglement. We discuss the implications for the potential of CV analogues for measurement-based quantum computation.

  15. Multiple quantum spin dynamics of entanglement

    International Nuclear Information System (INIS)

    Doronin, Serge I.

    2003-01-01

    The dynamics of entanglement is investigated on the basis of exactly solvable models of multiple quantum (MQ) NMR spin dynamics. It is shown that the time evolution of MQ coherences of systems of coupled nuclear spins in solids is directly connected with dynamics of the quantum entanglement. We studied analytically the dynamics of entangled states for two- and three-spin systems coupled by the dipole-dipole interaction. In this case the dynamics of the quantum entanglement is uniquely determined by the time evolution of MQ coherences of the second order. The real part of the density matrix describing MQ dynamics in solids is responsible for MQ coherences of the zeroth order while its imaginary part is responsible for the second order. Thus, one can conclude that the dynamics of the entanglement is connected with transitions from the real part of the density matrix to the imaginary one, and vice versa. A pure state which generalizes the Greenberger-Horne-Zeilinger (GHZ) and W states is found. Different measures of the entanglement of this state are analyzed for tripartite systems

  16. Entangled photons from single atoms and molecules

    Science.gov (United States)

    Nordén, Bengt

    2018-05-01

    The first two-photon entanglement experiment performed 50 years ago by Kocher and Commins (KC) provided isolated pairs of entangled photons from an atomic three-state fluorescence cascade. In view of questioning of Bell's theorem, data from these experiments are re-analyzed and shown sufficiently precise to confirm quantum mechanical and dismiss semi-classical theory without need for Bell's inequalities. Polarization photon correlation anisotropy (A) is useful: A is near unity as predicted quantum mechanically and well above the semi-classic range, 0 ⩽ A ⩽ 1 / 2 . Although yet to be found, one may envisage a three-state molecule emitting entangled photon pairs, in analogy with the KC atomic system. Antibunching in fluorescence from single molecules in matrix and entangled photons from quantum dots promise it be possible. Molecules can have advantages to parametric down-conversion as the latter photon distribution is Poissonian and unsuitable for producing isolated pairs of entangled photons. Analytical molecular applications of entangled light are also envisaged.

  17. Quantum teleportation and multi-photon entanglement

    International Nuclear Information System (INIS)

    Pan, J.-W.

    1999-08-01

    The present thesis is the result of theoretical and experimental work on the physics of multiparticle interference. The theoretical results show that a quantum network with simple quantum logic gates and a handful of qubits enables one to control and manipulate quantum entanglement. Because of the present absence of quantum gate for two independently produced photons, in the mean time we also present a practical way to generate and identify multiparticle entangled state. The experimental work has thoroughly developed the necessary techniques to study novel multiparticle interference phenomena. By making use of the pulsed source for polarization entangled photon pairs, in this thesis we report for the first time the experimental realization of quantum teleportation, of entanglement swapping and of production of these-particle entanglement. Using the three-particle entanglement source, here we also present the first experimental realization of a test of local realism without inequalities. The methods developed in these experiments are of great significance both for exploring the field of quantum information and for future experiments on the fundamental tests of quantum mechanics. (author)

  18. Interuniversal entanglement in a cyclic multiverse

    Science.gov (United States)

    Robles-Pérez, Salvador; Balcerzak, Adam; Dąbrowski, Mariusz P.; Krämer, Manuel

    2017-04-01

    We study scenarios of parallel cyclic multiverses which allow for a different evolution of the physical constants, while having the same geometry. These universes are classically disconnected, but quantum-mechanically entangled. Applying the thermodynamics of entanglement, we calculate the temperature and the entropy of entanglement. It emerges that the entropy of entanglement is large at big bang and big crunch singularities of the parallel universes as well as at the maxima of the expansion of these universes. The latter seems to confirm earlier studies that quantum effects are strong at turning points of the evolution of the universe performed in the context of the timeless nature of the Wheeler-DeWitt equation and decoherence. On the other hand, the entropy of entanglement at big rip singularities is going to zero despite its presumably quantum nature. This may be an effect of total dissociation of the universe structures into infinitely separated patches violating the null energy condition. However, the temperature of entanglement is large/infinite at every classically singular point and at maximum expansion and seems to be a better measure of quantumness.

  19. First law of entanglement rates from holography

    Science.gov (United States)

    O'Bannon, Andy; Probst, Jonas; Rodgers, Ronnie; Uhlemann, Christoph F.

    2017-09-01

    For a perturbation of the state of a conformal field theory (CFT), the response of the entanglement entropy is governed by the so-called "first law" of entanglement entropy, in which the change in entanglement entropy is proportional to the change in energy. Whether such a first law holds for other types of perturbations, such as a change to the CFT Lagrangian, remains an open question. We use holography to study the evolution in time t of entanglement entropy for a CFT driven by a t -linear source for a conserved U (1 ) current or marginal scalar operator. We find that although the usual first law of entanglement entropy may be violated, a first law for the rates of change of entanglement entropy and energy still holds. More generally, we prove that this first law for rates holds in holography for any asymptotically (d +1 )-dimensional anti-de Sitter metric perturbation whose t dependence first appears at order zd in the Fefferman-Graham expansion about the boundary at z =0 .

  20. Entanglement entropy and nonabelian gauge symmetry

    International Nuclear Information System (INIS)

    Donnelly, William

    2014-01-01

    Entanglement entropy has proven to be an extremely useful concept in quantum field theory. Gauge theories are of particular interest, but for these systems the entanglement entropy is not clearly defined because the physical Hilbert space does not factor as a tensor product according to regions of space. Here we review a definition of entanglement entropy that applies to abelian and nonabelian lattice gauge theories. This entanglement entropy is obtained by embedding the physical Hilbert space into a product of Hilbert spaces associated to regions with boundary. The latter Hilbert spaces include degrees of freedom on the entangling surface that transform like surface charges under the gauge symmetry. These degrees of freedom are shown to contribute to the entanglement entropy, and the form of this contribution is determined by the gauge symmetry. We test our definition using the example of two-dimensional Yang–Mills theory, and find that it agrees with the thermal entropy in de Sitter space, and with the results of the Euclidean replica trick. We discuss the possible implications of this result for more complicated gauge theories, including quantum gravity. (paper)

  1. Generalized Entanglement Entropies of Quantum Designs

    Science.gov (United States)

    Liu, Zi-Wen; Lloyd, Seth; Zhu, Elton Yechao; Zhu, Huangjun

    2018-03-01

    The entanglement properties of random quantum states or dynamics are important to the study of a broad spectrum of disciplines of physics, ranging from quantum information to high energy and many-body physics. This Letter investigates the interplay between the degrees of entanglement and randomness in pure states and unitary channels. We reveal strong connections between designs (distributions of states or unitaries that match certain moments of the uniform Haar measure) and generalized entropies (entropic functions that depend on certain powers of the density operator), by showing that Rényi entanglement entropies averaged over designs of the same order are almost maximal. This strengthens the celebrated Page's theorem. Moreover, we find that designs of an order that is logarithmic in the dimension maximize all Rényi entanglement entropies and so are completely random in terms of the entanglement spectrum. Our results relate the behaviors of Rényi entanglement entropies to the complexity of scrambling and quantum chaos in terms of the degree of randomness, and suggest a generalization of the fast scrambling conjecture.

  2. Discussion of entanglement entropy in quantum gravity

    International Nuclear Information System (INIS)

    Ma, Chen-Te

    2018-01-01

    We study entanglement entropy in gravity theory with quantum effects. A simplest model is a two dimensional Einstein gravity theory. We use an n-sheet manifold to obtain an area term of entanglement entropy by summing over all background fields. Based on AdS/CFT correspondence, strongly coupled conformal field theory is expected to describe perturbative quantum gravity theory. An ultraviolet complete quantum gravity theory should not depend on a choice of an entangling surface. To analysis the problem explicitly, we analyze two dimensional conformal field theory. We find that a coefficient of a universal term of entanglement entropy is independent of a choice of an entangling surface in two dimensional conformal field theory for one interval to show a tentative evidence. Finally, we discuss that translational invariance in a quantum system at zero temperature, size goes to infinity and no mass scales, except for cut-off, possibly be a necessary condition in quantum gravity theory by ruing out a volume law of entanglement entropy. (copyright 2018 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. Entanglement in a simple quantum phase transition

    International Nuclear Information System (INIS)

    Osborne, Tobias J.; Nielsen, Michael A.

    2002-01-01

    What entanglement is present in naturally occurring physical systems at thermal equilibrium? Most such systems are intractable and it is desirable to study simple but realistic systems that can be solved. An example of such a system is the one-dimensional infinite-lattice anisotropic XY model. This model is exactly solvable using the Jordan-Wigner transform, and it is possible to calculate the two-site reduced density matrix for all pairs of sites. Using the two-site density matrix, the entanglement of formation between any two sites is calculated for all parameter values and temperatures. We also study the entanglement in the transverse Ising model, a special case of the XY model, which exhibits a quantum phase transition. It is found that the next-nearest-neighbor entanglement (though not the nearest-neighbor entanglement) is a maximum at the critical point. Furthermore, we show that the critical point in the transverse Ising model corresponds to a transition in the behavior of the entanglement between a single site and the remainder of the lattice

  4. Mode entanglement of Gaussian fermionic states

    Science.gov (United States)

    Spee, C.; Schwaiger, K.; Giedke, G.; Kraus, B.

    2018-04-01

    We investigate the entanglement of n -mode n -partite Gaussian fermionic states (GFS). First, we identify a reasonable definition of separability for GFS and derive a standard form for mixed states, to which any state can be mapped via Gaussian local unitaries (GLU). As the standard form is unique, two GFS are equivalent under GLU if and only if their standard forms coincide. Then, we investigate the important class of local operations assisted by classical communication (LOCC). These are central in entanglement theory as they allow one to partially order the entanglement contained in states. We show, however, that there are no nontrivial Gaussian LOCC (GLOCC) among pure n -partite (fully entangled) states. That is, any such GLOCC transformation can also be accomplished via GLU. To obtain further insight into the entanglement properties of such GFS, we investigate the richer class of Gaussian stochastic local operations assisted by classical communication (SLOCC). We characterize Gaussian SLOCC classes of pure n -mode n -partite states and derive them explicitly for few-mode states. Furthermore, we consider certain fermionic LOCC and show how to identify the maximally entangled set of pure n -mode n -partite GFS, i.e., the minimal set of states having the property that any other state can be obtained from one state inside this set via fermionic LOCC. We generalize these findings also to the pure m -mode n -partite (for m >n ) case.

  5. Schriftstellerinnen der DDR und feministisches Bewußtsein im Staatssozialismus GDR Women Authors and Feminist Consciousness During State Socialism

    Directory of Open Access Journals (Sweden)

    Eva Kaufmann

    2001-11-01

    Full Text Available Seit den 1960er Jahren produzierten Schriftstellerinnen in der DDR wie Christa Wolf, Irmtraud Morgner, Sarah Kirsch, Brigitte Reimann, Charlotte Worgitzky, Lia Pirskawetz, und Maya Wiens eine vielfältige Literatur zu frauenrelevanten Themen. Den Obertitel „The Promised Land“ (das gelobte Land hat Lorna Martens Irmtraud Morgner entlehnt, der Autorin, die sie neben Christa Wolf als wichtigste Zeugin für „feminist writing“ in der DDR betrachtet. In Morgners Roman Leben und Abenteuer der Trobadora Beatriz steht der Begriff „gelobtes Land“ bezogen auf die DDR in einem ironischen Zusammenhang. Mit simplem Jaja oder Neinnein ist diesem „Ort des Wunderbaren“ (Morgner nicht beizukommen. Vergleichbares signalisiert auch das Fragezeichen, das Martens hinter den Begriff „Promised Land“ setzt. Der anspielungsreiche Verweis auf das Land erscheint auch insofern nützlich, als die Eigenart feministischen Schreibens genauer zu fassen ist, wenn über das Land selbst, namentlich seine Frauenpolitik, Auskünfte gegeben werden. Lorna Martens möchte herausfinden, wie Schriftstellerinnen in der DDR feministisches Bewusstsein artikuliert haben, d.h. feministisches Bewusstsein unter den vom Staatssozialismus geschaffenen Bedingungen.From the 1960s on, women writers in the German Democratic Republic (GDR, including Christa Wolf, Irmtraud Morgner, Sarah Kirsch, Brigitte Reimann, Charlotte Worgitzky, Lia Pirskawetz, and Maya Wiens, produced a large body of writing on women’s issues. Martens wants to investigate how these women authors in the GDR have articulated their feminist consciousness under the conditions of state socialism. Martens’ use of the title The Promised Land is an allusion to a book by Irmtraud Morgner, an author whom, along with Christa Wolf, Martens considers one of the most important witnesses of feminist writing in the GDR. In Morgner’s book The Life and Adventures of Troubadour Beatriz the term “promised land” is being

  6. Value of breast MRI as supplement to mammography and sonography for high risk breast cancer patients; Wertigkeit der Mamma-MRT als Ergaenzung zu Mammographie und Sonographie bei Patientinnen mit erhoehtem Mammakarzinomrisiko

    Energy Technology Data Exchange (ETDEWEB)

    Schlossbauer, T.; Hellerhoff, K.; Reiser, M. [Klinikum Grosshadern der Ludwig-Maximilians-Universitaet Muenchen, Institut fuer Klinische Radiologie, Muenchen (Germany)

    2008-04-15

    The aim of this study is to give an overview on early detection of breast cancer in patients with an increased risk of breast cancer. Sensitivities and diagnostic accuracies of breast MRI, mammography and ultrasound were compared. A systematic literature search of the past 3 years was performed. Studies which compared breast imaging modalities and used image-guided biopsy results as standard of reference were included. Patients included had to have had an increased lifetime risk for breast cancer (>15%). Regarding sensitivity and diagnostic accuracy, breast MRI performed best in comparison to the other modalities within this collective of patients. Sensitivities ranged from 71-100%, 0-78%, and 13-65%, for MRI, mammography, and ultrasound, respectively Breast MRI is a well established tool for screening in patients at high risk for developing breast cancer and is a valuable supplement to mammography and ultrasound within this selected cohort of patients. (orig.) [German] Ziele der Arbeit sind die inhaltliche Einfuehrung in das Thema Frueherkennung des Mammakarzinoms bei Patientinnen mit erhoehtem Risiko und eine systematische Analyse der Wertigkeit von MRT und anderen bildgebenden Verfahren in diesem Zusammenhang. Es wurde eine systematische Literaturrecherche ueber die letzten 3 Jahre durchgefuehrt. Dabei wurden Vergleichsstudien der verschiedenen bildgebenden Verfahren in der Mammadiagnostik beruecksichtigt, bei denen die bildgesteuerte Biopsie als Goldstandard angegeben wurde. Von allen bildgebenden Verfahren zeigt die Mamma-MRT bei Patientinnen mit familiaerem Risiko die hoechste Sensitivitaet und diagnostische Genauigkeit bei der Detektion des Mammakarzinoms. Fuer MRT, Mammographie und Sonographie werden Sensitivitaeten zwischen 71 und 100%, 0 und 78% sowie 13 und 65% angegeben. Die Mamma-MRT ist ein etabliertes Verfahren zum Screening von Risikopatientinnen. Uebereinstimmend wird der diagnostische Nutzen der Mamma-MRT als ergaenzendes Verfahren zu Mammographie

  7. Hybrid entanglement concentration assisted with single coherent state

    International Nuclear Information System (INIS)

    Guo Rui; Zhou Lan; Sheng Yu-Bo; Gu Shi-Pu; Wang Xing-Fu

    2016-01-01

    Hybrid entangled state (HES) is a new type of entanglement, which combines the advantages of an entangled polarization state and an entangled coherent state. HES is widely discussed in the applications of quantum communication and computation. In this paper, we propose three entanglement concentration protocols (ECPs) for Bell-type HES, W-type HES, and cluster-type HES, respectively. After performing these ECPs, we can obtain the maximally entangled HES with some success probability. All the ECPs exploit the single coherent state to complete the concentration. These protocols are based on the linear optics, which are feasible in future experiments. (paper)

  8. Entanglement-assisted quantum MDS codes constructed from negacyclic codes

    Science.gov (United States)

    Chen, Jianzhang; Huang, Yuanyuan; Feng, Chunhui; Chen, Riqing

    2017-12-01

    Recently, entanglement-assisted quantum codes have been constructed from cyclic codes by some scholars. However, how to determine the number of shared pairs required to construct entanglement-assisted quantum codes is not an easy work. In this paper, we propose a decomposition of the defining set of negacyclic codes. Based on this method, four families of entanglement-assisted quantum codes constructed in this paper satisfy the entanglement-assisted quantum Singleton bound, where the minimum distance satisfies q+1 ≤ d≤ n+2/2. Furthermore, we construct two families of entanglement-assisted quantum codes with maximal entanglement.

  9. Dynamics of Quantum Entanglement in Reservoir with Memory Effects

    International Nuclear Information System (INIS)

    Hao Xiang; Sha Jinqiao; Sun Jian; Zhu Shiqun

    2012-01-01

    The non-Markovian dynamics of quantum entanglement is studied by the Shabani-Lidar master equation when one of entangled quantum systems is coupled to a local reservoir with memory effects. The completely positive reduced dynamical map can be constructed in the Kraus representation. Quantum entanglement decays more slowly in the non-Markovian environment. The decoherence time for quantum entanglement can be markedly increased with the change of the memory kernel. It is found out that the entanglement sudden death between quantum systems and entanglement sudden birth between the system and reservoir occur at different instants. (general)

  10. Quantum Entanglement in Neural Network States

    Directory of Open Access Journals (Sweden)

    Dong-Ling Deng

    2017-05-01

    Full Text Available Machine learning, one of today’s most rapidly growing interdisciplinary fields, promises an unprecedented perspective for solving intricate quantum many-body problems. Understanding the physical aspects of the representative artificial neural-network states has recently become highly desirable in the applications of machine-learning techniques to quantum many-body physics. In this paper, we explore the data structures that encode the physical features in the network states by studying the quantum entanglement properties, with a focus on the restricted-Boltzmann-machine (RBM architecture. We prove that the entanglement entropy of all short-range RBM states satisfies an area law for arbitrary dimensions and bipartition geometry. For long-range RBM states, we show by using an exact construction that such states could exhibit volume-law entanglement, implying a notable capability of RBM in representing quantum states with massive entanglement. Strikingly, the neural-network representation for these states is remarkably efficient, in the sense that the number of nonzero parameters scales only linearly with the system size. We further examine the entanglement properties of generic RBM states by randomly sampling the weight parameters of the RBM. We find that their averaged entanglement entropy obeys volume-law scaling, and the meantime strongly deviates from the Page entropy of the completely random pure states. We show that their entanglement spectrum has no universal part associated with random matrix theory and bears a Poisson-type level statistics. Using reinforcement learning, we demonstrate that RBM is capable of finding the ground state (with power-law entanglement of a model Hamiltonian with a long-range interaction. In addition, we show, through a concrete example of the one-dimensional symmetry-protected topological cluster states, that the RBM representation may also be used as a tool to analytically compute the entanglement spectrum. Our

  11. Detecting faked continuous-variable entanglement using one-sided device-independent entanglement witnesses

    Science.gov (United States)

    Opanchuk, B.; Arnaud, L.; Reid, M. D.

    2014-06-01

    We demonstrate the principle of one-sided device-independent continuous-variable (CV) quantum information. In situations of no trust, we show by enactment how the use of standard CV entanglement criteria can mislead Charlie into thinking that Alice and Bob share entanglement, when the data are actually generated classically using a local-hidden-variable theory based on the Wigner function. We distinguish between criteria that demonstrate CV entanglement, and criteria that demonstrate the CV Einstein-Podolsky-Rosen (EPR) steering paradox. We show that the latter, but not the former, are necessarily one-sided device-independent entanglement witnesses, and can be used by Charlie to signify genuine EPR entanglement, if he trusts only Alice. A monogamy result for the EPR steering paradox confirms the security of the shared amplitude values in that case.

  12. Efficient multipartite entanglement purification with the entanglement link from a subspace

    Energy Technology Data Exchange (ETDEWEB)

    Deng Fuguo [Department of Physics, Applied Optics Beijing Area Major Laboratory, Beijing Conventional University, Beijing 100875 (China)

    2011-11-15

    We present an efficient multipartite entanglement purification protocol (MEPP) for N-photon systems in a Greenberger-Horne-Zeilinger state with parity-check detectors. It contains two parts. One is the conventional MEPP with which the parties can obtain a high-fidelity N-photon ensemble directly, similar to the MEPP with controlled-not gates. The other is our recycling MEPP in which the entanglement link is used to produce some N-photon entangled systems from entangled N{sup '}-photon subsystems (2{<=}N{sup '}entangled N{sup '}-photon subsystems are obtained efficiently by measuring the photons with potential bit-flip errors. With these two parts, the present MEPP has a higher efficiency than all other conventional MEPPs.

  13. Scheme for entanglement concentration of unknown atomic entangled states by interference of polarized photons

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hong-Fu; Zhu, Ai-Dong; Zhang, Shou [Department of Physics, College of Science, Yanbian University, Yanji, Jilin 133002 (China); Yeon, Kyu-Hwang, E-mail: hfwang@ybu.edu.c, E-mail: szhang@ybu.edu.c [Department of Physics and BK21 Program for Device Physics, College of Natural Science, Chungbuk National University, Cheongju, Chungbuk 361-763 (Korea, Republic of)

    2010-12-14

    Based on the interference effect of polarized photons, we propose a practical scheme for entanglement concentration of unknown atomic entangled states. In the scheme, two {lambda}{lambda}-type atoms belonging to different entangled pairs are individually trapped in two spatially separated cavities. By the subsequent detection of the polarized photons leaking out of the separate optical cavities, Alice and Bob as two distant parties can probabilistically extract one maximally entangled four-atom Greenberger-Horne-Zeilinger (GHZ) state from two identical partially entangled Einstein-Podolsky-Rosen (EPR) pairs. We also discuss the influence of cavity decay on the success probability of the scheme. The scheme is feasible and within the reach of current experimental technology.

  14. Thyroid volume reduction following radioiodine therapy in patients with autonomous goitre and Graves` disease; Volumenreduktion der Schilddruese nach Radiojodtherapie bei Patienten mit Schilddruesenautonomie und Morbus Basedow

    Energy Technology Data Exchange (ETDEWEB)

    Dederichs, B. [Klinik und Poliklinik fuer Nuklearmedizin, Univ. Koeln (Germany); Otte, R. [Klinik und Poliklinik fuer Nuklearmedizin, Univ. Koeln (Germany); Klink, J.E. [Klinik und Poliklinik fuer Nuklearmedizin, Univ. Koeln (Germany); Schicha, H. [Klinik und Poliklinik fuer Nuklearmedizin, Univ. Koeln (Germany)

    1996-10-01

    Wochen bis 3 Monate nach RJTh nachweisbar. Schlussfolgerung: Diese Beobachtungen legen den Schluss nahe, dass die thyreoidale Grunderkrankung den therapeutischen Effekt der RJTh beeinflusst. Dies koennte teilweise durch die vollstaendige Suppression des nichtautonomen Gewebes waehrend der RJTh erklaert werden. Fuer die Patienten mit UFA, die im Vergleich zu Patienten mit MFA eine ca. 1,7fach hoehere Herddosis erhalten hatten, fiel die SVR um den Faktor 1,6 staerker aus. Dies belegt einen direkten Zusammenhang zwischen der effektiven Herddosis und dem Ausmass der SVR nach RJTh. (orig.)

  15. Die Rolle der Finite-Elemente-Berechnung in der Produktentwicklung

    Science.gov (United States)

    Esteban, Ignacio

    Der Preisdruck wird in allen Industriebranchen immer größer. Aufgrund der Qualitätsstandards gewinnt der Entwicklungsprozess immer mehr an Bedeutung, so dass die Produktkosten durch diese Phase erheblich beeinflusst werden. Die Anwendung computergestützter Konstruktion und Berechnung hat sich als effektives Entwicklungswerkzeug erwiesen, um kürzere Entwicklungszeiten und eine höhere Qualität zu erreichen. Dadurch tragen diese virtuellen Werkzeuge zu niedrigeren Produktkosten bei. Dieser Artikel orientiert sich am Potential der Finite-Elemente (FE)-Berechnung im Entwicklungsprozess. Eine der neuesten Anwendungsmöglichkeiten der FE-Simulation wird am Beispiel einer Werkzeugmaschine präsentiert. In diesem Beispiel wird die Maschinensteuerung in das FE-Modell implementiert, und ein Beschleunigungsvorgang wird simuliert.

  16. Becomings: Narrative Entanglements and Microsociology

    Directory of Open Access Journals (Sweden)

    Maria Tamboukou

    2015-01-01

    Full Text Available In this article, I look back in an art/research experiment of convening an exhibition of women artists and inviting them to a round-table discussion in the context of a sociological conference. The artists who took part in this event had been previously interviewed for a feminist research project, entitled "In the Fold Between Life and Art, a Genealogy of Women Artists". The conference exhibition gave the artists the opportunity to appear to an academic audience and present their work while the round-table discussion created a forum for a narrative event where all women were invited to recount stories of becoming an artist. In looking at this event I want to explore questions around the possibilities and limitations of narratives in microsociological inquiries. In following trails of ARENDT's theorisation of stories, I explore connections and tensions between social, political and cultural entanglements in narrative research. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1501193

  17. Das Smart Meter Gateway - Der kritische Erfolgsfaktor für die Digitalisierung der Energiewende

    Science.gov (United States)

    Abs, Paul-Vincent

    Der kritische Erfolgsfaktor der Digitalisierung in der Energiewirtschaft liegt im bevorstehenden hohen Investitionsvolumen und der Beherrschung der neuen Technik. Ein Weg zur Kostenminimierung liegt im Zusammenschluss der einzelnen Akteure, um gemeinsame Skalenvorteile zu heben. Auch bieten neue Geschäftsmodelle die Möglichkeit, zusätzliche Erlöse zu generieren.

  18. Grundlagen der zeichnerischen Darstellung

    Science.gov (United States)

    Döring, Peter

    Eine Technische Zeichnung muss nach DIN 6774 Teil 1 in der Weise angefertigt werden, dass sie übersichtlich, unmissverständlich, auch in verkleinertem Maßstab lesbar bleibt, kostengünstig reproduzierbar und dauerhaft archivierbar ist. Zu dem Zweck benötigt man entsprechendes Papier und angepasstes Zeichengerät. Heute ist die Anfertigung mit entsprechenden Rechnerprogrammen möglich.

  19. Influence of parameters entanglement on the quantum algorithms

    Directory of Open Access Journals (Sweden)

    Alexey V. Kasarkin

    2012-05-01

    Full Text Available The article we consider the influence of parameters entanglement on the quantum algorithms, in particular influence of partial entanglement for quantum teleportation. The simulation results presented in chart form.

  20. Entanglement dynamics of a pure bipartite system in dissipative environments

    Energy Technology Data Exchange (ETDEWEB)

    Tahira, Rabia; Ikram, Manzoor; Azim, Tasnim; Suhail Zubairy, M [Centre for Quantum Physics, COMSATS Institute of Information Technology, Islamabad (Pakistan)

    2008-10-28

    We investigate the phenomenon of sudden death of entanglement in a bipartite system subjected to dissipative environments with arbitrary initial pure entangled state between two atoms. We find that in a vacuum reservoir the presence of the state where both atoms are in excited states is a necessary condition for the sudden death of entanglement. Otherwise entanglement remains for an infinite time and decays asymptotically with the decay of individual qubits. For pure 2-qubit entangled states in a thermal environment, we observe that the sudden death of entanglement always happens. The sudden death time of the entangled states is related to the temperature of the reservoir and the initial preparation of the entangled states.