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

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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

Typologische Aufgaben der historischen Textlinguistik

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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

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

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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.

Die Gewalt der Frauen The aggression of women

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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.

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.

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.

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

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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.

Der Einfluss von rechtsgerichtetem Autoritarismus und sozialer Dominanzorientierung auf homophobe Einstellungen

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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.

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

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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.

Medienbildung in der Volksschule

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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

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...

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

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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.

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

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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.

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

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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.

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...

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

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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.

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

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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.

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

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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.

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...

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)

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

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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.

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

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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.

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)

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.

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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.

Geschichtlicher Überblick

Science.gov (United States)

Bölke, Klaus-Peter

Die Nachweise einer schadlosen Ableitung von Abwässern lassen sich bis weit in die Vergangenheit zurückverfolgen. Sie waren bereits zur damaligen Zeit eine Forderung zur Pflege der öffentlichen Reinlichkeit. Der Kanalisationsbau ist auch immer ein Ausdruck der Kultur eines Volkes gewesen. So kann festgestellt werden, dass im Zusammenhang mit der Hochkultur eines Volkes auch der Kanalbau ein vorherrschendes Thema war. Der Kanalbau steht auch in einem engen Zusammenhang mit dem Wasserleitungsbau. Es ist nur logisch, dass dort wo Wasser teilweise aus großer Entfernung herangeführt worden ist, dieses dann nach Gebrauch auch wieder schadlos beseitigt werden musste.

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.)

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

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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

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.

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

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.)

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

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

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.

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.)

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.)

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.

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)

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

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- ...

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.)

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

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

Entsorgungswirtschaft zwischen Grünem Punkt und Dosenpfand

OpenAIRE

Johann Wackerbauer

2003-01-01

Die Zeiten der hohen Wachstumsraten in der Abfallentsorgung dürften vorbei sein. Die Nachfrage nach Entsorgungsleistungen wird stärker von der Umweltpolitik als von der allgemeinen Konjunkturentwicklung beeinflusst. Die Turbulenzen im Zusammenhang mit der Einführung der Pfandpflicht auf Einweggetränkeverpackungen und die Diskussion um die Monopolstellung der Gesellschaft »Der Grüne Punkt - Duales System Deutschland AG« im Bereich der Entsorgung von Verkaufsverpackungen haben die Entsorgungs...

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

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.)

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.

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.

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.)

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

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.

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

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 ...

Leitung und Kooperation in wissenschaftlichen Bibliotheken Berlins - eine empirische Untersuchung

OpenAIRE

Paul, Gerhard

1998-01-01

Die vorliegende Arbeit greift ein im bibliotheks- und IuK-wissenschaftlichen sowie im fachprofessionellen Diskurs bisher weitgehend vernachlässigtes, aber immer bedeutsameres Thema auf: das vertikale soziale Geschehen in der Arbeitsorganisation ?wissenschaftliche Bibliothek". Die Absicht der Untersuchung lag darin, einen Zusammenhang zwischen dem Interaktionsverhalten der Leitungspersonen einerseits und der Mobilisierung von Leistungs- und Innovationspotentialen bei den Mitarbeiterinnen und M...

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)

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.

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

Die Entstehung einer Nachbarsegmentdekompensation nach lumbaler Spondylodese. Einfluß des sagitalen Profils

OpenAIRE

Noe, Stephan

2003-01-01

Die vorliegende Arbeit beschäftigt sich mit der Frage, ob ein Zusammenhang zwischen der frühen Dekompensation einer Nachbaretage neben einem fusioniertem Bandscheibensegment im Lendenwirbelsäulenbereich und dem sagittalen Profil der Lendenwirbelsäule besteht. Im Rahmen der Untersuchungen wurden in einer retrospektiven Untersuchung die Krankenakten und Röntgenbilder von 51 Patienten der Zentralkliniken Bad Berka (Wirbelsäulenchirurgie) und Patienten der Orthopädischen Klinik des Universitä...

Generation Y: Arbeitsbezogene Erwartungen und affektives Commitment

OpenAIRE

Giry, Nathalie

2016-01-01

Die Erwartungen der Generation Y zu kennen, ist wichtig für Unternehmen, die Leistungsträger aus dieser Generation langfristig binden wollen. Die affektive Bindung der Generation Y gegenüber einer Organisation, der Zusammenhang zwischen der Erfüllung arbeitsbezogener Erwartungen und affektivem Commitment sowie der Fluktuationsneigung der Generation Y werden empirisch überprüft. Die Generation Y hat hohe Erwartungen an Unternehmenswerte und Unternehmenskultur. Es wurden Zusammenhänge zwischen ...

Energieversorgung in Friedrichshafen in ihrem ökonomischen, technischen und ikonographischen Umfeld

OpenAIRE

Leu, Ulrike

2005-01-01

In der vorliegenden Arbeit geht es um die Entwicklung der Stromversorgung in Friedrichshafen. Die Energieversorgungsgeschichte dieser Stadt ist besonders interessant, da sie mit der Stadtgeschichte in außerordentlich engem Zusammenhang steht.Dabei soll insbesondere untersucht werden, inwiefern die Stromversorgung im Bezug zu den Industriebetrieben der Stadt steht, die sich aus der Zeppelinforschung entwickelt haben, da die Zeppelinindustrie durch die beiden Weltkriege einen enorm großen Aufsc...

The P2-Cottbus test and demonstration project; Versuchs- und Demonstrationsbauvorhaben P2-Cottbus

Energy Technology Data Exchange (ETDEWEB)

Fuerst, W. [Institut fuer Erhaltung und Modernisierung von Bauwerken e.V., Berlin (Germany); Braeunig, K.U. [Technische Univ. Dresden (Germany)

1997-12-31

The paper is a compilation of the essential results, experiences and problems encountered during the finalized first measuring period with the following measurements: measurements in order to establish the actual condition of the building prior to its modernization, control measurements in connection with the start of operation and adjustment of the building`s heating and ventilation system, and measurements for the valuation of energy conservation measures. Further, some results of measurements from the current, second, measurement period are reported. All measuring results are to be considered as preliminary, as the project will not be finalized before 31 December 1997. (MSK) [Deutsch] Der Beitrag enthaelt eine Zusammenstellung wesentlicher Ergebnisse, Erfahrungen und Probleme aus der abgeschlossenen ersten Messperiode mit folgenden Messungen: Messungen im Zusammenhang mit der Analyse des Istzustandes vom Versuchsgebaeude vor der Sanierung, Kontrollmessungen im Zusammenhang mit der Inbetriebnahme und Einregulierung der Heizung und Lftung des Gebaeudes sowie Messungen zur Untersuchung und Bewertung der energetischen Sanierungsnahmen. Ausserdem sind Ergebnisse der z.Z. laufenden zweiten Messperiode enthalten. Alle Ergebnisse sind mit dem Attribut ``vorlaeufig`` versehen, da das Projekt fruehestens am 31.12.97 abgeschlossen sein wird.

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.)

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.)

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.)

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

Narrative Expositionstherapie (NET) für Menschen nach Gewalt und Flucht : Ein Einblick in das Verfahren

OpenAIRE

Schauer, Maggie; Elbert, Thomas; Neuner, Frank

2017-01-01

Die Narrative Expositionstherapie (NET) ist ein effizientes Kernelement der Behandlung von Kindern und Erwachsenen, die unter den Folgen von Mehrfach- und Komplextraumatisierung nach Gewalt und Flucht leiden. Die chronologische Erarbeitung einer Narration, der individuellen Lebensgeschichte in der NET ermöglicht Traumaüberlebenden eine Gesamtschau ihres Lebens und so die Integration der Lebenserfahrungen in den biografischen Zusammenhang. Sie aktiviert Ressourcen und erlaubt korrigierende Bez...

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.)

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

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.

Persönlichkeit und Belastungs- bzw. Ressourcenfaktoren. Eine multivariate Betrachtung

OpenAIRE

Schneider, Benno

1997-01-01

In verschiedenen Modellvorstellungen wird der Zusammenhang zwischen Persönlichkeitseigenschaften und subjektiv erlebtem Streß immer wieder postuliert. Die Forschung ging dabei immer nur einzelnen Variablen nach. Diese Arbeit untersucht den Zusammenhang zwischen einer mehrdimensional erhobenen Persönlichkeit und die mit einem Screeningverfahren erfaßten belastende Ereignisse, soziale Unterstützung und objektiv erlebte positiven oder negative Lebensereignisse. Es wurden über 420 Patienten aus A...

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

Ausländische Direktinvestitionen und Technologietransfer im angolanischen Energiesektor

Directory of Open Access Journals (Sweden)

2016-04-01

Full Text Available Dem Zusammenhang von ausländischen Direktinvestionen (Foreign Direct Investment, FDI und Technologietransfer wird sowohl in der Forschung als auch in der politischen Analyse große Bedeutung zugeschrieben. Zahlreiche Veröffentlichungen belegen, dass FDI den Transfer von und/oder den Zugang zu Technologien erleichtert. Allerdings gibt es zu wenige empirische Studien, die diesen Zusammenhang in Bezug auf die Wirtschaft afrikanischer Staaten untersuchen. Der Autor will diese Lücke zu einem kleinen Teil schließen, indem er die Bedeutung des Technologietransfers durch den Zufluss von FDI im Energiesektor Angolas ermittelt. Seine Analyse basiert auf qualitativer Forschung in Angola im Jahr 2014. Er zeigt auf, dass sich die Erzeugung von Energie(trägern und die Verteilungsinfrastruktur - maschinelle Ausrüstung und Qualifizierung - durch den Zufluss von FDI erheblich entwickeln konnte. Allerdings gebe es keinen Beleg dafür, dass dieser Zufluss die endogenen wissenschaftlichen und technologischen Forschungspotenziale im angolanischen Energiesektor gefördert hat. Der Autor empfiehlt politische Maßnahmen zur Förderung dieser Fähigkeiten, insbesondere im Bereich der Produktion.

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.

Person, Profil, Privatheit. Die Suche nach Eigennamen als informationsethisches Problem

OpenAIRE

Bordat, Josef

2005-01-01

Zusammenfassung: Der Schutz der Privatsphäre im Rahmen der Nutzung von Internet-Suchmaschinen wird auf der Ebene der privacy als Recht auf wirksamen Schutz seiner Daten und der Privatheit als Recht des "Für-Sich-Seins", auf "solitude, anonymity and intimacy" sowie auf "control of personal information" untersucht. Gerade letztere gerät im Zusammenhang mit der Suche nach Eigennamen in Gefahr, da im Ergebnis über persönliche Daten verfügt wird, ohne das die betreffende Person weiß, wer zu wel...

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.)

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.

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.

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

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...

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...

Ein überfälliger Dialog. Wie Frauen- und Geschlechterforschung und Soziologie miteinander ins Gespräch kommen können

Directory of Open Access Journals (Sweden)

Heike Kahlert

2007-03-01

Full Text Available Die Monographie von Brigitte Aulenbacher zum Zusammenhang von Rationalisierung, Geschlecht und Gesellschaft ist in gegenstandsbezogener und methodologischer Hinsicht ambitioniert, überzeugend und lesenswert. Die Studie stellt eine solide, manchmal auch etwas zu weitschweifige und detailreiche Grundlage für weiterführende Diskussionen zwischen der (sozialwissenschaftlichen Frauen- und Geschlechterforschung und der Soziologie, genauer der Gesellschaftstheorie in zeitdiagnostischer Perspektive, Arbeits-, Industrie-, Organisations- und Techniksoziologie, dar.

Informationskompetenz und Information Literacy

OpenAIRE

Ingold, Marianne

2012-01-01

Informationskompetenz ist heute als Begriff , Konzept und praktisches Tätigkeitsfeld von Bibliotheken weltweit etabliert. Entstehung, Verbreitung und Entwicklung von „Informationskompetenz“ im deutschsprachigen Raum stehen in engem Zusammenhang mit dem in den USA und international seit den 1980er Jahren diskutierten und praktisch umgesetzten Konzept der „Information Literacy“. Auch wenn die beiden Begriffe in der Regel gleichbedeutend verwendet werden, zeigt ein Vergleich der vorwiegend aus e...

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

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.

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.

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.

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

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

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.

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.

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.)

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.)

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.)

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

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)

Toxicology of ozone on the basis of animal and clinical experimental studies; Toxikologie von Ozon auf der Grundlage tier- und klinisch-experimenteller Untersuchungen

Energy Technology Data Exchange (ETDEWEB)

Kappus, H. [Humboldt-Universitaet, Berlin (Germany). Virchow-Klinikum

2000-07-01

This synopsis focuses on the toxic effects of ozone in humans and animals following inhalation. It is limited to studies that deal exclusively with ozone. These studies are reviewed with respect to action mechanisms underlying ozone-specific toxicity and, where present, dose-effect relationships. Both aspects today are indispensable for any risk assessment. As there have been very many studies on this issue and the number of publications increases every year, the present paper only quotes a few review articles and does not mention original papers unless they are of recent date or offer new information. [German] Diese Uebersicht konzentriert sich auf die toxischen Effekte von Ozon nach Inhalation bei Mensch und Tier. Nur Untersuchungen mit Ozon alleine werden miteinbezogen. Sie werden hauptsaechlich im Zusammenhang mit dem Wirkungsmechanismus der Ozon-bedingten Toxizitaet und, soweit vorhanden, Konzentrations-Wirkungsbeziehungen behandelt. Beide Aspekte sind heute fuer eine Risikoabschaetzung unerlaesslich. Da sehr viele Untersuchungen vorliegen und die Zahl der Veroeffentlichungen jaehrlich ansteigt, sollen hier nur einige neuere Uebersichtsarbeiten zitiert werden und Originalarbeiten nur dann erwaehnt werden, wenn sie neueren Datums sind bzw. zusaetzliche Informationen bringen. (orig.)

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

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.)

Demands on digital automation; Anforderungen an die Digitale Automation

Energy Technology Data Exchange (ETDEWEB)

Bieler, P.

1995-12-31

In chapter 12 of the anthology about building control the demands on digital automation are presented. The following aspects are discussed: variety of the companies` philosophies, demands of the customer/investor, demands of the use of buildings/rooms, the user, point of view of manufacturer of technical plants. (BWI) [Deutsch] Kapitel 12 des Sammelbandes ueber Building Control stellt die Anforderungen an die Digitale Automation vor. In diesem Zusammenhang wird auf folgende Themenbereiche eingegangen: Spektrum der Firmenphilosophien, Forderungen der Auftraggeber/Investoren, der Gebaeude-/Raumnutzung, der Betreiber sowie Sicht der Ersteller betriebstechnischer Anlagen. (BWI)

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 ...

EU-Verordnung zu "Konfliktmineralien": Ein Schritt zu höherer Rechenschaftspflicht im Rohstoffsektor?

OpenAIRE

Küblböck, Karin; Grohs, Hannes

2017-01-01

"No blood in my cell phone" - Anfang der 2000er-Jahre zeigten Kampagnen von Nichtregierungsorganisationen (NGOs) Verbindungen zwischen Rohstoffen in Elektronikprodukten und der Finanzierung des Krieges in der Demokratischen Republik Kongo (DRC) auf. In diesem Zusammenhang rückte auch die Verantwortung von Unternehmen für die Gestaltung ihrer Lieferkette verstärkt ins öffentliche Bewusstsein. 2017 tritt nun eine EU-Verordnung in Kraft, die verhindern soll, dass Unternehmen durch ihre Rohstoffb...

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

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)

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.)

Jeopardy alarm system - a building technology like any other technology?; Gefahrenmeldetechnik - eine Gebaeudetechnik wie jede andere?

Energy Technology Data Exchange (ETDEWEB)

Hegewald, B. [ZVEI, Fachkreis Ueberfall- und Einbruchmeldeanlagen, Frankfurt am Main (Germany)]|[Siemens AG, Muenchen

1995-12-31

In chapter 15 of the anthology about building control the jeopardy alarm system technology is described. The following aspects are discussed: importance of the safety, definition of jeopardy alarm systems, application of safety technique, instructions, guidelines and regulations, advantages of safety systems, integration or combination. (BWI) [Deutsch] Kapitel 15 des Sammelbandes ueber Buidling Control ist der Gefahrenmeldetechnik gewidmet. In diesem Zusammenhang wird auf folgende Themenbereiche eingegangen: Stellenwert der Sicherheit; Definition der Gefahrenmeldeanlagen; Einsatz der Sicherungstechnik; Vorschriften, Richtlinien und Bestimmung; Vorteile von Sicherungssystemen; Integration oder Kombination. (BWI)

Neue Energiespeichermaterialien für Lithium-Schwefel-Batterien

OpenAIRE

Frey, Martin

2017-01-01

Angesichts schwindender Mengen sowie hoher Preise fossiler Energieträger und der damit einhergehenden Umweltbelastung erscheint ein Umstieg auf regenerative Energiequellen unausweichlich. Die stark schwankenden Leistungen aus Wind- und Sonnenenergie generieren dabei einen starken Bedarf im Bereich der elektrochemischen Energiespeicher. Die Lithium-Schwefel Technologie repräsentiert in diesem Zusammenhang einen vielversprechenden Kandidaten einer neuen Generation leistungsfähiger, sicherer, ab...

Untersuchungen zum Fettsäurestoffwechsel bei koronarer Herzkrankheit

OpenAIRE

Richter, Wolf-Stefan

2001-01-01

Die nicht-invasive bildgebende Diagnostik hat bei koronarer Herzkrankheit einen wichtigen Stellenwert für die Diagnosestellung und Therapieplanung. In diesem Zusammenhang liefern nuklearmedizinische Verfahren wichtige Daten zur Gewebsperfusion und erlauben die bildliche Darstellung und Quantifizierung relevanter Details des kardiomyozytären Stoffwechsels. Die quantitativ bedeutendste Methode der nuklearmedizinischen Herzdiagnostik ist die Perfusionsszintigraphie mit Tl-201 oder einem der Tc-9...

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.

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

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

Positive Effekte des Mindestlohns auf Arbeitsplatzqualität und Arbeitszufriedenheit

OpenAIRE

Pusch, Toralf; Rehm, Miriam

2017-01-01

Über den Zusammenhang zwischen Mindestlöhnen und Änderungen bei der Arbeitsplatzqualität ist bisher wenig bekannt. Nach der Mindestlohneinführung in Deutschland stieg die Arbeitsplatzzufriedenheit insgesamt. Neben höheren Stunden- und Bruttolöhnen und verringerten Arbeitszeiten gibt es als möglichen Grund auch eine arbeitsorganisatorische Aufwertung der Arbeitsplätze. Bei bestehenden Beschäftigungsverhältnissen konnten Hinweise auf Verbesserungen beim Betriebsklima und einer mehr auf Mitarbei...

"Challenge-led"-Innovation in China - das Beispiel Elektromobilität

OpenAIRE

Fan, Cheng; Reiß, Thomas; Thielmann, Axel

2014-01-01

[Einleitung] Nach mehrjährigen Diskussionen über politische Maßnahmen zum Umweltschutz und zur Nachhaltigkeit sowie im Zusammenhang mit der globalen Finanzkrise, haben eine Reihe von Regierungen weltweit, wie z.B. die USA, Japan, China, Deutschland und Frankreich, seit 2009 erneut Initiativen ergriffen und ihre nationalen Zielwerte für die Markteinführung und -diffusion von Elektrofahrzeugen (EV) angekündigt. Der Grund liegt darin, dass Investitionen in "Green Technologies" auf der einen Seit...

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.

Führung und Machiavellismus

NARCIS (Netherlands)

Belschak, F.D.; den Hartog, D.N.; Felfe, J.

2015-01-01

In diesem Beitrag wird der Zusammenhang zwischen Führung und Machiavellismus aus zwei verschiedenen Perspektiven betrachtet. Zum einen werden neuere Forschungsergebnisse referiert, wie machiavellistische Mitarbeiter auf verschiedene Führungsstile ihres Vorgestzten reagieren und so mit Hinblick auf

Energy as a technology: Thermodynamics, energy engineering, environment, renewable energy, rational energy use. 2. rev. ed.; Technologie Energie: Thermodynamik, Energietechnik, Umwelt, regenerative Energien, rationeller Energieeinsatz

Energy Technology Data Exchange (ETDEWEB)

Schuberth, R.

2000-07-01

The book discusses the technical and scientific fundamentals and the ecological consequences of anthropogenic energy conversion. The information is to make the public energy discussion more rational and less emotional. [German] Trotz oder gerade wegen der duesteren Zukunftsaussichten sind sachliche und fundierte Informationen ueber die Zusammenhaenge zu diesem Thema erforderlich. In diesem Buch werden schwerpunktmaessig die technisch-naturwissenschaftlichen Sachverhalte und die oekologischen Folgeerscheinungen, die im Zusammenhang mit der anthropogenen Energieumwandlung auftreten, dagestellt. Diese Kenntnisse sollten auch zu einer Versachlichung der Energiediskussion und einer rationaleren Beurteilung der Situation fuehren koennen. (orig.)

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.

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

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.

I distrust self-declared patent solutions. Interview with Dr. Angela Merkel, Federal Minister of the Environment; Mich stoeren vermeintliche Patentrezepte. Interview mit Bundesumweltministerin Dr. Angela Merkel

Energy Technology Data Exchange (ETDEWEB)

Merkel, A. [Bundesministerium fuer Umwelt, Naturschutz und Reaktorsicherheit, Bonn (Germany); Roehrlich, D.

1995-12-31

Dr. Merkel answered questions on energy supply and environmental protection. The following subjects were discussed: Efficient use of energy, legal regulations, energy mix, developments in nuclear technology, better acceptance of renewable energy sources, nuclear phase-out - not a feasible alternative, increasing acceptance of waste incineration plants. (BWI) [Deutsch] Der vorliegende Beitrag gibt ein Interview mit der Bundesumweltministerin Merkel zu Fragen der Energieversorgung und des Umweltschutzes wider. In diesem Zusammenhang werden folgende Themenbereiche diskutiert: Effizientere Energienutzung, rechtliche Regelungen, Zusammensetzung der eingesetzten Energietraeger, Weiterentwicklung der Kerntechnologie, Abbau von Hemmnissen bei erneuerbaren Energiequellen, Verzicht auf Kernkraft nicht sinnvoll, zunehmende Akzeptanz fuer Muellverbrennungsanlagen. (BWI)

Building automation - synthesis of the past and present; Gebaeudeautomation - Synthese aus Vergangenheit und Zukunft

Energy Technology Data Exchange (ETDEWEB)

Fassbender, H.W. [Honeywell AG, Maintal (Germany)

1995-12-31

In chapter 13 of the anthology about building control the historical development in the field of building automation is described. The following aspects are discussed: The development from central process control technique for buildings to building automation, synthesis of DDC-technique and process control technique, technology of the automation and management level. (BWI) [Deutsch] Kapitel 13 des Sammelbandes ueber Building Control ist dem Thema der geschichtlichen Entwicklung der Gebaeudeautomation gewidmet. In diesem Zusammenhang wird auf folgende Themen eingegangen: Von der ZLT-G zur Gebaeudeautomation; Gebaeudeautomation, die Synthese von DDC und Leittechnik; Technologien der Automationsebene sowie der Managementebene. (BWI)

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.)

Transformation

OpenAIRE

Laux, Gunther

2007-01-01

Die Arbeit befasst sich mit der These, dass jegliche technologische Entwicklung ihre Widerspiegelung in Gesellschaft, Wirtschaft und Stadt findet. In diesem Zusammenhang wird untersucht ob, wodurch, inwieweit oder warum eine Veränderung des europäischen Stadtbildes und des Raumbegriffs aufgrund der aktuellen Medientechnologie stattfindet. Vor dem Hintergrund situativer, phänomenologischer, historischer, soziologischer, regulativer und ökonomischer Betrachtungen bildet die Entwicklung einer al...

Holographic Van der Waals-like phase transition in the Gauss–Bonnet gravity

Energy Technology Data Exchange (ETDEWEB)

He, Song, E-mail: hesong17@gmail.com [Max Planck Institute for Gravitational Physics (Albert Einstein Institute), Am Mühlenberg 1, 14476 Golm (Germany); State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China); Li, Li-Fang, E-mail: lilf@itp.ac.cn [Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing 100190 (China); Zeng, Xiao-Xiong, E-mail: xxzeng@itp.ac.cn [State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China); School of Material Science and Engineering, Chongqing Jiaotong University, Chongqing 400074 (China)

2017-02-15

The Van der Waals-like phase transition is observed in temperature–thermal entropy plane in spherically symmetric charged Gauss–Bonnet–AdS black hole background. In terms of AdS/CFT, the non-local observables such as holographic entanglement entropy, Wilson loop, and two point correlation function of very heavy operators in the field theory dual to spherically symmetric charged Gauss–Bonnet–AdS black hole have been investigated. All of them exhibit the Van der Waals-like phase transition for a fixed charge parameter or Gauss–Bonnet parameter in such gravity background. Further, with choosing various values of charge or Gauss–Bonnet parameter, the equal area law and the critical exponent of the heat capacity are found to be consistent with phase structures in temperature–thermal entropy plane.

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

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.

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)

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.

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)

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

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

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

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.

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.

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

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.

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.

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.

Ideen zu einer Literatursoziologie des Internets. Mit einer Blogotop-Analyse

Directory of Open Access Journals (Sweden)

Peer Trilcke

2013-11-01

Full Text Available Der Essay skizziert und exemplifiziert die Möglichkeiten einer Literatursoziologie des Internets und plädiert in diesem Zusammenhang für eine Empirisierung der Forschung zu diesem rasant wachsenden, jedoch bisher in seiner Differenziertheit allenfalls oberflächlich beschriebenen Feld der Kommunikation über Literatur. Hierzu werden die literaturwissenschaftlichen Internet Studies und ihr literatursoziologischer Teilbereich innerhalb der allgemeinen Digital Humanities verortet. Als Beispiel für eine in diesem Sinne relational-empirische Literatursoziologie des Internets werden erste Ergebnisse der Analyse eines sog. Bücherblogotops präsentiert, anhand derer sich einige Mechanismen der sekundären literarischen Kommunikation zwar nicht repräsentativ, aber doch exemplarisch diskutieren lassen.

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

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.

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.

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.

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.

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.)

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.)

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)

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.

Plattformbasierte Dienste als technologische Notwendigkeit im disruptiven Marktwandel

Science.gov (United States)

Elsner, Daniel

Die energiewirtschaftliche Digitalisierung führt zu einem disruptiven Marktwandel. Der smarte, vernetzte Energiemarkt von morgen umfasst neue Player, neue Kommunikationsanforderungen, geändertes Kundenverhalten und mehr Daten. Etablierte Marktteilnehmer sind gezwungen, ihre bisherigen Geschäftsmodelle zu überdenken. IT wird dabei mehr und mehr zum Wettbewerbsfaktor. Ein erfolgreiches Managen der technologischen Veränderungsprozesse ist zwingende Voraussetzung für die nachhaltige Bewältigung der energiewirtschaftlichen Digitalisierung. In diesem Zusammenhang erweisen sich die daten- und entwicklungsspezifischen Synergieeffekte plattformbasierter Dienste als zentraler Mehrwert einer innovationsgetriebenen strategischen Marktpositionierung und damit als technologische Notwendigkeit.

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.

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...

Dem Gemeinwohl verpflichtet? Was motiviert die Beschäftigten des öffentlichen Dienstes?

OpenAIRE

Vogel, Dominik

2011-01-01

Die Arbeit befasst sich theoretisch und empirisch mit der so genannten Public Service Motivation (PSM) und ihrem Zusammenhang zu anderen psychologischen Motivationstheorien. Die Public Service Motivation geht davon aus, dass öffentlich Beschäftigte unter anderem dadurch motiviert sind, dass sie in ihrer Arbeit einen Dienst am Gemeinwohl sehen. Auf Basis einer empirischen Erhebung konnte dieses Konstrukt auch für Beschäftigte in Deutschland nachgewiesen und der Einfluss soziodemographischer Va...

Dem Gemeinwohl verpflichtet? - Was motiviert die Beschäftigten des öffentlichen Dienstes?

OpenAIRE

Vogel, Dominik

2011-01-01

Die Arbeit befasst sich theoretisch und empirisch mit der so genannten Public Service Motivation (PSM) und ihrem Zusammenhang zu anderen psychologischen Motivationstheorien. Die Public Service Motivation geht davon aus, dass öffentlich Beschäftigte unter anderem dadurch motiviert sind, dass sie in ihrer Arbeit einen Dienst am Gemeinwohl sehen. Auf Basis einer empirischen Erhebung konnte dieses Konstrukt auch für Beschäftigte in Deutschland nachgewiesen und der Einfluss soziodemographischer Va...

Being stressed and active!? An analysis of different aspects of the relationship between physical activity, individual perceived stress, and individual health

OpenAIRE

Reiner, Miriam

2014-01-01

Die sportwissenschaftliche Forschung zeigt deutlich, dass Sport und körperliche Aktivität positive Effekte für die Gesundheit haben, im Gegensatz dazu aber erlebter Stress negative Folgen hat. Es stellt sich die Frage, welche Rollen und Effekte Sport im Stress-Gesundheit Kontext spielen kann. In drei Studien wurde der Moderatoreffekt von Sport auf den Zusammenhang zwischen Stress und Beschwerden sowie der Effekt von erlebtem Stress auf die Sportaktivität selbst untersucht.

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.

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.

Quantum entanglement for systems of identical bosons: II. Spin squeezing and other entanglement tests

International Nuclear Information System (INIS)

Dalton, B J; Goold, J; Garraway, B M; Reid, M D

2017-01-01

These two accompanying papers are concerned with entanglement for systems of identical massive bosons and the relationship to spin squeezing and other quantum correlation effects. The main focus is on two mode entanglement, but multi-mode entanglement is also considered. The bosons may be atoms or molecules as in cold quantum gases. The previous paper I dealt with the general features of quantum entanglement and its specific definition in the case of systems of identical bosons. Entanglement is a property shared between two (or more) quantum sub-systems. In defining entanglement for systems of identical massive particles, it was concluded that the single particle states or modes are the most appropriate choice for sub-systems that are distinguishable, that the general quantum states must comply both with the symmetrization principle and the super-selection rules (SSR) that forbid quantum superpositions of states with differing total particle number (global SSR compliance). Further, it was concluded that (in the separable states) quantum superpositions of sub-system states with differing sub-system particle number (local SSR compliance) also do not occur. The present paper II determines possible tests for entanglement based on the treatment of entanglement set out in paper I. Several inequalities involving variances and mean values of operators have been previously proposed as tests for entanglement between two sub-systems. These inequalities generally involve mode annihilation and creation operators and include the inequalities that define spin squeezing. In this paper, spin squeezing criteria for two mode systems are examined, and spin squeezing is also considered for principle spin operator components where the covariance matrix is diagonal. The proof, which is based on our SSR compliant approach shows that the presence of spin squeezing in any one of the spin components requires entanglement of the relevant pair of modes. A simple Bloch vector test for

Quantum entanglement for systems of identical bosons: II. Spin squeezing and other entanglement tests

Science.gov (United States)

Dalton, B. J.; Goold, J.; Garraway, B. M.; Reid, M. D.

2017-02-01

These two accompanying papers are concerned with entanglement for systems of identical massive bosons and the relationship to spin squeezing and other quantum correlation effects. The main focus is on two mode entanglement, but multi-mode entanglement is also considered. The bosons may be atoms or molecules as in cold quantum gases. The previous paper I dealt with the general features of quantum entanglement and its specific definition in the case of systems of identical bosons. Entanglement is a property shared between two (or more) quantum sub-systems. In defining entanglement for systems of identical massive particles, it was concluded that the single particle states or modes are the most appropriate choice for sub-systems that are distinguishable, that the general quantum states must comply both with the symmetrization principle and the super-selection rules (SSR) that forbid quantum superpositions of states with differing total particle number (global SSR compliance). Further, it was concluded that (in the separable states) quantum superpositions of sub-system states with differing sub-system particle number (local SSR compliance) also do not occur. The present paper II determines possible tests for entanglement based on the treatment of entanglement set out in paper I. Several inequalities involving variances and mean values of operators have been previously proposed as tests for entanglement between two sub-systems. These inequalities generally involve mode annihilation and creation operators and include the inequalities that define spin squeezing. In this paper, spin squeezing criteria for two mode systems are examined, and spin squeezing is also considered for principle spin operator components where the covariance matrix is diagonal. The proof, which is based on our SSR compliant approach shows that the presence of spin squeezing in any one of the spin components requires entanglement of the relevant pair of modes. A simple Bloch vector test for

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.

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.

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

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...

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.

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.

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.

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

Holographic entanglement entropy and entanglement thermodynamics of 'black' non-susy D3 brane

Science.gov (United States)

Bhattacharya, Aranya; Roy, Shibaji

2018-06-01

Like BPS D3 brane, the non-supersymmetric (non-susy) D3 brane of type IIB string theory is also known to have a decoupling limit and leads to a non-supersymmetric AdS/CFT correspondence. The throat geometry in this case represents a QFT which is neither conformal nor supersymmetric. The 'black' version of the non-susy D3 brane in the decoupling limit describes a QFT at finite temperature. Here we first compute the entanglement entropy for small subsystem of such QFT from the decoupled geometry of 'black' non-susy D3 brane using holographic technique. Then we study the entanglement thermodynamics for the weakly excited states of this QFT from the asymptotically AdS geometry of the decoupled 'black' non-susy D3 brane. We observe that for small subsystem this background indeed satisfies a first law like relation with a universal (entanglement) temperature inversely proportional to the size of the subsystem and an (entanglement) pressure normal to the entangling surface. Finally we show how the entanglement entropy makes a cross-over to the thermal entropy at high temperature.

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.

Measures to enhance rational energy use in electric drives. Final report; Massnahmen zur Foerderung der rationellen Energienutzung bei elektrischen Antrieben. Endbericht

Energy Technology Data Exchange (ETDEWEB)

Reichert, J.; Schleich, J.; Herzer, G.; Toensing, E. [Fraunhofer-Institut fuer Systemtechnik und Innovationsforschung (ISI), Karlsruhe (Germany); Rath, U.; Hellmann, R. [Ingenieurbuero fuer Energieberatung, Haustechnik und Oekologische Konzepte GbR (eboek), Tuebingen (Germany)

1999-05-01

Electric drives account for nearly 60 % of the total power consumption in Germany (70 % in the industrial sector and about 44 % in the small consumer sector). There is a high potential for savings (Landwehr et al. 1996, ISR et al. 1996, Nadel et al. 1992) but it is little used so far. The study attempts to identify and systematize the limits set by the market to the application of energy conservation measures in electric motors. This is followed by an outline of strategies to overcome these obstacles. Experience from other countries are integrated where efforts were made to put the potential savings into practice. [German] Der Kraftstrombedarf fuer elektrische Antriebe betraegt in Deutschland knapp 60% des gesamten Stromeinsatzes (ca. 70% des Industriestrombedarfs und ca. 44% des Strombedarfs im Sektor Kleinverbrauch). Trotz dieser hohen Anteile ist bisher bei keinem der Marktteilnehmer (Motoren- und Anlagenhersteller, Haendler und Endanwender) grosses Interesse an Stromsparmassnahmen im Bereich Elektromotoren zu erkennen. Zudem zeigen erste grobe Schaetzungen (Landwehr et al. 1996, ISR et al. 1996, Nadel et al. 1992), dass im Bereich Elektromotoren erhebliche wirtschaftliche Einsparpotentiale bestehen. Durch eine Erhoehung des Wirkungsgrades allein lassen sich ca. 3% einsparen. Groessere Potentiale koennen durch Drehzahlregelung - ca. 10% - und vor allem bei Optimierung des gesamten Systems (Stromuebertragung - Motor - Regelung - Kraftuebertragung - Arbeitsmaschine) - ueber 20% - erschlossen werden. Ziel dieser Studie ist es, zunaechst die Marktbeschraenkungen bei der Umsetzung von Massnahmen zur rationellen Energienutzung bei Elektromotoren zu identifizieren und zu systematisieren. Im Anschluss daran werden moegliche Strategien zur Ueberwindung dieser Marktbeschraenkungen aufgezeigt, systematisiert und analysiert. In diesem Zusammenhang werden auch Erfahrungen aus anderen Laendern, in denen von politischer und wirtschaftlicher Seite zum Teil betraechtliche

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...

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.

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.

Rezension von: Nancy E. Riley: Gender, Work, and Family in a Chinese Economic Zone. Laboring in Paradise. Wiesbaden: Springer VS 2013.

Directory of Open Access Journals (Sweden)

Yvonne Berger

2015-03-01

Full Text Available Das Buch eignet sich vor allem für Wissenschaftler/-innen, die sich mit den Lebenswirklichkeiten von Arbeitsmigrantinnen in China aus geschlechtertheoretischer Sicht beschäftigen. Nancy E. Riley interessiert sich ethnographisch für den Zusammenhang von Geschlecht, Arbeit und Familie. Konkret geht die Autorin dabei der Frage nach, inwiefern die in der Dalian Economic Zone (DEZ arbeitenden Frauen Erwerbsarbeit als eine Ressource der sozialen Mobilität und der Verhandlung innerfamilialer Machtpositionen nutzbar machen können. Mit Fokus auf dieser (Sonder-Wirtschaftszone und den familialen Lebenswirklichkeiten der Frauen erschließen sich spannende Einsichten in das wirtschaftlich aufstrebende China und den damit einhergehenden sozialen Wandel von Geschlechterverhältnissen.

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

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.

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...

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

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

Die Figur des 'Wetteifers' und ihre Funktion in Kants Ethik

OpenAIRE

Schönwälder-Kuntze, Tatjana

2011-01-01

Im Zentrum des Aufsatzes steht die systematische Funktion des ‚Wetteifers‛ in der praktischen Philosophie Kants. Zwar taucht der ‚Wetteifer‛ in vielfältigem Zusammenhang in Kants Anthropologischen Schriften auf, dennoch wird er in Bezug auf ethische Fragen selten in Betracht gezogen. Auch wenn es richtig ist, dass ‚Wetteifer‛ dort nicht im Sinne des marktwirtschaftlichen Wettbewerbs verwendet wird, handelt es sich doch strukturell um die gleiche interaktionsbasierte Figur – wie wir sie auch i...

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)

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...

Entanglement hamiltonian and entanglement contour in inhomogeneous 1D critical systems

Science.gov (United States)

Tonni, Erik; Rodríguez-Laguna, Javier; Sierra, Germán

2018-04-01

Inhomogeneous quantum critical systems in one spatial dimension have been studied by using conformal field theory in static curved backgrounds. Two interesting examples are the free fermion gas in the harmonic trap and the inhomogeneous XX spin chain called rainbow chain. For conformal field theories defined on static curved spacetimes characterised by a metric which is Weyl equivalent to the flat metric, with the Weyl factor depending only on the spatial coordinate, we study the entanglement hamiltonian and the entanglement spectrum of an interval adjacent to the boundary of a segment where the same boundary condition is imposed at the endpoints. A contour function for the entanglement entropies corresponding to this configuration is also considered, being closely related to the entanglement hamiltonian. The analytic expressions obtained by considering the curved spacetime which characterises the rainbow model have been checked against numerical data for the rainbow chain, finding an excellent agreement.

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

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.

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)

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)

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.

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...

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.

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

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

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

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

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.

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.

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.

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.

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

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.

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.

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

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)

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.

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

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

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.

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.

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

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.

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.

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.

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.

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

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.

Solar cooling - implementation of intelligent concepts; Solare Kuehlung - intelligente Konzepte werden Realitaet

Energy Technology Data Exchange (ETDEWEB)

Puettmer, M. [Goetz GmbH, Metall- und Anlagenbau, Fellbach (Germany); Kranz, H.R. [Siemens AG, Karlsruhe (Germany)

1995-12-31

In chapter 11 of the anthology about building control the subject solar cooling is described. The following aspects are discussed: changed preconditions for thermal building concepts, building facades and energy supply - one unit. Can cold be economically generated by solar energy? (BWI) [Deutsch] Kapitel 11 des Sammelbandes ueber Building Control ist dem Thema der solaren Kuehlung gewidmet. In diesem Zusammenhang werden folgende Themenkreise angesprochen: Geaenderte Voraussetzungen fuer thermische Gebaeudekonzepte; Gebaeudefassade und Energieversorgung: eine Einheit; Kann Kaelte mit der Sonne wirtschaftlich erzeugt werden? (BWI)

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.

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...

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.

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.

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...

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)

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.

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.

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

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

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.

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)

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.

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 .

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.

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.

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.

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.

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

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.

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.

Die FPÖ im internationalen Vergleich - Zwischen Rechtspopulismus, Deutschnationalismus und Österreich-Patriotismus

Directory of Open Access Journals (Sweden)

Anton Pelinka

2002-04-01

Full Text Available Die Freiheitliche Partei Österreichs (FPÖ fällt im europäischen Kontext deshalb auf, weil sie die erfolgreichste der Parteien ist, die mit dem Begriff "Rechtspopulismus" bezeichnet werden. Der Beitrag versucht, die Erfolge der FPÖ bei Wahlen aus den Rahmenbedingungen des österreichischen politischen Systems und der österreichischen Gesellschaft zu erklären. Das als "hyperstabil" bezeichnete politische System Österreichs hat in den letzten 20 bis 25 Jahren signifikante Veränderungen durchgemacht. Die Erfolge der FPÖ sind eine Begleiterscheinung dieser Veränderungen - weder deren Ursache, noch deren Auslöser. Dies wird umso deutlicher, wenn die Veränderungen der österreichischen Gesellschaft und ihrer politischen Kultur in die Analyse einbezogen werden: Zuerst begann sich die Loyalität innerhalb der politisch-weltanschaulichen Lager aufzulösen - und dann erst begann der Aufstieg der FPÖ von einer kleinen, um Respektabilität bemühten Partei zu einer ihre Außenseiterrolle betonenden Protestpartei. Die Besonderheit der FPÖ, die sich auch in der europäischen Reaktion auf ihre Regierungsbeteiligung seit dem Februar 2000 äußerte, muss auch aus der Vorgeschichte der Zweiten Republik allgemein und der Freiheitlichen Partei im besonderen erklärt werden. Darin spiegelt sich auch der Zusammenhang zwischen der Entwicklung österreichischer Identität von einer transnationalen über eine deutschnationale zu einer spezifisch österreichischen nationalen Identität. Die in dieser Entwicklung zum Ausdruck kommenden Brüche werden in der Widersprüchlichkeit der FPÖ zugespitzt verdeutlicht: In ihren deutschnationalen Wurzeln verkörpert die FPÖ die Absage an die Konvergenz von Staat und Nation; in ihrer "populistischen" Orientierung ist die Partei aber österreichisch-patriotisch. Die FPÖ ist schließlich auch in der sozialen Struktur ihrer Wählerschaft zu begreifen: Die Partei artikuliert vor allem die Interessen der

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.)

Strong monotonicity in mixed-state entanglement manipulation

International Nuclear Information System (INIS)

Ishizaka, Satoshi

2006-01-01

A strong entanglement monotone, which never increases under local operations and classical communications (LOCC), restricts quantum entanglement manipulation more strongly than the usual monotone since the usual one does not increase on average under LOCC. We propose strong monotones in mixed-state entanglement manipulation under LOCC. These are related to the decomposability and one-positivity of an operator constructed from a quantum state, and reveal geometrical characteristics of entangled states. These are lower bounded by the negativity or generalized robustness of entanglement

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

Teleportation of Entangled States through Divorce of Entangled Pair Mediated by a Weak Coherent Field in a High-Q Cavity

Institute of Scientific and Technical Information of China (English)

W. B. Cardosol; N. G. de Almeida

2008-01-01

We propose a scheme to partially teleport an unknown entangled atomic state. A high-Q cavity, supporting one mode of a weak coherent state, is needed to accomplish this process. By partial teleportation we mean that teleportation will occur by changing one of the partners of the entangled state to be teleported. The entangled state to be teleported is composed by one pair of particles, we called this surprising characteristic of maintaining the entanglement, even when one of the particle of the entangled pair being teleported is changed, of divorce of entangled states.

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.

Ästhetisches Bild und Christliche Mystik im Cántico espiritual des San Juans de la Cruz

DEFF Research Database (Denmark)

Kluge, Sofie

2003-01-01

  In diesem Zusammenhang werde ich, von dem Cántico espiritual des San Juans de la Cruz (1577) ausgehend und zentrale rezeptionsgeschichtliche Probleme einbeziehend, den mystischen Bildbegriff untersuchen. Auf der einen Seite bildet San Juans selbstständige Interpretation des biblischen Hoheliedes...... macht somit den übergeordneten Rahmen meiner Interpretation und Diskussion des Cántico espiritual mit dazugehörigen Prosakommentaren aus. Weil der Cántico espiritual als mysticher Text behauptet, er beschreibt eine paranormale Erfahrung (die unio mystica als intenses Gotteserlebnis), ist es relevant...

And the Roads Lead to Nowhere : die Jungfrauenquelle und Last House on the Left als Transformationen

OpenAIRE

Köhne, Julia; Renz, Tilo

2010-01-01

Wes Cravens Last House on the Left (1972) ist ein Vorläufer des Rape-Revenge- enres, in dem auf eine Vergewaltigung gewaltsame Rache folgt. Er gehört zu denjenigen Filmen, die sich durch die Visualisierung exzessiver am Körper, am Fleisch verübter Gewalt auszeichnen und daher als Splatter bezeichnet werden. Die Entstehung des Splatterfilms wird mit der kulturellen Situation in den USA der Vietnam-Ära in Zusammenhang gebracht. Als filmische Vorläufer gelten Hitchcocks Psycho (1960) sowie frühe...

Building system technology with installation bus. Planning now for the future; Gebaeudesystemtechnik - mit Installationsbus. Heute schon an morgen denken

Energy Technology Data Exchange (ETDEWEB)

Vogt, D. [RWE Energie AG, Essen (Germany)

1995-12-31

In chapter 16 of the anthology about building technology the building system technology with installation bus is described. The following aspects are discussed: limits of the conventional electric installation, building system technology, building system technology - illusion or reality?; The European Installation Bus Association (EIBA). (BWI) [Deutsch] Kapitel 16 des Sammelbandes ueber Building Control ist dem Thema der Gebaeudesystemtechnik mit Installationsbus gewidmet. In diesem Zusammenhang werden folgende Themenbereiche angesprochen: Grenzen der konventionellen Elektroinstallation; Gebaeudesystemtechnik; Gebaeudesystemtechnik - Illusion oder Realitaet?; Die EIBA (European Installation Bus Association). (BWI)

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)

Archivierungsstrategien für qualitative Daten

Directory of Open Access Journals (Sweden)

Andrea Smioski

2013-07-01

Full Text Available Durch die Ausweitung qualitativer Forschung gerät die Frage nach dem Umgang mit qualitativen Forschungsdaten immer mehr in den Fokus der Aufmerksamkeit. Große Archive verfügen mittlerweile über spezialisierte Einrichtungen für die Archivierung qualitativer Daten. Diese erfordern jedoch andere Archivierungsstrategien als quantitative Daten: Datendokumentation spielt eine größere Rolle für die Sekundärauswertung, Vertraulichkeitsfragen und datenschutzrechtliche Aspekte müssen stärker berücksichtigt werden etc. Ausgehend von verschiedenen Archivierungsstrategien für qualitative Daten wird in diesem Artikel aufgezeigt, wie eng Archivierungsprozesse mit Forschungsprozessen verknüpft sind und was das für den Lebenszyklus von Daten bedeutet. Als in diesem Zusammenhang wichtige Option wird das Konzept der living archives eingeführt: Durch Weiternutzung archivierter Daten können Bestände wachsen und langfristig an Wert gewinnen. Schließlich wird diskutiert, wie Datenarchivierung zur Güte qualitativer Forschung beitragen kann und welche Bedeutung Archiven in diesem Zusammenhang zukommt. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs130350

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 ...

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.

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.

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.

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.

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.

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.

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.

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.

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.

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...

Entanglement capacity of nonlocal Hamiltonians: A geometric approach

International Nuclear Information System (INIS)

Lari, Behzad; Hassan, Ali Saif M.; Joag, Pramod S.

2009-01-01

We develop a geometric approach to quantify the capability of creating entanglement for a general physical interaction acting on two qubits. We use the entanglement measure proposed by us for N-qubit pure states [Ali Saif M. Hassan and Pramod S. Joag, Phys. Rev. A 77, 062334 (2008)]. This geometric method has the distinct advantage that it gives the experimentally implementable criteria to ensure the optimal entanglement production rate without requiring a detailed knowledge of the state of the two qubit system. For the production of entanglement in practice, we need criteria for optimal entanglement production, which can be checked in situ without any need to know the state, as experimentally finding out the state of a quantum system is generally a formidable task. Further, we use our method to quantify the entanglement capacity in higher level and multipartite systems. We quantify the entanglement capacity for two qutrits and find the maximal entanglement generation rate and the corresponding state for the general isotropic interaction between qutrits, using the entanglement measure of N-qudit pure states proposed by us [Ali Saif M. Hassan and Pramod S. Joag, Phys. Rev. A 80, 042302 (2009)]. Next we quantify the genuine three qubit entanglement capacity for a general interaction between qubits. We obtain the maximum entanglement generation rate and the corresponding three qubit state for a general isotropic interaction between qubits. The state maximizing the entanglement generation rate is of the Greenberger-Horne-Zeilinger class. To the best of our knowledge, the entanglement capacities for two qutrit and three qubit systems have not been reported earlier.

Teleportation of Entangled States through Divorce of Entangled Pair Mediated by a Weak Coherent Field in a High-Q Cavity

International Nuclear Information System (INIS)

Cardoso, W. B.; Almeida, N. G. de

2008-01-01

We propose a scheme to partially teleport an unknown entangled atomic state. A high-Q cavity, supporting one mode of a weak coherent state, is needed to accomplish this process. By partial teleportation we mean that teleportation will occur by changing one of the partners of the entangled state to be teleported. The entangled state to be teleported is composed by one pair of particles, we called this surprising characteristic of maintaining the entanglement, even when one of the particle of the entangled pair being teleported is changed, of divorce of entangled states. (fundamental areas of phenomenology (including applications))

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.

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.

Interaktive E-Learning-Module in der Humangenetik: Einsatz und Evaluation im Rahmen der Medizinstudierenden- und Humanbiologen-Ausbildung [Interactive e-learning courses in human genetics: Usage and evaluation by science and medical students at the faculty of medicin

Directory of Open Access Journals (Sweden)

Oeffner, Frank

2011-08-01

Full Text Available [english] Introduction: This study presents our online-teaching material within the k-MED project (Knowledge in Medical Education at the university of Marburg. It is currently organized in five e-learning modules: cytogenetics, chromosomal aberrations, formal genetics, fundamentals of molecular diagnostics, and congenital abnormalities and syndromes. These are basic courses intended to do the educational groundwork, which will enable academic teachers to concentrate on more sophisticated topics during their lectures. Methods: The e-learning modules have been offered to a large group of about 3300 students during four years at the Faculty of Medicine in Marburg. The group consists of science students (human biology and medical students in the preclinical or the clinical period, respectively. Participants were surveyed on acceptance by evaluating user-tracking data and questionnaires. Results and Conclusion: Analysis of the evaluation data proofs the broad acceptance of the e-learning modules during eight semesters. The courses are in stable or even increasing use from winter term 2005/06 until spring term 2009.Conclusion: Our e-learning-model is broadly accepted among students with different levels of knowledge at the Faculty of Medicine in Marburg. If the e-learning courses are maintained thoroughly, minor adaptations can increase acceptance and usage even furthermore. Their use should be extended to the medical education of technical assistances and nurses, who work in the field of human genetics.[german] Einleitung: Die vorliegende Studie beschreibt unser Online-Lehrmaterial Humangenetik im Zusammenhang mit dem k-MED-Projekt (Knowledge in Medical Education an der Philipps-Universität Marburg. Es besteht aus fünf E-Learning-Modulen: Zytogenetik, Chromosomenstörungen, Formalgenetik, Grundlagen der molekularen Diagnostik sowie Kongenitale Abnormitäten und Fehlbildungssyndrome. Diese E-Module sollen ein einheitliches Wissensniveau der

„Wer waren Deine wichtigsten Lehrer?“ [“Who were your most important teachers?”

Directory of Open Access Journals (Sweden)

Haux, Reinhold

2013-11-01

Full Text Available [english] On May 22nd, 2013 a symposium on “medical informatics – perspectives of a scientific discipline” took place at the University of Braunseig, Germany. In this context the editor of MIBE asked me, who my most important teachers were. This essay is an attempt to answer this question.[german] Im Zusammenhang mit einem Symposium zum Thema „Medizinische Informatik – Perspektiven einer wissenschaftlichen Disziplin“, welches am 22.5.2013 an der TU Braunschweig stattfand, wurde mir von dem Herausgeber der MIBE die Frage gestellt, wer meine wichtigsten Lehrer waren. In der vorliegenden Ausarbeitung wird versucht, eine Antwort auf diese Frage zu geben.

Single room control for user-optimised room air conditions; Einzelraumregelung fuer nutzungsoptimiertes Raumklima

Energy Technology Data Exchange (ETDEWEB)

Lezius, A. [Staefa Control System GmbH, Leinfelden-Echterdingen (Germany)

1995-12-31

In chapter 14 of the anthology about building control the single room control for achieving user-optimised room air conditions is described. The following aspects are discussed: What is comfort? What is economic efficiency? Systems for secondary air treatment, adapted functions of the measurement and control technique, management functions, orientation of the demand at the use, investment and amortisation. (BWI) [Deutsch] Kapitel 14 des Sammelbandes ueber Building control ist dem Thema der Einzelraumregelung zur Erzielung eines nutzungsoptimierten Raumklimas gewidmet. In diesem Zusammenhang werden folgende Themenbereiche angesprochen: Was ist Komfort? Was ist Wirtschaftlichkeit? Systeme fuer sekundaere Luftbehandlung; Angepasste Funktionen der MSR-Technik; Managementfunktionen; Bedarfsorientierung an der Nutzung; Investition und Amortisation. (BWI)

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.

Platz der Östrogene in der Primärprävention der Osteoporose

Directory of Open Access Journals (Sweden)

Birkhäuser M

2011-01-01

Full Text Available Die Gabe von Östrogenen allein (EET oder Östrogene + Gestagen (HET führt zu einer signifikanten Senkung des Frakturrisikos. Die Osteoporoseprävention bleibt in der frühen Postmenopause nach Meinung der Schweizerischen (SMG, der Europäischen (EMAS und der Internationalen (IMS Menopausengesellschaften einer der gesicherten Nutzen einer Östrogengabe und somit eine Therapie der ersten Wahl zur Frakturprävention bei Frauen in der Peri- und frühen Postmenopause. Bei schweren klimakterischen Beschwerden sind EET oder HET das unbestritten wirksamste Therapieprinzip (Hauptindikation einer EET/HET. Die gleichzeitig gesicherte Frakturprävention ist bei der Behandlung des klimakterischen Syndroms ein erwünschter günstiger Nebeneffekt. Jede EET/HET muss individualisiert sein und soll nur solange erfolgen, als sie notwendig ist. Bei gegebener Indikation kann die EET oder HET über die üblichen 3–5 Jahre hinaus fortgesetzt werden. Bei vorzeitiger Menopause (vor dem 40. Altersjahr und früher Menopause (vor dem 45. Altersjahr besteht eine absolute Indikation zum Beginn einer EET/HET. Frauen mit vorzeitiger Ovarialinsuffizienz benötigen meist höhere Dosierungen als solche mit zeitgerechter Menopause. Die EET/HET soll auch aus Gründen der Osteoporoseprävention mindestens bis zum normalen Menopausenalter weitergeführt werden (51– 52 Jahre. Bei Beginn einer HET innerhalb von 10 Jahren nach der Menopause oder in einem Alter von bis zu 60 Jahren überwiegt bei gegebener Indikation der Nutzen die Risiken. Dies muss bei der Behandlungswahl bei jüngeren postmenopausalen Frauen mit erhöhtem Osteoporoserisiko wieder vermehrt berücksichtigt werden, vor allem, wenn gleichzeitig klimakterische Beschwerden vorliegen.

Thermal entanglement and teleportation of a thermally mixed entangled state of a Heisenberg chain through a Werner state

Institute of Scientific and Technical Information of China (English)

Huang Li-Yuan; Fang Mao-Fa

2008-01-01

The thermal entanglement and teleportation of a thermally mixed entangled state of a two-qubit Heisenberg XXX chain under the Dzyaloshinski-Moriya (DM) anisotropic antisymmetric interaction through a noisy quantum channel given by a Werner state is investigated. The dependences of the thermal entanglement of the teleported state on the DM coupling constant, the temperature and the entanglement of the noisy quantum channel are studied in detail for both the ferromagnetic and the antiferromagnetic cases. The result shows that a minimum entanglement of the noisy quantum channel must be provided in order to realize the entanglement teleportation. The values of fidelity of the teleported state are also studied for these two cases. It is found that under certain conditions, we can transfer an initial state with a better fidelity than that for any classical communication protocol.

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 ...

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.

Wie viel muss ich wissen, um global handeln zu können? Verantwortung für Weltarmut und das Problem der epistemischen Überforderung

Directory of Open Access Journals (Sweden)

Weber-Guskar Eva

2015-12-01

Full Text Available Was heißt es, sich in unserer globalisierten Welt als eine vollverantwortliche Person zu verstehen und zu verhalten? Einerseits scheint es richtig, dass wir global verantwortlich sind, d.h. dass wir auch gegen entferntes Leid etwas tun sollten; andererseits aber ist wegen vielfacher Überforderungsproblemen unklar ist, wie man diese Verantwortung tatsächlich übernehmen können soll – was wiederum dagegen spricht, dass wir diese Verantwortung berechtigtermaßen zuschreiben können. Um einen Aspekt dieses großen Themas zu behandeln, konzentriere ich mich in diesem Aufsatz auf den Anwendungsbereich von extremer Armut und argumentiere in folgenden Schritten. Zuerst spitze ich das Thema zu auf ein Problem, das Samuel Scheffler in diesem Zusammenhang konstatiert hat, nämlich einen Widerstreit zwischen dem, was Verantwortung unter den Bedingungen der Globalisierung bedeutet und dem, wie wir uns grundsätzlich als Handelnde zu verstehen gewohnt sind. Dann zeige ich erstens, dass dem Thema einer epistemischen Überforderung dabei entscheidendes Gewicht zugesprochen wird, zweitens jedoch, dass sich, genauer besehen, dieses Problem gar nicht in dieser Art stellt. Dafür schlage ich eine Analyse des Verantwortungsbegriffs vor, die es ermöglicht, Kriterien zu identifizieren, anhand derer gewisse Grenzen gezogen werden können, so dass die Zuschreibung der Verantwortung gerechtfertigt werden kann.

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

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.

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.

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.

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...

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

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.

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

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)

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.

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.

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

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

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.

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＞.

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)

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)

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...

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.

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...

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.

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.

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.

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.

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.

Measurement-Device-Independent Approach to Entanglement Measures

Science.gov (United States)

Shahandeh, Farid; Hall, Michael J. W.; Ralph, Timothy C.

2017-04-01

Within the context of semiquantum nonlocal games, the trust can be removed from the measurement devices in an entanglement-detection procedure. Here, we show that a similar approach can be taken to quantify the amount of entanglement. To be specific, first, we show that in this context, a small subset of semiquantum nonlocal games is necessary and sufficient for entanglement detection in the local operations and classical communication paradigm. Second, we prove that the maximum payoff for these games is a universal measure of entanglement which is convex and continuous. Third, we show that for the quantification of negative-partial-transpose entanglement, this subset can be further reduced down to a single arbitrary element. Importantly, our measure is measurement device independent by construction and operationally accessible. Finally, our approach straightforwardly extends to quantify the entanglement within any partitioning of multipartite quantum states.

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 ...

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

Sectoral clusters as new trajectories of great promise. Business networks and regional innovation systems: The German rail vehicle industry for example; Hoffnungstraeger Wirtschaftscluster. Unternehmensnetzwerke und regionale Innovationssysteme: Das Beispiel der deutschen Schienenfahrzeugindustrie

Energy Technology Data Exchange (ETDEWEB)

Dybe, G.; Kujath, H.J.

2000-07-01

funktionale und raeumliche Cluster? Wie veraendern sich derartige Cluster im Lebenszyklus der Produkte und Industrien (Pfadabhaengigkeit)? Und welche Wechselwirkungen gibt es zwischen dem raeumlichen Kontext der Region und dem Beziehungsnetz der Wirtschaft und des Wissenssystems? Am Beispiel der Systemtechnologie Schienenfahrzeugbau wird der Zusammenhang zwischen den materiellen Verflechtungsstrukturen und den Netzen des Wissensaustausches behandelt sowie empirisch fuer die Region Berlin-Brandenburg vertieft. Die Untersuchung demonstriert die Grenzen der bislang vorliegenden theoretischen Ansaetze zur regionalen Clusterbildung und weist der Theorieentwicklung neue Wege. (orig.)

Die Wirksamkeit von Medienbildungsinitiativen: Erfolge, Probleme und Lösungsansätze

Directory of Open Access Journals (Sweden)

Yvonne Ludewig

2013-09-01

Full Text Available Neben der Persönlichkeitsbildung obliegt der Schule ein Qualifizierungsauftrag (KMK 2012, 3. Im Zusammenhang dieses Auftrags, Schülerinnen und Schüler auf das (Berufs- Leben vorzubereiten, hielten digitale Medien Einzug in nahezu alle Schulformen. Dort sollen sie neben der Förderung der Medienkompetenz in allen ihren Ausprägungen auf Seiten der Schülerinnen und Schüler, zudem die Lehr- und Lernkultur verbessern. Mit Hilfe landes- und städteweiter Initiativen wird dabei die Medienintegration und konkrete Mediennutzung vorangetrieben, wie bspw. durch die Medienbildungsinitiative der Stadt Frankfurt am Main, deren Erfolge, Probleme und Lösungsansätze nach zehnjährigem Bestehen in diesem Artikel betrachtet werden. Ziel war es dabei, den aktuellen Entwicklungsstand, noch bestehende Probleme und vor allem deren mögliche Lösung aus Perspektive der Lehrkräfte darzustellen. Insgesamt wurden Mängel bei der IT-Infrastruktur, den mediendidaktischen Unterstützungsangeboten und hinderliche organisatorische Rahmenbedingungen identifiziert.

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.

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.

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.

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)

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)

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.

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.

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.

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

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.

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.

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-.

Entanglement model of homeopathy as an example of generalized entanglement predicted by weak quantum theory.

Science.gov (United States)

Walach, H

2003-08-01

Homeopathy is scientifically banned, both for lack of consistent empirical findings, but more so for lack of a sound theoretical model to explain its purported effects. This paper makes an attempt to introduce an explanatory idea based on a generalized version of quantum mechanics (QM), the weak quantum theory (WQT). WQT uses the algebraic formalism of QM proper, but drops some restrictions and definitions typical for QM. This results in a general axiomatic framework similar to QM, but more generalized and applicable to all possible systems. Most notably, WQT predicts entanglement, which in QM is known as Einstein-Podolsky-Rosen (EPR) correlatedness within quantum systems. According to WQT, this entanglement is not only tied to quantum systems, but is to be expected whenever a global and a local variable describing a system are complementary. This idea is used here to reconstruct homeopathy as an exemplification of generalized entanglement as predicted by WQT. It transpires that homeopathy uses two instances of generalized entanglement: one between the remedy and the original substance (potentiation principle) and one between the individual symptoms of a patient and the general symptoms of a remedy picture (similarity principle). By bringing these two elements together, double entanglement ensues, which is reminiscent of cryptographic and teleportation applications of entanglement in QM proper. Homeopathy could be a macroscopic analogue to quantum teleportation. This model is exemplified and some predictions are derived, which make it possible to test the model. Copyright 2003 S. Karger GmbH, Freiburg

Statistical bounds on the dynamical production of entanglement

International Nuclear Information System (INIS)

Abreu, Romulo F.; Vallejos, Raul O.

2007-01-01

We present a random-matrix analysis of the entangling power of a unitary operator as a function of the number of times it is iterated. We consider unitaries belonging to the circular ensembles of random matrices [the circular unitary (CUE) or circular orthogonal ensemble] applied to random (real or complex) nonentangled states. We verify numerically that the average entangling power is a monotonically decreasing function of time. The same behavior is observed for the 'operator entanglement' - an alternative measure of the entangling strength of a unitary operator. On the analytical side we calculate the CUE operator entanglement and asymptotic values for the entangling power. We also provide a theoretical explanation of the time dependence in the CUE cases

Experimental observation of entanglement duality for identical particles

International Nuclear Information System (INIS)

Ma, J-J; Yuan, X-X; Zu, C; Chang, X-Y; Hou, P-Y; Duan, L-M

2014-01-01

It was shown recently that entanglement of identical particles has a feature called dualism (Bose and Home 2013 Phys. Rev. Lett. 110 140404), which is fundamentally connected with quantum indistinguishability. Here we report an experiment that observes the entanglement duality for the first time with two identical photons, which manifest polarization entanglement when labeled by different paths or path entanglement when labeled by polarization states. By adjusting the mismatch in frequency or arrival time of the entangled photons, we tune the photon indistinguishability from the quantum to the classical limit and observe that the entanglement duality disappears under the emergence of classical distinguishability, confirming it as a characteristic feature of quantum indistinguishable particles. (paper)

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.

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

Optomechanical entanglement via non-degenerate parametric interactions

Science.gov (United States)

Ahmed, Rizwan; Qamar, Shahid

2017-10-01

We present a scheme for the optomechanical entanglement between a micro-mechanical mirror and the field inside a bimodal cavity system using a non-degenerate optical parametric amplifier (NOPA). Our results show that the introduction of NOPA makes the entanglement stronger or more robust against the mean number of average thermal phonons and cavity decay. Interestingly, macroscopic entanglement depends upon the choice of the phase associated with classical field driving NOPA. We also consider the effects of input laser power on optomechanical entanglement.

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.

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.

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...

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.

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.

Initial conditions and entanglement sudden death

International Nuclear Information System (INIS)

Qian, Xiao-Feng; Eberly, J.H.

2012-01-01

We report results bearing on the behavior of non-local decoherence and its potential for being managed or even controlled. The decoherence process known as entanglement sudden death (ESD) can drive prepared entanglement to zero at the same time that local coherences and fidelity remain non-zero. For a generic ESD-susceptible Bell superposition state, we provide rules restricting the occurrence and timing of ESD, amounting to management tools over a continuous variation of initial conditions. These depend on only three parameters: initial purity, entanglement and excitation. Knowledge or control of initial phases is not needed. -- Highlights: ► We study the possibility of managing disentanglement through initial conditions. ► The initial parameters are the amount of entanglement, excitation, and purity. ► Entanglement sudden death (ESD) free and ESD susceptible phases are identified. ► ESD onset time is also presented in the ESD susceptible phase. ► Our results may guide experiments to prepare ESD free or delayed ESD states.

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.

Entanglement of purification: from spin chains to holography

Science.gov (United States)

Nguyen, Phuc; Devakul, Trithep; Halbasch, Matthew G.; Zaletel, Michael P.; Swingle, Brian

2018-01-01

Purification is a powerful technique in quantum physics whereby a mixed quantum state is extended to a pure state on a larger system. This process is not unique, and in systems composed of many degrees of freedom, one natural purification is the one with minimal entanglement. Here we study the entropy of the minimally entangled purification, called the entanglement of purification, in three model systems: an Ising spin chain, conformal field theories holographically dual to Einstein gravity, and random stabilizer tensor networks. We conjecture values for the entanglement of purification in all these models, and we support our conjectures with a variety of numerical and analytical results. We find that such minimally entangled purifications have a number of applications, from enhancing entanglement-based tensor network methods for describing mixed states to elucidating novel aspects of the emergence of geometry from entanglement in the AdS/CFT correspondence.

Controlling bi-partite entanglement in multi-qubit systems

International Nuclear Information System (INIS)

Plesch, Martin; Novotny, Jaroslav; Dzurakova, Zuzana; Buzek, VladimIr

2004-01-01

Bi-partite entanglement in multi-qubit systems cannot be shared freely. The rules of quantum mechanics impose bounds on how multi-qubit systems can be correlated. In this paper, we utilize a concept of entangled graphs with weighted edges in order to analyse pure quantum states of multi-qubit systems. Here qubits are represented by vertexes of the graph, while the presence of bi-partite entanglement is represented by an edge between corresponding vertexes. The weight of each edge is defined to be the entanglement between the two qubits connected by the edge, as measured by the concurrence. We prove that each entangled graph with entanglement bounded by a specific value of the concurrence can be represented by a pure multi-qubit state. In addition, we present a logic network with O(N 2 ) elementary gates that can be used for preparation of the weighted entangled graphs of N qubits

Controlling bi-partite entanglement in multi-qubit systems

Science.gov (United States)

Plesch, Martin; Novotný, Jaroslav; Dzuráková, Zuzana; Buzek, Vladimír

2004-02-01

Bi-partite entanglement in multi-qubit systems cannot be shared freely. The rules of quantum mechanics impose bounds on how multi-qubit systems can be correlated. In this paper, we utilize a concept of entangled graphs with weighted edges in order to analyse pure quantum states of multi-qubit systems. Here qubits are represented by vertexes of the graph, while the presence of bi-partite entanglement is represented by an edge between corresponding vertexes. The weight of each edge is defined to be the entanglement between the two qubits connected by the edge, as measured by the concurrence. We prove that each entangled graph with entanglement bounded by a specific value of the concurrence can be represented by a pure multi-qubit state. In addition, we present a logic network with O(N2) elementary gates that can be used for preparation of the weighted entangled graphs of N qubits.

О связях прусских гидронимов с названиями животных и птиц

Directory of Open Access Journals (Sweden)

Feliksas Daubaras

2011-07-01

Full Text Available ÜBER BEZIEHUNGEN DER ALTPREUSSISCHEN GEWÄSSERNAMEN ZU TIER- bzw. VOGELNAMENZusammenfassungIm vorliegenden Artikel wird der derivative Zusammenhang der altpr. Gewässernamen mit Tier- bzw. Vogelnamen behandelt. Dabei werden die hidronymischen Parallelen der anderen baltischen Sprachen angeführt. Bei einer gewissen Anzahl von altpr. Gewässernamen läßt sich die­ser derivative Zusammenhang mit Tier- bzw. Vogelnamen mit viel Wahrscheinlichkeit feststellen, z. B. Bebra — altpr. bebrus „Biber“, Gerthin — altpr. gerto „Henne“, gertis „Hahn“, Gulbig — altpr. gulbis „Schwan“, Geyserich — altpr. geeyse „Reiher“, Iwanthi — lit. ývas „Uhu“, Kavnyne — altpr. caune „Marder“, Lusygeynen — altpr. luysis „Luchs“, Serenappe — lit. šérnas „Wildschwein“Sirgun — altpr. sirgis „Hengst“, Suna — altpr. sunis „Hund“. Jedoch der äußere Gleichklang bei Tier- bzw. Vogel- und Gewässernamen kann manchmal auch zufällig sein. In solchen Fällen ist es schwer zu unterscheiden, ob der Gewässername auf einen Tier- bzw. Vogelnamen oder auf ei­ne idg. (bzw. baltische Wurzel zurückzuführen ist, z. B. Alne — altpr. alne „tyer“ oder idg. *el-/*ol- „fliesen, strömen“, Arelen — altpr. arelis „Adler“ oder idg. *ar-(*er-/*or- „in Bewegung setzen, erregen“, Asswene — lit. ašvà „Stute“ oder lat. aqua, got. ahva „Wasser, Jawthe — lit. jáutis „Ochse“ oder lit. jáuti „vermischen“, lett. jaut „mischen“, Warne — altpr. warne „Krähe“ oder idg. *uer-/*uor-  „Wasser, Regen, Fluß“, Wilkus — altpr. wilkis „Wolf“ oder lit. vil̃kti, lett. vilkt „schleppen, ziehen“.

Ein Versuch, Naturverhältnisse aus feministischer Sicht zu interpretieren

Directory of Open Access Journals (Sweden)

Helga Purgand

2002-07-01

Full Text Available Mit dem vorliegenden Sammelband Geschlechterverhältnisse – Naturverhältnisse wird nach dem innovativen Beitrag der feministischen Debatte für umweltsoziologisches Denken gefragt und nach Überschneidungen, Grenzen und Zwischenräumen zwischen „Geschlecht“ und „Natur“ gesucht. In ihm wird der lobenswerte Versuch unternommen, einen Zusammenhang zwischen Geschlechter- und Naturverhältnissen herzustellen „die in der Umweltsoziologie bislang stark vernachlässigte feministische Diskussion und Geschlechterforschung einzubeziehen und als genderbezogene Perspektive zu etablieren“. (S. 9 Das Buch enthält Beiträge von 15 Autorinnen, die unterschiedliche Natur- und Geschlechtsverhältnisse facettenreich, überwiegend kreativ und theoretisch anspruchsvoll betrachten. Das Buch enthält Zugänge aus der allgemeinen Soziologie, den Sprach- und Kulturwissenschaften, aus politik- und naturwissenschaftlichen Zusammenhängen. Den ausdrücklich formulierten Anspruch, von multi- zu einer inter-disziplinären Durchdringung zu gelangen, erfüllt es nur in Ansätzen (besonders mit der Einleitung und den theoretischen Problemexplikationen. Das zustande gekommene „Nach-, Zusammen- und Querdenken“ über Begriffe, Theorien und neuere Forschungsansätze (von Foucault über Butler bis zu Donna Haraway belegt die Notwendigkeit, die naturwissenschaftlichen Annahmen „immanent zu dekonstruieren“. Sehr aufschlussreich sind in diesem Zusammenhang die Beiträge von Irmgard Schultz, Elvira Scheich, aber auch von Mary Mellor und besonders von Paula-Irene Villa, die interessante und kreative Gedanken zur Klärung des Verhältnisses von Natur, Kultur und Geschlecht anbieten. Deutlich wurde, dass weiterhin ein kontroverses Ringen um angemessene konzeptionelle Fassungen von Geschlechts- und Naturverhältnissen und die Integration von Gender als zentraler analytischer Querschnitts-Kategorie nötig sind. Insgesamt ist dem Buch ist eine schnelle Verbreitung und

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....

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...

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.

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.

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).

Optomechanical entanglement via non-degenerate parametric interactions

International Nuclear Information System (INIS)

Ahmed, Rizwan; Qamar, Shahid

2017-01-01

We present a scheme for the optomechanical entanglement between a micro-mechanical mirror and the field inside a bimodal cavity system using a non-degenerate optical parametric amplifier (NOPA). Our results show that the introduction of NOPA makes the entanglement stronger or more robust against the mean number of average thermal phonons and cavity decay. Interestingly, macroscopic entanglement depends upon the choice of the phase associated with classical field driving NOPA. We also consider the effects of input laser power on optomechanical entanglement. (paper)

Multipartite entanglement via the Mayer-Vietoris theorem

Science.gov (United States)

Patrascu, Andrei T.

2017-10-01

The connection between entanglement and topology manifests itself in the form of the ER-EPR duality. This statement however refers to the maximally entangled states only. In this article I study the multipartite entanglement and the way in which it relates to the topological interpretation of the ER-EPR duality. The 2 dimensional genus 1 torus will be generalised to a n-dimensional general torus, where the information about the multipartite entanglement will be encoded in the higher inclusion maps of the Mayer-Vietorist sequence.

Continuous-variable entanglement sharing in noninertial frames

International Nuclear Information System (INIS)

Adesso, Gerardo; Fuentes-Schuller, Ivette; Ericsson, Marie

2007-01-01

We study the distribution of entanglement between modes of a free scalar field from the perspective of observers in uniform acceleration. We consider a two-mode squeezed state of the field from an inertial perspective, and analytically study the degradation of entanglement due to the Unruh effect, in the cases of either one or both observers undergoing uniform acceleration. We find that, for two observers undergoing finite acceleration, the entanglement vanishes between the lowest-frequency modes. The loss of entanglement is precisely explained as a redistribution of the inertial entanglement into multipartite quantum correlations among accessible and inaccessible modes from a noninertial perspective. We show that classical correlations are also lost from the perspective of two accelerated observers but conserved if one of the observers remains inertial

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)

Quantum separability and entanglement detection via entanglement-witness search and global optimization

International Nuclear Information System (INIS)

Ioannou, Lawrence M.; Travaglione, Benjamin C.

2006-01-01

We focus on determining the separability of an unknown bipartite quantum state ρ by invoking a sufficiently large subset of all possible entanglement witnesses given the expected value of each element of a set of mutually orthogonal observables. We review the concept of an entanglement witness from the geometrical point of view and use this geometry to show that the set of separable states is not a polytope and to characterize the class of entanglement witnesses (observables) that detect entangled states on opposite sides of the set of separable states. All this serves to motivate a classical algorithm which, given the expected values of a subset of an orthogonal basis of observables of an otherwise unknown quantum state, searches for an entanglement witness in the span of the subset of observables. The idea of such an algorithm, which is an efficient reduction of the quantum separability problem to a global optimization problem, was introduced by [Ioannou et al., Phys. Rev. A 70, 060303(R)], where it was shown to be an improvement on the naive approach for the quantum separability problem (exhaustive search for a decomposition of the given state into a convex combination of separable states). The last section of the paper discusses in more generality such algorithms, which, in our case, assume a subroutine that computes the global maximum of a real function of several variables. Despite this, we anticipate that such algorithms will perform sufficiently well on small instances that they will render a feasible test for separability in some cases of interest (e.g., in 3x3 dimensional systems)

Two-point entanglement near a quantum phase transition

International Nuclear Information System (INIS)

Chen, Han-Dong

2007-01-01

In this work, we study the two-point entanglement S(i, j), which measures the entanglement between two separated degrees of freedom (ij) and the rest of system, near a quantum phase transition. Away from the critical point, S(i, j) saturates with a characteristic length scale ξ E , as the distance |i - j| increases. The entanglement length ξ E agrees with the correlation length. The universality and finite size scaling of entanglement are demonstrated in a class of exactly solvable one-dimensional spin model. By connecting the two-point entanglement to correlation functions in the long range limit, we argue that the prediction power of a two-point entanglement is universal as long as the two involved points are separated far enough

Entanglement dynamics in itinerant fermionic and bosonic systems

Science.gov (United States)

Pillarishetty, Durganandini

2017-04-01

The concept of quantum entanglement of identical particles is fundamental in a wide variety of quantum information contexts involving composite quantum systems. However, the role played by particle indistinguishabilty in entanglement determination is being still debated. In this work, we study, theoretically, the entanglement dynamics in some itinerant bosonic and fermionic systems. We show that the dynamical behaviour of particle entanglement and spatial or mode entanglement are in general different. We also discuss the effect of fermionic and bosonic statistics on the dynamical behaviour. We suggest that the different dynamical behaviour can be used to distinguish between particle and mode entanglement in identical particle systems and discuss possible experimental realizations for such studies. I acknowledge financial support from DST, India through research Grant.

Optimal use of multipartite entanglement for continuous variable teleportation

International Nuclear Information System (INIS)

Adesso, G.; Illuminati, F.

2005-01-01

Full text: In this work we discuss how continuous variable teleportation takes advantage of the quadrature entanglement in different ways, depending on the preparation of the entangled state. For a given amount of the entanglement resource, we describe the best production scheme for a two-mode Gaussian state, which enables quantum teleportation with optimal fidelity. We extend this study to multiparty entangled Gaussian states and define an operative measure of multipartite entanglement related to the optimal fidelity in a quantum teleportation network experiment. This optimal fidelity is shown to be equivalent to the entanglement of formation for the standard two-user protocol, and to the multipartite localizable entanglement for the multiuser protocol. (author)

Probability-density-function characterization of multipartite entanglement

International Nuclear Information System (INIS)

Facchi, P.; Florio, G.; Pascazio, S.

2006-01-01

We propose a method to characterize and quantify multipartite entanglement for pure states. The method hinges upon the study of the probability density function of bipartite entanglement and is tested on an ensemble of qubits in a variety of situations. This characterization is also compared to several measures of multipartite entanglement

Experimental determination of entanglement with a single measurement.

Science.gov (United States)

Walborn, S P; Souto Ribeiro, P H; Davidovich, L; Mintert, F; Buchleitner, A

2006-04-20

Nearly all protocols requiring shared quantum information--such as quantum teleportation or key distribution--rely on entanglement between distant parties. However, entanglement is difficult to characterize experimentally. All existing techniques for doing so, including entanglement witnesses or Bell inequalities, disclose the entanglement of some quantum states but fail for other states; therefore, they cannot provide satisfactory results in general. Such methods are fundamentally different from entanglement measures that, by definition, quantify the amount of entanglement in any state. However, these measures suffer from the severe disadvantage that they typically are not directly accessible in laboratory experiments. Here we report a linear optics experiment in which we directly observe a pure-state entanglement measure, namely concurrence. Our measurement set-up includes two copies of a quantum state: these 'twin' states are prepared in the polarization and momentum degrees of freedom of two photons, and concurrence is measured with a single, local measurement on just one of the photons.

Dynamics of entanglement under decoherence in noninertial frames

International Nuclear Information System (INIS)

Shi Jia-Dong; Wu Tao; Song Xue-Ke; Ye Liu

2014-01-01

In this paper, we investigate the entanglement dynamics of a two-qubit entangled state coupled with its noisy environment, and plan to utilize weak measurement and quantum reversal measurement to study the entanglement dynamics under different decoherence channels in noninertial frames. Through the calculations and analyses, it is shown that the weak measurement can prevent entanglement from coupling to the amplitude damping channel, while the system is under the phase damping and flip channels. This protection protocol cannot prevent entanglement but will accelerate the death of entanglement. In addition, if the system is in the noninertial reference frame, then the effect of weak measurement will be weakened for the amplitude damping channel. Nevertheless, for other decoherence channels, the Unruh effect does not affect the quantum weak measurement, the only exception is that the maximum value of entanglement is reduced to √2/2 of the original value in the inertial frames. (general)

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.

Background information and first results on eco-audits in the water management and disposal sector; Hintergruende und Erfahrungen zur Oekoauditierung im Wasser- und Entsorgungsbereich

Energy Technology Data Exchange (ETDEWEB)

Keune, H.

1996-07-01

In spite of the large number of publications on eco-auditing, there are still details that are not generally known and may come as a surprise. The author presents various aspects of auditing, e.g. the indirect effects of customers`s wishes and competitors on the incentives given by new legal regulations, on the obstacles to eco-auditing posed by European and German legislation, and the fears of auditing. (orig.) [Deutsch] Trotz einer kaum noch ueberschaubaren Zahl von Veroeffentlichungen zum Oeko-Audit gibt es immer noch Details, die nicht allgemein bekannt sind und die zuweilen sogar noch ueberraschen koennen. Der Autor geht auf verschiedene Aspekte im Zusammenhang mit der Auditierung ein: Auf den `indirekten Zwang`, der von Kunden und der Konkurrenz ausgeuebt wird, auf die Anreize durch neue gesetzliche Regelungen, auf die Huerden der Auditierung aufgrund der EU-Verordnung und des deutschen Umweltaudit-Gesetzes zusammen mit dem Verwaltungs- und Strafrecht, dem Umweltinformationsrecht und dem Recht ueber den unlauteren Wettbewerb sowie auf die Angst vor der Auditierung. (orig.)

Attack-Induced Entanglement of Noninteracting Fermi Gas

International Nuclear Information System (INIS)

Ren Jie; Zhu Shiqun

2008-01-01

The bipartite entanglement in Fermi gas without interaction is investigated when there are three fermions in the system. The negativity and the von Neumann entropy are employed to measure the entanglement of the system. The position of the third fermion can affect the entanglement between the first and the second fermions. The entanglement can be enhanced or suppressed when the third fermion changes its position. When the two fermions are at the same position or when their distance is more than 2.0/k F , the third fermion cannot affect them

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.

Anomalies of the entanglement entropy in chiral theories

Energy Technology Data Exchange (ETDEWEB)

Iqbal, Nabil [Institute for Theoretical Physics, University of Amsterdam,Science Park 904, Postbus 94485, 1090 GL Amsterdam (Netherlands); Wall, Aron C. [School of Natural Sciences, Institute for Advanced Study,Princeton, New Jersey 08540 (United States)

2016-10-20

We study entanglement entropy in theories with gravitational or mixed U(1) gauge-gravitational anomalies in two, four and six dimensions. In such theories there is an anomaly in the entanglement entropy: it depends on the choice of reference frame in which the theory is regulated. We discuss subtleties regarding regulators and entanglement entropies in anomalous theories. We then study the entanglement entropy of free chiral fermions and self-dual bosons and show that in sufficiently symmetric situations this entanglement anomaly comes from an imbalance in the flux of modes flowing through the boundary, controlled by familiar index theorems. In two and four dimensions we use anomalous Ward identities to find general expressions for the transformation of the entanglement entropy under a diffeomorphism. (In the case of a mixed anomaly there is an alternative presentation of the theory in which the entanglement entropy is not invariant under a U(1) gauge transformation. The free-field manifestation of this phenomenon involves a novel kind of fermion zero mode on a gravitational background with a twist in the normal bundle to the entangling surface.) We also study d-dimensional anomalous systems as the boundaries of d+1 dimensional gapped Hall phases. Here the full system is non-anomalous, but the boundary anomaly manifests itself in a change in the entanglement entropy when the boundary metric is sheared relative to the bulk.

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.

Quantum-entanglement storage and extraction in quantum network node

Science.gov (United States)

Shan, Zhuoyu; Zhang, Yong

Quantum computing and quantum communication have become the most popular research topic. Nitrogen-vacancy (NV) centers in diamond have been shown the great advantage of implementing quantum information processing. The generation of entanglement between NV centers represents a fundamental prerequisite for all quantum information technologies. In this paper, we propose a scheme to realize the high-fidelity storage and extraction of quantum entanglement information based on the NV centers at room temperature. We store the entangled information of a pair of entangled photons in the Bell state into the nuclear spins of two NV centers, which can make these two NV centers entangled. And then we illuminate how to extract the entangled information from NV centers to prepare on-demand entangled states for optical quantum information processing. The strategy of engineering entanglement demonstrated here maybe pave the way towards a NV center-based quantum network.

Sudden entanglement death, and ways to avoid it

International Nuclear Information System (INIS)

Eberly, J.H.; Ting Yu

2005-01-01

We report that non-communicating but entangled qubit pairs are almost universally liable to sudden entanglement death. In the presence of minor and purely local environmental noises their mixed-state entanglement may abruptly become zero long before the noises are able to destroy the local qubit coherence. Despite the inability of unitary transformations to alter entanglement, for example of Werner states, unitary transformations have been found to delay or defeat the sudden death event. These results upset the conventional understanding that entanglement lifetime can be estimated from qubit lifetime. This is not even approximately or qualitatively true. (author)

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.

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

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.)

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

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.

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.

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

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)

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)

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.

Review: Gerd Jüttemann (Hrsg. (2013. Die Entwicklung der Psyche in der Geschichte der Menschheit

Directory of Open Access Journals (Sweden)

Uwe Krebs

2015-03-01

Full Text Available Der Vorbereitungsband für die Reihe "Die Psychogenese der Menschheit" – ein Sammelband aus 32 Beiträgen, betitelt "Die Entwicklung der Psyche in der Geschichte der Menschheit" und 2013 herausgegeben von Gerd JÜTTEMANN – wird in dieser Besprechung in mehreren Schritten vorgestellt und bewertet. Zunächst wird kontextuell argumentiert, dass die bewährte, empirisch-experimentelle Methodologie der Psychologie zur Vernachlässigung weiterer Erkenntnisverfahren führte, die bei Themen wie dem hier zu besprechenden Werk allein verbleiben und die kurz angesprochen werden. Sodann wird das Werk im Überblick knapp dargestellt und die außergewöhnliche Heterogenität in Inhalten und Methoden betont. Die Besprechung einzelner Beiträge, die nach dem Gesichtspunkt großer Unterschiedlichkeit ausgewählt wurden, schließt sich an. Die abschließende Gesamtbewertung betont den lückenhaften Forschungsstand, die Notwendigkeit der allein verbleibenden qualitativen Methodik mit ihren verschiedenen Möglichkeiten und nennt Desiderata künftigen Vorgehens für diesen thematisch und methodisch interessanten Auftakt-Band, der insbesondere durch Dichte und Verschiedenheit der Beiträge beeindruckt. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1502219

Collapse–revival of quantum discord and entanglement

International Nuclear Information System (INIS)

Yan, Xue-Qun; Zhang, Bo-Ying

2014-01-01

In this paper the correlations dynamics of two atoms in the case of a micromaser-type system is investigated. Our results predict certain quasi-periodic collapse and revival phenomena for quantum discord and entanglement when the field is in Fock state and the two atoms are initially in maximally mixed state, which is a special separable state. Our calculations also show that the oscillations of the time evolution of both quantum discord and entanglement are almost in phase and they both have similar evolution behavior in some time range. The fact reveals the consistency of quantum discord and entanglement in some dynamical aspects. - Highlights: • The correlations dynamics of two atoms in the case of a micromaser-type system is investigated. • A quasi-periodic collapse and revival phenomenon for quantum discord and entanglement is reported. • A phenomenon of correlations revivals different from that of non-Markovian dynamics is revealed. • The oscillations of time evolution of both quantum discord and entanglement are almost in phase in our system. • Quantum discord and entanglement have similar evolution behavior in some time range

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 .

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)

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

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.

Breakdown of entanglement during the teleportation

International Nuclear Information System (INIS)

Wang Jinfeng; Wang Yuming; Li Xueqian

2005-01-01

The teleportation may become an important means for remote distance communications in the future, and the mechanism is based on entanglement of quantum states. But the entanglement is fragile. As the state is disturbed by the environment the entanglement may be broken down. In this work, authors choose the electron-positron pair in an entangled state of spin 0 as an example to investigate the rate of breaking down of the entanglement by the Compton scattering with the background radiation photons or Bremsstrahlung with strong magnetic fields of some astronomical objects which the electron or positron passes by. Since the spin projection of single electron (positron) is not physically measurable and the electron beams cannot keep its shape for long because of the Coulomb repulsion among the charged particles in the beam, the only way is to shoot one electron-positron pair each time and continuously repeat the processes. With all the restraints this study has only pedagogic meaning, but may shed light on further studies where other information messages are chosen. (authors)

Current problems arising from the new law relating to franchise duties; Aktuelle Probleme des neuen Konzessionsabgabenrechts

Energy Technology Data Exchange (ETDEWEB)

Becker, P.

1996-12-31

The contribution examines the advantages and drawbacks of the new ordinance in German law relating to payment of franchise duties. The ordinance may bring about new problems if abused as a means of bringing pressure to bear in negotiations for takeover of existing electric or gas supply systems by local governments. The author analyses the legitimation of such exploitation of the franchise duty and in this context the general legal framework. (orig./CB) [Deutsch] Der Beitrag untersucht Vor- und Nachteile der neuen Verordnung im Konzessionsabgabenrecht, die im Hinblick auf Auseinandersetzungen um die ``Ubernahme von Strom- oder Gasversorgungssystemen durch Gemeinden neue Probleme mit sich bringen koennte, wenn Konzessionsabgaben als Druckmittel eingesetzt werden. Der Autor analysiert die Zulaessigkeit eines derartigen Einsatzes und in diesem Zusammenhang auch die rechtliche Basis der Konzessionsabgaben. (orig./CB)

Communication of technical building systems. Fundamentals; Kommunikation technischer Gebaeudesysteme. Grundlagen

Energy Technology Data Exchange (ETDEWEB)

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

1995-12-31

In chapter 17 of the anthology about building control the communication between and with technical building systems is described. The following aspects are discussed: From the matrix cable to the standard bus, data transmission, communication terms, components of communication systems, type of data transmission, types of connection, networks, protocols, the ISO/OSI reference model, application of automation in the field of communication, services and profiles, communication objects. (BWI) [Deutsch] Kapitel 17 des Sammelbandes ueber Building Control ist dem Thema der Kommunikation zwischen und mit technischen Gebaeudesystemen gewidmet. In diesem Zusammenhang werden folgende Themen angesprochen: Vom Matrixkabel zum Standard-Bus; Daten-Transport; Kommunikations-Begriffe; Komponenten der Kommunikations-Systeme; Art der Datenuebertragung; Verbindungsarten, Netze, Protokolle; Das ISO/OSI Referenzmodell; Automation als Anwendung in der Kommunikation; Dienste und Profile; Kommunikationsobjekte. (BWI)

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.

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.

Entanglement dynamics of a pure bipartite system in dissipative environments

International Nuclear Information System (INIS)

Tahira, Rabia; Ikram, Manzoor; Azim, Tasnim; Suhail Zubairy, M

2008-01-01

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.

Erschließung der medizinhistorischen Separatasammlungen der Universitätsbibliothek der Medizinischen Universität Wien

OpenAIRE

Sabine Wallig; Judith Dögl; Isabella Seidl; Marlene Giesa

2015-01-01

Die Universitätsbibliothek der Medizinischen Universität Wien verfügt über ein wertvolles kulturhistorisches Erbe, das die Geschichte der „Wiener Medizinischen Schule“ repräsentiert. Einen Teil der in der Zweigbibliothek für Geschichte der Medizin beherbergten historischen Literatur bilden die medizinhistorischen Separatasammlungen. Diese Unikate stellen einen unschätzbaren Mehrwert als Quellenmaterial für medizinhistorische und biografische Forschungen dar. Bei den etwa 140.000 Einzele...

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.

Entangling two transportable neutral atoms via local spin exchange.

Science.gov (United States)

Kaufman, A M; Lester, B J; Foss-Feig, M; Wall, M L; Rey, A M; Regal, C A

2015-11-12

To advance quantum information science, physical systems are sought that meet the stringent requirements for creating and preserving quantum entanglement. In atomic physics, robust two-qubit entanglement is typically achieved by strong, long-range interactions in the form of either Coulomb interactions between ions or dipolar interactions between Rydberg atoms. Although such interactions allow fast quantum gates, the interacting atoms must overcome the associated coupling to the environment and cross-talk among qubits. Local interactions, such as those requiring substantial wavefunction overlap, can alleviate these detrimental effects; however, such interactions present a new challenge: to distribute entanglement, qubits must be transported, merged for interaction, and then isolated for storage and subsequent operations. Here we show how, using a mobile optical tweezer, it is possible to prepare and locally entangle two ultracold neutral atoms, and then separate them while preserving their entanglement. Ground-state neutral atom experiments have measured dynamics consistent with spin entanglement, and have detected entanglement with macroscopic observables; we are now able to demonstrate position-resolved two-particle coherence via application of a local gradient and parity measurements. This new entanglement-verification protocol could be applied to arbitrary spin-entangled states of spatially separated atoms. The local entangling operation is achieved via spin-exchange interactions, and quantum tunnelling is used to combine and separate atoms. These techniques provide a framework for dynamically entangling remote qubits via local operations within a large-scale quantum register.

„Sprache, du heilige“: Sprachreflexionen in der deutschen Dichtung der Bukowina

Directory of Open Access Journals (Sweden)

Petro Rychlo

2017-12-01

Full Text Available Der Aufsatz befasst sich mit der historischen und kulturellen Rolle der deutschen Sprache in der Bukowina, wo sie zwischen 1875 und 1918 den Status einer offiziellen Staats- und Umgangssprache hatte und sogar nach dem Zerfall der Habsburgermonarchie noch eine Zeitlang auf verschiedenen Ebenen funktionierte. Das verursachte in der Bukowina und besonders in ihrer Hauptstadt Czernowitz die Herausbildung einer deutschsprachigen Literatur, deren Anfänge in die Mitte des 19. Jahrhundert fallen. Zuerst nur als „Heimatliteratur“ begriffen, entwickelte sie sich bald, vor allem auf dem Gebiet der lyrischen Dichtung, zu einem beachtlichen literarischen Phänomen, das in der Zwischenkriegszeit im Werk solcher Dichter wie Alfred Margul-Sperber, Rose Ausländer, David Goldfeld, Alfred Kittner, Moses Rosenkranz, Immanuel Weißglas, Paul Celan, Alfred Gong, Selma Meerbaum-Eisinger ihre höchste Blüte erlebte. Infolge der fortschreitenden Romanisierung des Landes und der Bedrohung des Sprachverlusts greifen um diese Zeit viele Czernowitzer deutschjüdische Dichter öfters zur Sprachproblematik, indem sie sie in ihren Gedichten im tragischen Sinne thematisieren. Nach dem Holocaust und der Emigration aus der Bukowina verwandelt sich die Muttersprache für verbannte Dichter in ein Synonym der Heimat („Mutterland Wort“. Der Artikel analysiert Sprachreflexionen der Czernowitzer Autoren als Strategie des kulturellen und existenziellen Überlebens.

Entanglement entropy after selective measurements in quantum chains

Energy Technology Data Exchange (ETDEWEB)

Najafi, Khadijeh [Department of Physics, Georgetown University,37th and O Sts. NW, Washington, DC 20057 (United States); Rajabpour, M.A. [Instituto de Física, Universidade Federal Fluminense,Av. Gal. Milton Tavares de Souza s/n, Gragoatá, 24210-346, Niterói, RJ (Brazil)

2016-12-22

We study bipartite post measurement entanglement entropy after selective measurements in quantum chains. We first study the quantity for the critical systems that can be described by conformal field theories. We find a connection between post measurement entanglement entropy and the Casimir energy of floating objects. Then we provide formulas for the post measurement entanglement entropy for open and finite temperature systems. We also comment on the Affleck-Ludwig boundary entropy in the context of the post measurement entanglement entropy. Finally, we also provide some formulas regarding modular hamiltonians and entanglement spectrum in the after measurement systems. After through discussion regarding CFT systems we also provide some predictions regarding massive field theories. We then discuss a generic method to calculate the post measurement entanglement entropy in the free fermion systems. Using the method we study the post measurement entanglement entropy in the XY spin chain. We check numerically the CFT and the massive field theory results in the transverse field Ising chain and the XX model. In particular, we study the post meaurement entanglement entropy in the infinite, periodic and open critical transverse field Ising chain and the critical XX model. The effect of the temperature and the gap is also discussed in these models.

Entanglement entropy after selective measurements in quantum chains

International Nuclear Information System (INIS)

Najafi, Khadijeh; Rajabpour, M.A.

2016-01-01

We study bipartite post measurement entanglement entropy after selective measurements in quantum chains. We first study the quantity for the critical systems that can be described by conformal field theories. We find a connection between post measurement entanglement entropy and the Casimir energy of floating objects. Then we provide formulas for the post measurement entanglement entropy for open and finite temperature systems. We also comment on the Affleck-Ludwig boundary entropy in the context of the post measurement entanglement entropy. Finally, we also provide some formulas regarding modular hamiltonians and entanglement spectrum in the after measurement systems. After through discussion regarding CFT systems we also provide some predictions regarding massive field theories. We then discuss a generic method to calculate the post measurement entanglement entropy in the free fermion systems. Using the method we study the post measurement entanglement entropy in the XY spin chain. We check numerically the CFT and the massive field theory results in the transverse field Ising chain and the XX model. In particular, we study the post meaurement entanglement entropy in the infinite, periodic and open critical transverse field Ising chain and the critical XX model. The effect of the temperature and the gap is also discussed in these models.

Entanglement between noncomplementary parts of many-body systems

International Nuclear Information System (INIS)

Wichterich, Hannu Christian

2011-01-01

This thesis investigates the structure and behaviour of entanglement, the purely quantum mechanical part of correlations, in many-body systems, employing both numerical and analytical techniques at the interface of condensed matter theory and quantum information theory. Entanglement can be seen as a precious resource which, for example, enables the noiseless and instant transmission of quantum information, provided the communicating parties share a sufficient ''amount'' of it. Furthermore, measures of entanglement of a quantum mechanical state are perceived as useful probes of collective properties of many-body systems. For instance, certain measures are capable of detecting and classifying ground-state phases and, particularly, transition (or critical) points separating such phases. Chapters 2 and 3 focus on entanglement in many-body systems and its use as a potential resource for communication protocols. They address the questions of how a substantial amount of entanglement can be established between distant subsystems, and how efficiently this entanglement could be ''harvested'' by way of measurements. The subsequent chapters 4 and 5 are devoted to universality of entanglement between large collections of particles undergoing a quantum phase transition, where, despite the enormous complexity of these systems, collective properties including entanglement no longer depend crucially on the microscopic details. (orig.)

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

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

Entanglement entropy evolution under double-trace deformation

Energy Technology Data Exchange (ETDEWEB)

Song, Yushu [College of Physical Science and Technology, Hebei University, Baoding (China)

2017-12-15

In this paper, we study the bulk entanglement entropy evolution in conical BTZ black bole background using the heat kernel method. This is motivated by exploring the new examples where the quantum correction of the entanglement entropy gives the leading contribution. We find that in the large black hole limit the bulk entanglement entropy decreases under the double-trace deformation which is consistent with the holographic c theorem and in the small black hole limit the bulk entanglement entropy increases under the deformation. We also discuss the minimal area correction. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Entanglement entropy and differential entropy for massive flavors

International Nuclear Information System (INIS)

Jones, Peter A.R.; Taylor, Marika

2015-01-01

In this paper we compute the holographic entanglement entropy for massive flavors in the D3-D7 system, for arbitrary mass and various entangling region geometries. We show that the universal terms in the entanglement entropy exactly match those computed in the dual theory using conformal perturbation theory. We derive holographically the universal terms in the entanglement entropy for a CFT perturbed by a relevant operator, up to second order in the coupling; our results are valid for any entangling region geometry. We present a new method for computing the entanglement entropy of any top-down brane probe system using Kaluza-Klein holography and illustrate our results with massive flavors at finite density. Finally we discuss the differential entropy for brane probe systems, emphasising that the differential entropy captures only the effective lower-dimensional Einstein metric rather than the ten-dimensional geometry.

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.

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.

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

Separability criteria and method of measurement for entanglement

Science.gov (United States)

Mohd, Siti Munirah; Idrus, Bahari; Mukhtar, Muriati

2014-06-01

Quantum computers have the potentials to solve certain problems faster than classical computers. In quantum computer, entanglement is one of the elements beside superposition. Recently, with the advent of quantum information theory, entanglement has become an important resource for Quantum Information and Computation. The purpose of this paper is to discuss the separability criteria and method of measurement for entanglement. This paper is aimed at viewing the method that has been proposed in previous works in bipartite and multipartite entanglement. The outcome of this paper is to classify the different method that used to measure entanglement for bipartite and multipartite cases including the advantage and disadvantage of each method.

Separability criteria and method of measurement for entanglement

Energy Technology Data Exchange (ETDEWEB)

Mohd, Siti Munirah; Idrus, Bahari; Mukhtar, Muriati [Industrial Computing Research Group, Faculty of Information Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

2014-06-19

Quantum computers have the potentials to solve certain problems faster than classical computers. In quantum computer, entanglement is one of the elements beside superposition. Recently, with the advent of quantum information theory, entanglement has become an important resource for Quantum Information and Computation. The purpose of this paper is to discuss the separability criteria and method of measurement for entanglement. This paper is aimed at viewing the method that has been proposed in previous works in bipartite and multipartite entanglement. The outcome of this paper is to classify the different method that used to measure entanglement for bipartite and multipartite cases including the advantage and disadvantage of each method.

Non-Markovian dynamics of entanglement for multipartite systems

Energy Technology Data Exchange (ETDEWEB)

Zhou Jiang; Wu Chengjun; Zhu Mingyi; Guo Hong, E-mail: hongguo@pku.edu.c [CREAM Group, State Key Laboratory of Advanced Optical Communication Systems and Networks (Peking University) and Institute of Quantum Electronics, School of Electronics Engineering and Computer Science, and Center for Computational Science and Engineering (CCSE), Peking University, Beijing 100871 (China)

2009-11-14

Entanglement dynamics for a couple of two-level atoms interacting with independent structured reservoirs is studied using a non-perturbative approach. It is shown that the revival of atom entanglement is not necessarily accompanied by the sudden death of reservoir entanglement, and vice versa. In fact, atom entanglement can revive before, simultaneously or even after the disentanglement of reservoirs. Using a novel method based on the population analysis for the excited atomic state, we present the quantitative criteria for the revival and death phenomena. To give a more physically intuitive insight, the quasimode Hamiltonian method is applied. Our quantitative analysis is helpful for the practical engineering of entanglement.

Characterizing entanglement with global and marginal entropic measures

International Nuclear Information System (INIS)

Adesso, Gerardo; Illuminati, Fabrizio; De Siena, Silvio

2003-01-01

We qualify the entanglement of arbitrary mixed states of bipartite quantum systems by comparing global and marginal mixednesses quantified by different entropic measures. For systems of two qubits we discriminate the class of maximally entangled states with fixed marginal mixednesses, and determine an analytical upper bound relating the entanglement of formation to the marginal linear entropies. This result partially generalizes to mixed states the quantification of entanglement with marginal mixednesses holding for pure states. We identify a class of entangled states that, for fixed marginals, are globally more mixed than product states when measured by the linear entropy. Such states cannot be discriminated by the majorization criterion

Entanglement-assisted quantum MDS codes from negacyclic codes

Science.gov (United States)

Lu, Liangdong; Li, Ruihu; Guo, Luobin; Ma, Yuena; Liu, Yang

2018-03-01

The entanglement-assisted formalism generalizes the standard stabilizer formalism, which can transform arbitrary classical linear codes into entanglement-assisted quantum error-correcting codes (EAQECCs) by using pre-shared entanglement between the sender and the receiver. In this work, we construct six classes of q-ary entanglement-assisted quantum MDS (EAQMDS) codes based on classical negacyclic MDS codes by exploiting two or more pre-shared maximally entangled states. We show that two of these six classes q-ary EAQMDS have minimum distance more larger than q+1. Most of these q-ary EAQMDS codes are new in the sense that their parameters are not covered by the codes available in the literature.

Separability criteria and method of measurement for entanglement

International Nuclear Information System (INIS)

Mohd, Siti Munirah; Idrus, Bahari; Mukhtar, Muriati

2014-01-01

Quantum computers have the potentials to solve certain problems faster than classical computers. In quantum computer, entanglement is one of the elements beside superposition. Recently, with the advent of quantum information theory, entanglement has become an important resource for Quantum Information and Computation. The purpose of this paper is to discuss the separability criteria and method of measurement for entanglement. This paper is aimed at viewing the method that has been proposed in previous works in bipartite and multipartite entanglement. The outcome of this paper is to classify the different method that used to measure entanglement for bipartite and multipartite cases including the advantage and disadvantage of each method

Quantifying entanglement in two-mode Gaussian states

Science.gov (United States)

Tserkis, Spyros; Ralph, Timothy C.

2017-12-01

Entangled two-mode Gaussian states are a key resource for quantum information technologies such as teleportation, quantum cryptography, and quantum computation, so quantification of Gaussian entanglement is an important problem. Entanglement of formation is unanimously considered a proper measure of quantum correlations, but for arbitrary two-mode Gaussian states no analytical form is currently known. In contrast, logarithmic negativity is a measure that is straightforward to calculate and so has been adopted by most researchers, even though it is a less faithful quantifier. In this work, we derive an analytical lower bound for entanglement of formation of generic two-mode Gaussian states, which becomes tight for symmetric states and for states with balanced correlations. We define simple expressions for entanglement of formation in physically relevant situations and use these to illustrate the problematic behavior of logarithmic negativity, which can lead to spurious conclusions.

Entanglement of identical particles and the detection process

DEFF Research Database (Denmark)

Tichy, Malte C.; de Melo, Fernando; Kus, Marek

2013-01-01

We introduce detector-level entanglement, a unified entanglement concept for identical particles that takes into account the possible deletion of many-particle which-way information through the detection process. The concept implies a measure for the effective indistinguishability of the particles...... statistical behavior depends on their initial entanglement. Our results show that entanglement cannot be attributed to a state of identical particles alone, but that the detection process has to be incorporated in the analysis....

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)

Distillable entanglement in d circle times d dimensions

NARCIS (Netherlands)

Hamieh, S; Zaraket, H

2003-01-01

Distillable entanglement (E-d) is one of the acceptable measures of entanglement of mixed states. On the basis of discrimination through local operation and classical communication, this letter gives E-d for two classes of orthogonal multipartite maximally entangled states.

Effect of Bound Entanglement on the Convertibility of Pure States

International Nuclear Information System (INIS)

Ishizaka, Satoshi

2004-01-01

I show that bound entanglement strongly influences the quantum entanglement processing of pure states: If N distant parties share appropriate bound entangled states with positive partial transpose, all N-partite pure entangled states become inter-convertible by stochastic local operations and classical communication (SLOCC) at the single copy level. This implies that the Schmidt rank of a bipartite pure entangled state can be increased, and that two incomparable tripartite entanglement of the GHZ and W type can be inter-converted by the assistance of bound entanglement. Further, I propose the simplest experimental scheme for the demonstration of the corresponding bound-entanglement-assisted SLOCC. This scheme does not need quantum gates and is feasible for the current experimental technology of linear optics

Entanglement sharing via qudit channels: Nonmaximally entangled states may be necessary for one-shot optimal singlet fraction and negativity

Science.gov (United States)

Pal, Rajarshi; Bandyopadhyay, Somshubhro

2018-03-01

We consider the problem of establishing entangled states of optimal singlet fraction and negativity between two remote parties for every use of a noisy quantum channel and trace-preserving local operations and classical communication (LOCC) under the assumption that the parties do not share prior correlations. We show that for a family of quantum channels in every finite dimension d ≥3 , one-shot optimal singlet fraction and entanglement negativity are attained only with appropriate nonmaximally entangled states. A consequence of our results is that the ordering of entangled states in all finite dimensions may not be preserved under trace-preserving LOCC.

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...

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

Effect of mode–mode competition on atom–atom entanglement

International Nuclear Information System (INIS)

Qin, Wu; Mao-Fa, Fang; Jian-Wu, Cai

2010-01-01

A system consisting of two atoms interacting with a two-mode vacuum is considered, where each atom is resonant with the two cavity modes through two different competing transitions. The effect of mode–mode competition on the atom–atom entanglement is investigated. We find that the entanglement between the two atoms can be induced by the mode–mode competition. For the initial atomic state |Ψ(0)}, whether the atoms are initially separated or entangled, a large or even maximal entanglement between them can be obtained periodically by introducing the mode–mode competition. For the initial atomic state |Φ(0)}, the strong mode–mode competition can prevent the two atoms entangled initially from suffering entanglement sudden death; besides, it makes them in a more stable and longer-lived entanglement than in the non-competition case. (classical areas of phenomenology)

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.

Der Einsatz von medizinischen Trainingszentren für die Ausbildung zum Arzt in Deutschland, Österreich und der deutschsprachigen Schweiz [Clinical Skills Labs in Medical Education in Germany, Austria and German Speaking Switzerland

Directory of Open Access Journals (Sweden)

Schmidt, Anita

2008-05-01

. Die Fragen zu Personalkosten, laufenden Kosten und Anschaffungskosten wurden nur von sehr wenigen Zentren und sehr inhomogen beantwortet. Diskussion: Die Einrichtung von Medizinischen Trainingszentren im deutschsprachigen Raum ist durch die neue ÄAppO und durch die Erhebung von Studiengebühren deutlich vorangetrieben worden. Große Ähnlichkeiten zwischen den Zentren zeigten sich in den Bereichen Lehrinhalte, -methoden und Prüfungen. Es fand sich keine Korrelation zwischen der Größe des Trainingszentrums und seinem Gründungszeitpunkt oder den Anschaffungs- bzw. Personalkosten. Der deutliche Anstieg von neu eröffneten TZ in zeitlichem Zusammenhang mit der Einführung der Studiengebühren legt nahe, dass hiermit eine konkrete Verbesserung der Ausbildungssituation durch die Studiengebühren beabsichtigt wird. Schlussfolgerung: Um Ressourcen zu sparen, wird eine enge Zusammenarbeit der bestehenden Trainingszentren und eventuell die Entwicklung gemeinsamer Qualitätsstandards oder einer Leitlinie für medizinische Trainingszentren empfohlen. Auch erscheint eine genaue Klärung des Begriffes “zentrales Trainingszentrum“ notwendig. Als Plattform für eine solche Zusammenarbeit empfehlen die Autoren den .

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.

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.

Cryotherapy for rheumatic diseases; Kryotherapie bei rheumatischen Erkrankungen

Energy Technology Data Exchange (ETDEWEB)

Soerensen, H. [Rheumaklinik Immanuel-Krankenhaus, Berlin (Germany)

1994-12-31

Coldtherapy (cryotherapy) is a subdiscipline of thermotherapy. A distinction can be made between local forms of cryotherapy and whole-body cryotherapy. This paper presents the cold room of the Immanuel Hospital in Berlin-Wannsee. It deals in particular with the cold-generation equipment: air conduction, air exchange, humidity, room temperature, control. (BWI) [Deutsch] Die Kaeltetherapie (Kryotherapie) ist ein Teilgebiet der Thermotherapie. Es wird dabei zwischen lokalen Kaeltetherapien und Ganzkoerperkaeltetherapie unterschieden. Der vorliegende Beitrag stellt die Kaeltekammer des Immanuel-Krankenhauses in Berlin-Wannsee vor. In diesem Zusammenhang werden insbesonder die Kaelteanlagen dargestellt: Luftfuehrung, Luftwechsel, Luftfeuchte, Raumtemperatur, Steuerung. (BWI)

Right, laws, regulations and technical building systems; Recht, Gesetze, Verordnungen und Technische Gebaeudesysteme

Energy Technology Data Exchange (ETDEWEB)

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

1995-12-31

Chapter 23 of the anthology about building control gives an overview of the laws and regulations in the field of technical building systems. The following fields are discussed: license regulations in the field of building trade, communication law, environmental responsibility law, building right, European directives, laws and regulations of the Federal Government and the Laender. (BWI) [Deutsch] Kapitel 23 des Sammelbandes ueber Building Control gibt einen Ueberblick ueber Recht, Gesetze und Verordnungen im Bereich der Technischen Gebaeudesysteme. In diesem Zusammenhang kommen folgende Bereiche in Frage: Lizenzrecht im Bauwesen; Fernmelderecht; Umwelthaftungsgesetz; Baurecht; Europaeische Richtlinien; Gesetze und Verordnungen des Bundes und der Laender. (BWI)

Digital announcements from data carrier exchange to telecommunication; Digitale Ausschreibungen; vom Datentraegeraustausch zur Telekommunikation

Energy Technology Data Exchange (ETDEWEB)

Markert, H. [MW Software GmbH, Koeln (Germany)

1995-12-31

In chapter 7 of the anthology about building control digital announcements are described ranging from data carrier exchange to telecommunication. The following aspects are discussed: Exchange of texts and prices as well of service lists and offers, telecommunication software, costs of communication, comparison of paper, disk and telecommunication. (BWI) [Deutsch] Kapitel 7 des Sammelbandes ueber Building Control ist dem Thema der digitalen Ausschreibung gewidmet, reichend vom Datentraegeraustausch zur Telekommunikation. In diesem Zusammenhang wird auf folgende Themen eingegangen: Austausch von Texten und Preisen sowie von Leistungsverzeichnissen und Angeboten; Telekommunikations-Software; Kosten der Kommunikation sowie Vergleich Papier - Diskette - Telekommunikation. (BWI)

Continuous-variable entanglement distillation of non-Gaussian mixed states

International Nuclear Information System (INIS)

Dong Ruifang; Lassen, Mikael; Heersink, Joel; Marquardt, Christoph; Leuchs, Gerd; Filip, Radim; Andersen, Ulrik L.

2010-01-01

Many different quantum-information communication protocols such as teleportation, dense coding, and entanglement-based quantum key distribution are based on the faithful transmission of entanglement between distant location in an optical network. The distribution of entanglement in such a network is, however, hampered by loss and noise that is inherent in all practical quantum channels. Thus, to enable faithful transmission one must resort to the protocol of entanglement distillation. In this paper we present a detailed theoretical analysis and an experimental realization of continuous variable entanglement distillation in a channel that is inflicted by different kinds of non-Gaussian noise. The continuous variable entangled states are generated by exploiting the third order nonlinearity in optical fibers, and the states are sent through a free-space laboratory channel in which the losses are altered to simulate a free-space atmospheric channel with varying losses. We use linear optical components, homodyne measurements, and classical communication to distill the entanglement, and we find that by using this method the entanglement can be probabilistically increased for some specific non-Gaussian noise channels.

Generalized Remote Preparation of Arbitrary m-qubit Entangled States via Genuine Entanglements

Directory of Open Access Journals (Sweden)

Dong Wang

2015-03-01

Full Text Available Herein, we present a feasible, general protocol for quantum communication within a network via generalized remote preparation of an arbitrary m-qubit entangled state designed with genuine tripartite Greenberger–Horne–Zeilinger-type entangled resources. During the implementations, we construct novel collective unitary operations; these operations are tasked with performing the necessary phase transfers during remote state preparations. We have distilled our implementation methods into a five-step procedure, which can be used to faithfully recover the desired state during transfer. Compared to previous existing schemes, our methodology features a greatly increased success probability. After the consumption of auxiliary qubits and the performance of collective unitary operations, the probability of successful state transfer is increased four-fold and eight-fold for arbitrary two- and three-qubit entanglements when compared to other methods within the literature, respectively. We conclude this paper with a discussion of the presented scheme for state preparation, including: success probabilities, reducibility and generalizability.

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.

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

Entanglement Evolution of Three-Qubit States under Local Decoherence

International Nuclear Information System (INIS)

Ma Xiaosan; Liu Gaosheng; Wang Anmin

2010-01-01

By using negativity as entanglement measure, we have investigated the effect of local decoherence from a non-Markovian environment on the time evolution of entanglement of three-qubit states including the GHZ state, the W state, and the Werner state. From the results, we find that the entanglement dynamics depends not only on the coupling strengths but also on the specific states of concern. Specifically, the entanglement takes different behaviors under weak or strong coupling and it varies with the quantum states under study. The entanglement of the GHZ state and the Werner state can be destroyed completely by the local decoherence, while the entanglement of the W state can survive through the local decoherence partially. (general)

Bound entangled states violate a nonsymmetric local uncertainty relation

International Nuclear Information System (INIS)

Hofmann, Holger F.

2003-01-01

As a consequence of having a positive partial transpose, bound entangled states lack many of the properties otherwise associated with entanglement. It is therefore interesting to identify properties that distinguish bound entangled states from separable states. In this paper, it is shown that some bound entangled states violate a nonsymmetric class of local uncertainty relations [H. F. Hofmann and S. Takeuchi, Phys. Rev. A 68, 032103 (2003)]. This result indicates that the asymmetry of nonclassical correlations may be a characteristic feature of bound entanglement

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.

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

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)