Li, Qian; Zhu, Changhua; Ma, Shuquan; Wei, Kejin; Pei, Changxing
2018-04-01
Measurement-device-independent quantum key distribution (MDI-QKD) is immune to all detector side-channel attacks. However, practical implementations of MDI-QKD, which require two-photon interferences from separated independent single-photon sources and a nontrivial reference alignment procedure, are still challenging with current technologies. Here, we propose a scheme that significantly reduces the experimental complexity of two-photon interferences and eliminates reference frame alignment by the combination of plug-and-play and reference frame independent MDI-QKD. Simulation results show that the secure communication distance can be up to 219 km in the finite-data case and the scheme has good potential for practical MDI-QKD systems.
Brown, Matthew J.
2014-02-01
The framework of quantum frames can help unravel some of the interpretive difficulties i the foundation of quantum mechanics. In this paper, I begin by tracing the origins of this concept in Bohr's discussion of quantum theory and his theory of complementarity. Engaging with various interpreters and followers of Bohr, I argue that the correct account of quantum frames must be extended beyond literal space-time reference frames to frames defined by relations between a quantum system and the exosystem or external physical frame, of which measurement contexts are a particularly important example. This approach provides superior solutions to key EPR-type measurement and locality paradoxes.
Zhuo-Dan, Zhu; Shang-Hong, Zhao; Chen, Dong; Ying, Sun
2018-07-01
In this paper, a phase-encoded measurement device independent quantum key distribution (MDI-QKD) protocol without a shared reference frame is presented, which can generate secure keys between two parties while the quantum channel or interferometer introduces an unknown and slowly time-varying phase. The corresponding secret key rate and single photons bit error rate is analysed, respectively, with single photons source (SPS) and weak coherent source (WCS), taking finite-key analysis into account. The numerical simulations show that the modified phase-encoded MDI-QKD protocol has apparent superiority both in maximal secure transmission distance and key generation rate while possessing the improved robustness and practical security in the high-speed case. Moreover, the rejection of the frame-calibrating part will intrinsically reduce the consumption of resources as well as the potential security flaws of practical MDI-QKD systems.
Device-dependent and device-independent quantum key distribution without a shared reference frame
International Nuclear Information System (INIS)
Slater, Joshua A; Tittel, Wolfgang; Branciard, Cyril; Brunner, Nicolas
2014-01-01
Standard quantum key distribution (QKD) protocols typically assume that the distant parties share a common reference frame. In practice, however, establishing and maintaining a good alignment between distant observers is rarely a trivial issue, which may significantly restrain the implementation of long-distance quantum communication protocols. Here we propose simple QKD protocols that do not require the parties to share any reference frame, and study their security and feasibility in both the usual device-dependent (DD) case—in which the two parties use well characterized measurement devices—as well as in the device-independent (DI) case—in which the measurement devices can be untrusted, and the security relies on the violation of a Bell inequality. To illustrate the practical relevance of these ideas, we present a proof-of-principle demonstration of our protocols using polarization entangled photons distributed over a coiled 10-km long optical fiber. We consider two situations, in which either the fiber spool's polarization transformation freely drifts, or randomly chosen polarization transformations are applied. The correlations obtained from measurements allow, with high probability, to generate positive asymptotic secret key rates in both the DD and DI scenarios (under the fair-sampling assumption for the latter case). (paper)
Demonstration of free-space reference frame independent quantum key distribution
International Nuclear Information System (INIS)
Wabnig, J; Bitauld, D; Li, H W; Niskanen, A O; Laing, A; O'Brien, J L
2013-01-01
Quantum key distribution (QKD) is moving from research laboratories towards applications. As computing becomes more mobile, cashless as well as cardless payment solutions are introduced. A possible route to increase the security of wireless communications is to incorporate QKD in a mobile device. Handheld devices present a particular challenge as the orientation and the phase of a qubit will depend on device motion. This problem is addressed by the reference frame independent (RFI) QKD scheme. The scheme tolerates an unknown phase between logical states that vary slowly compared to the rate of particle repetition. Here we experimentally demonstrate the feasibility of RFI QKD over a free-space link in a prepare and measure scheme using polarization encoding. We extend the security analysis of the RFI QKD scheme to be able to deal with uncalibrated devices and a finite number of measurements. Together these advances are an important step towards mass production of handheld QKD devices. (paper)
Changing quantum reference frames
Palmer, Matthew C.; Girelli, Florian; Bartlett, Stephen D.
2013-01-01
We consider the process of changing reference frames in the case where the reference frames are quantum systems. We find that, as part of this process, decoherence is necessarily induced on any quantum system described relative to these frames. We explore this process with examples involving reference frames for phase and orientation. Quantifying the effect of changing quantum reference frames serves as a first step in developing a relativity principle for theories in which all objects includ...
International Nuclear Information System (INIS)
Kaufherr, T.
1981-01-01
The idea that only relative variables have physical meaning came to be known as Mach's principle. Carrying over this idea to quantum theory, has led to the consideration of finite mass, macroscopic reference frames, relative to which all physical quantities are measured. During the process of measurement, a finite mass observer receives a kickback, and this reaction of the measuring device is not negligible in quantum theory because of the quantization of the action. Hence, the observer himself has to be included in the system that is being considered. Using this as the starting point, a number of thought experiments involving finite mass observers is discussed which have quantum uncertainties in their time or in their position. These thought experiments serve to elucidate in a qualitative way some of the difficulties involved, as well as pointing out a direction to take in seeking solutions to them. When the discussion is extended to include more than one observer, the question of the covariance of the theory immediately arises. Because none of the frames of reference should be preferred, the theory should be covariant. This demand expresses an equivalence principle which here is extended to include reference frames which are in quantum uncertainties relative to each other. Formulating the problem in terms of canonical variables, the ensueing free Hamiltonian contains vector and scalar potentials which represent the kick that the reference frame receives during measurement. These are essentially gravitational type potentials, resulting, as it were, from the extension of the equivalence principle into the quantum domain
Quantum reference frames and quantum transformations
International Nuclear Information System (INIS)
Toller, M.
1997-01-01
A quantum frame is defined by a material object following the laws of quantum mechanics. The present paper studies the relations between quantum frames, which are described by some generalization of the Poincare' group. The possibility of using a suitable quantum group is examined, but some arguments are given which show that a different mathematical structure is necessary. Some simple examples in lower-dimensional space-times are treated. They indicate the necessity of taking into account some ''internal'' degrees of freedom of the quantum frames, that can be disregarded in a classical treatment
Quantum independent increment processes
Franz, Uwe
2006-01-01
This is the second of two volumes containing the revised and completed notes of lectures given at the school "Quantum Independent Increment Processes: Structure and Applications to Physics". This school was held at the Alfried-Krupp-Wissenschaftskolleg in Greifswald in March, 2003, and supported by the Volkswagen Foundation. The school gave an introduction to current research on quantum independent increment processes aimed at graduate students and non-specialists working in classical and quantum probability, operator algebras, and mathematical physics. The present second volume contains the following lectures: "Random Walks on Finite Quantum Groups" by Uwe Franz and Rolf Gohm, "Quantum Markov Processes and Applications in Physics" by Burkhard Kümmerer, Classical and Free Infinite Divisibility and Lévy Processes" by Ole E. Barndorff-Nielsen, Steen Thorbjornsen, and "Lévy Processes on Quantum Groups and Dual Groups" by Uwe Franz.
Quantum independent increment processes
Franz, Uwe
2005-01-01
This volume is the first of two volumes containing the revised and completed notes lectures given at the school "Quantum Independent Increment Processes: Structure and Applications to Physics". This school was held at the Alfried-Krupp-Wissenschaftskolleg in Greifswald during the period March 9 – 22, 2003, and supported by the Volkswagen Foundation. The school gave an introduction to current research on quantum independent increment processes aimed at graduate students and non-specialists working in classical and quantum probability, operator algebras, and mathematical physics. The present first volume contains the following lectures: "Lévy Processes in Euclidean Spaces and Groups" by David Applebaum, "Locally Compact Quantum Groups" by Johan Kustermans, "Quantum Stochastic Analysis" by J. Martin Lindsay, and "Dilations, Cocycles and Product Systems" by B.V. Rajarama Bhat.
Quantum communication, reference frames, and gauge theory
International Nuclear Information System (INIS)
Enk, S. J. van
2006-01-01
We consider quantum communication in the case that the communicating parties not only do not share a reference frame but use imperfect quantum communication channels, in that each channel applies some fixed but unknown unitary rotation to each qubit. We discuss similarities and differences between reference frames within that quantum communication model and gauge fields in gauge theory. We generalize the concept of refbits and analyze various quantum communication protocols within the communication model
Logical independence and quantum randomness
International Nuclear Information System (INIS)
Paterek, T; Kofler, J; Aspelmeyer, M; Zeilinger, A; Brukner, C; Prevedel, R; Klimek, P
2010-01-01
We propose a link between logical independence and quantum physics. We demonstrate that quantum systems in the eigenstates of Pauli group operators are capable of encoding mathematical axioms and show that Pauli group quantum measurements are capable of revealing whether or not a given proposition is logically dependent on the axiomatic system. Whenever a mathematical proposition is logically independent of the axioms encoded in the measured state, the measurement associated with the proposition gives random outcomes. This allows for an experimental test of logical independence. Conversely, it also allows for an explanation of the probabilities of random outcomes observed in Pauli group measurements from logical independence without invoking quantum theory. The axiomatic systems we study can be completed and are therefore not subject to Goedel's incompleteness theorem.
Logical independence and quantum randomness
Energy Technology Data Exchange (ETDEWEB)
Paterek, T; Kofler, J; Aspelmeyer, M; Zeilinger, A; Brukner, C [Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences, Boltzmanngasse 3, A-1090 Vienna (Austria); Prevedel, R; Klimek, P [Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna (Austria)], E-mail: tomasz.paterek@univie.ac.at
2010-01-15
We propose a link between logical independence and quantum physics. We demonstrate that quantum systems in the eigenstates of Pauli group operators are capable of encoding mathematical axioms and show that Pauli group quantum measurements are capable of revealing whether or not a given proposition is logically dependent on the axiomatic system. Whenever a mathematical proposition is logically independent of the axioms encoded in the measured state, the measurement associated with the proposition gives random outcomes. This allows for an experimental test of logical independence. Conversely, it also allows for an explanation of the probabilities of random outcomes observed in Pauli group measurements from logical independence without invoking quantum theory. The axiomatic systems we study can be completed and are therefore not subject to Goedel's incompleteness theorem.
Time reversibility in the quantum frame
Energy Technology Data Exchange (ETDEWEB)
Masot-Conde, Fátima [Escuela Superior Ingenieros, Dpt. Física Aplicada III, Universidad de Sevilla Isla Mágica, 41092- Sevilla (Spain)
2014-12-04
Classic Mechanics and Electromagnetism, conventionally taken as time-reversible, share the same concept of motion (either of mass or charge) as the basis of the time reversibility in their own fields. This paper focuses on the relationship between mobile geometry and motion reversibility. The goal is to extrapolate the conclusions to the quantum frame, where matter and radiation behave just as elementary mobiles. The possibility that the asymmetry of Time (Time’s arrow) is an effect of a fundamental quantum asymmetry of elementary particles, turns out to be a consequence of the discussion.
Relativistic quantum games in noninertial frames
Energy Technology Data Exchange (ETDEWEB)
Khan, Salman; Khan, M Khalid, E-mail: sksafi@phys.qau.edu.pk [Department of Physics, Quaid-i-Azam University, Islamabad 45320 (Pakistan)
2011-09-02
We study the influence of the Unruh effect on quantum non-zero sum games. In particular, we investigate the quantum Prisoners' Dilemma both for entangled and unentangled initial states and show that the acceleration of the noninertial frames disturbs the symmetry of the game. It is shown that for the maximally entangled initial state, the classical strategy C-hat (cooperation) becomes the dominant strategy. Our investigation shows that any quantum strategy does no better for any player against the classical strategies. The miracle move of Eisert et al (1999 Phys. Rev. Lett.83 3077) is no more a superior move. We show that the dilemma-like situation is resolved in favor of one player or the other. (paper)
Relativistic quantum games in noninertial frames
International Nuclear Information System (INIS)
Khan, Salman; Khan, M Khalid
2011-01-01
We study the influence of the Unruh effect on quantum non-zero sum games. In particular, we investigate the quantum Prisoners' Dilemma both for entangled and unentangled initial states and show that the acceleration of the noninertial frames disturbs the symmetry of the game. It is shown that for the maximally entangled initial state, the classical strategy C-hat (cooperation) becomes the dominant strategy. Our investigation shows that any quantum strategy does no better for any player against the classical strategies. The miracle move of Eisert et al (1999 Phys. Rev. Lett.83 3077) is no more a superior move. We show that the dilemma-like situation is resolved in favor of one player or the other. (paper)
The Role of Frame Force in Quantum Detection
National Research Council Canada - National Science Library
Benedetto, John J; Kebo, Andrew
2007-01-01
.... In this paper, we focus on a quantum detection problem, where the goal is to construct a tight frame that minimizes an error term, which in quantum physics has the interpretation of the probability of a detection error...
Investigating learners' epistemological framings of quantum mechanics
Dini, Vesal
Classical mechanics challenges students to use their intuitions and experiences as a basis for understanding, in effect to approach learning as "a refinement of everyday thinking'' (Einstein, 1936). Moving on to quantum mechanics (QM), students, like physicists, need to adjust this approach, in particular with respect to the roles that intuitive knowledge and mathematics play in the pursuit of coherent understanding (these are adjustments to aspects of their epistemologies). In this dissertation, I explore how some students manage the epistemological transition. I began this work by recruiting both graduate and undergraduate students, interviewing each subject several times as they moved through coursework in QM. The interviews featured, among other things, how students tried to fit ideas together in mutually consistent ways, including with respect to intuitive knowledge, mathematics and experiment, if at all. I modeled these dynamic cognitive processes as different epistemological framings (i.e., tacit, in-the-moment responses to the question "How should I approach knowledge?''). Through detailed qualitative analyses of students' reasoning and a systematic coding of their interviews, I explored how these coherence seeking related framings impacted their learning. The dissertation supports three main findings: (1) students' patterns of epistemological framing are mostly stable within a given course; (2) students who profess epistemologies aligned with the coordination of coherence seeking framings tend to be more stable in demonstrating them; and (3) students aware that their understanding of QM ultimately anchors in its mathematics tend to produce more coherent explanations and perform better in their courses. These findings are consistent with existing research on student epistemologies in QM and imply that epistemologies, in particular whether and how students seek coherence, require greater attention and emphasis in instruction.
Students' Epistemological Framing in Quantum Mechanics Problem Solving
Modir, Bahar; Thompson, John D.; Sayre, Eleanor C.
2017-01-01
Students' difficulties in quantum mechanics may be the result of unproductive framing and not a fundamental inability to solve the problems or misconceptions about physics content. We observed groups of students solving quantum mechanics problems in an upper-division physics course. Using the lens of epistemological framing, we investigated four…
Reciprocal relativity of noninertial frames: quantum mechanics
Energy Technology Data Exchange (ETDEWEB)
Low, Stephen G [4301 Avenue D, Austin, Texas, 78751 (United States)
2007-04-06
Noninertial transformations on time-position-momentum-energy space {l_brace}t, q, p, e{r_brace} with invariant Born-Green metric ds{sup 2} = -dt{sup 2} + 1/c{sup 2} dq{sup 2} + 1/b{sup 2} (dp{sup 2} = 1/c{sup 2} de{sup 2}) and the symplectic metric -de and dt + dp and dq are studied. This U 1,3) group of transformations contains the Lorentz group as the inertial special case and, in the limit of small forces and velocities, reduces to the expected Hamilton transformations leaving invariant the symplectic metric and the nonrelativistic line element ds{sup 2} -dt{sup 2}. The U(1,3) transformations bound relative velocities by c and relative forces by b. Spacetime is no longer an invariant subspace but is relative to noninertial observer frames. In the limit of b {yields} {infinity}, spacetime is invariant. Born was lead to the metric by a concept of reciprocity between position and momentum degrees of freedom and for this reason we call this reciprocal relativity. For large b, such effects will almost certainly only manifest in a quantum regime. Wigner showed that special relativistic quantum mechanics follows from the projective representations of the inhomogeneous Lorentz group. Projective representations of a Lie group are equivalent to the unitary representations of its central extension. The same method of projective representations for the inhomogeneous U(1,3) group is used to define the quantum theory in the noninertial case. The central extension of the inhomogeneous U(1,3) group is the cover of the quaplectic group Q(1,3) U(1,3) x{sub s} H(4), H(4) is the Weyl-Heisenberg group. The H(4) group, and the associated Heisenberg commutation relations central to quantum mechanics, results directly from requiring projective representations. A set of second-order wave equations result from the representations of the Casimir operators.
Quantum mechanics with respect to different reference frames
International Nuclear Information System (INIS)
Mangiarotti, L.; Sardanashvily, G.
2007-01-01
Geometric (Schroedinger) quantization of nonrelativistic mechanics with respect to different reference frames is considered. In classical nonrelativistic mechanics, a reference frame is represented by a connection on a configuration space fibered over a time axis R. Under quantization, it yields a connection on the quantum algebra of Schroedinger operators. The operators of energy with respect to different reference frames are examined
Quantum cryptography: The power of independence
Ekert, Artur
2018-02-01
Device-independent quantum cryptography promises unprecedented security, but it is regarded as a theorist's dream and an experimentalist's nightmare. A new mathematical tool has now pushed its experimental demonstration much closer to reality.
Quantum bit commitment with misaligned reference frames
International Nuclear Information System (INIS)
Harrow, Aram; Oliveira, Roberto; Terhal, Barbara M.
2006-01-01
Suppose that Alice and Bob define their coordinate axes differently, and the change of reference frame between them is given by a probability distribution μ over SO(3). We show that this uncertainty of reference frame is of no use for bit commitment when μ is uniformly distributed over a (sub)group of SO(3), but other choices of μ can give rise to a partially or even arbitrarily secure bit commitment
Tight Reference Frame–Independent Quantum Teleportation
Directory of Open Access Journals (Sweden)
Dominic Verdon
2017-01-01
Full Text Available We give a tight scheme for teleporting a quantum state between two parties whose reference frames are misaligned by an action of a finite symmetry group. Unlike previously proposed schemes, ours requires no additional tokens or data to be passed between the participants; the same amount of classical information is transferred as for ordinary quantum teleportation, and the Hilbert space of the entangled resource is of the same size. In the terminology of Peres and Scudo, our protocol relies on classical communication of unspeakable information.
Open quantum systems in noninertial frames
International Nuclear Information System (INIS)
Khan, Salman; Khan, M K
2011-01-01
We study the effects of decoherence on the entanglement generated by the Unruh effect in noninertial frames by using phase flip, phase damping and depolarizing channels. It is shown that decoherence strongly influences the initial state entanglement. Entanglement sudden death can occur irrespective of the acceleration of the noninertial frame under the action of phase flip and phase damping channels. It is investigated that an early sudden death occurs for large acceleration under the depolarizing environment. Moreover, entanglement increases for a highly decohered phase flip channel.
Parallel Device-Independent Quantum Key Distribution
Jain, Rahul; Miller, Carl A.; Shi, Yaoyun
2017-01-01
A prominent application of quantum cryptography is the distribution of cryptographic keys with unconditional security. Recently, such security was extended by Vazirani and Vidick (Physical Review Letters, 113, 140501, 2014) to the device-independent (DI) scenario, where the users do not need to trust the integrity of the underlying quantum devices. The protocols analyzed by them and by subsequent authors all require a sequential execution of N multiplayer games, where N is the security parame...
Fully Device-Independent Quantum Key Distribution
Vazirani, Umesh; Vidick, Thomas
2014-10-01
Quantum cryptography promises levels of security that are impossible to replicate in a classical world. Can this security be guaranteed even when the quantum devices on which the protocol relies are untrusted? This central question dates back to the early 1990s when the challenge of achieving device-independent quantum key distribution was first formulated. We answer this challenge by rigorously proving the device-independent security of a slight variant of Ekert's original entanglement-based protocol against the most general (coherent) attacks. The resulting protocol is robust: While assuming only that the devices can be modeled by the laws of quantum mechanics and are spatially isolated from each other and from any adversary's laboratory, it achieves a linear key rate and tolerates a constant noise rate in the devices. In particular, the devices may have quantum memory and share arbitrary quantum correlations with the eavesdropper. The proof of security is based on a new quantitative understanding of the monogamous nature of quantum correlations in the context of a multiparty protocol.
The resource theory of quantum reference frames: manipulations and monotones
International Nuclear Information System (INIS)
Gour, Gilad; Spekkens, Robert W
2008-01-01
Every restriction on quantum operations defines a resource theory, determining how quantum states that cannot be prepared under the restriction may be manipulated and used to circumvent the restriction. A superselection rule (SSR) is a restriction that arises through the lack of a classical reference frame and the states that circumvent it (the resource) are quantum reference frames. We consider the resource theories that arise from three types of SSRs, associated respectively with lacking: (i) a phase reference, (ii) a frame for chirality, and (iii) a frame for spatial orientation. Focusing on pure unipartite quantum states (and in some cases restricting our attention even further to subsets of these), we explore single-copy and asymptotic manipulations. In particular, we identify the necessary and sufficient conditions for a deterministic transformation between two resource states to be possible and, when these conditions are not met, the maximum probability with which the transformation can be achieved. We also determine when a particular transformation can be achieved reversibly in the limit of arbitrarily many copies and find the maximum rate of conversion. A comparison of the three resource theories demonstrates that the extent to which resources can be interconverted decreases as the strength of the restriction increases. Along the way, we introduce several measures of frameness and prove that these are monotonically non-increasing under various classes of operations that are permitted by the SSR
Measuring the quality of a quantum reference frame: The relative entropy of frameness
International Nuclear Information System (INIS)
Gour, Gilad; Marvian, Iman; Spekkens, Robert W.
2009-01-01
In the absence of a reference frame for transformations associated with group G, any quantum state that is noninvariant under the action of G may serve as a token of the missing reference frame. We here present a measure of the quality of such a token: the relative entropy of frameness. This is defined as the relative entropy distance between the state of interest and the nearest G-invariant state. Unlike the relative entropy of entanglement, this quantity is straightforward to calculate, and we find it to be precisely equal to the G-asymmetry, a measure of frameness introduced by Vaccaro et al. It is shown to provide an upper bound on the mutual information between the group element encoded into the token and the group element that may be extracted from it by measurement. In this sense, it quantifies the extent to which the token successfully simulates a full reference frame. We also show that despite a suggestive analogy from entanglement theory, the regularized relative entropy of frameness is zero and therefore does not quantify the rate of interconversion between the token and some standard form of quantum reference frame. Finally, we show how these investigations yield an approach to bounding the relative entropy of entanglement.
Quantum background independence in string theory
International Nuclear Information System (INIS)
Witten, E.
1994-01-01
Not only in physical string theories, but also in some highly simplified situations, background independence has been difficult to understand. It is argued that the ''holomorphic anomaly'' of Bershadsky, Cecotti, Ooguri and Vafa gives a fundamental explanation of some of the problems. Moreover, their anomaly equation can be interpreted in terms of a rather peculiar quantum version of background independence: in systems afflicted by the anomaly, background independence does not hold order by order in perturbation theory, but the exact partition function as a function of the coupling constants has a background independent interpretation as a state in an auxiliary quantum Hilbert space. The significance of this auxiliary space is otherwise unknown. (author). 23 refs
Measurement-device-independent quantum digital signatures
Puthoor, Ittoop Vergheese; Amiri, Ryan; Wallden, Petros; Curty, Marcos; Andersson, Erika
2016-08-01
Digital signatures play an important role in software distribution, modern communication, and financial transactions, where it is important to detect forgery and tampering. Signatures are a cryptographic technique for validating the authenticity and integrity of messages, software, or digital documents. The security of currently used classical schemes relies on computational assumptions. Quantum digital signatures (QDS), on the other hand, provide information-theoretic security based on the laws of quantum physics. Recent work on QDS Amiri et al., Phys. Rev. A 93, 032325 (2016);, 10.1103/PhysRevA.93.032325 Yin, Fu, and Zeng-Bing, Phys. Rev. A 93, 032316 (2016), 10.1103/PhysRevA.93.032316 shows that such schemes do not require trusted quantum channels and are unconditionally secure against general coherent attacks. However, in practical QDS, just as in quantum key distribution (QKD), the detectors can be subjected to side-channel attacks, which can make the actual implementations insecure. Motivated by the idea of measurement-device-independent quantum key distribution (MDI-QKD), we present a measurement-device-independent QDS (MDI-QDS) scheme, which is secure against all detector side-channel attacks. Based on the rapid development of practical MDI-QKD, our MDI-QDS protocol could also be experimentally implemented, since it requires a similar experimental setup.
Measurement device-independent quantum dialogue
Maitra, Arpita
2017-12-01
Very recently, the experimental demonstration of quantum secure direct communication (QSDC) with state-of-the-art atomic quantum memory has been reported (Zhang et al. in Phys Rev Lett 118:220501, 2017). Quantum dialogue (QD) falls under QSDC where the secrete messages are communicated simultaneously between two legitimate parties. The successful experimental demonstration of QSDC opens up the possibilities for practical implementation of QD protocols. Thus, it is necessary to analyze the practical security issues of QD protocols for future implementation. Since the very first proposal for QD by Nguyen (Phys Lett A 328:6-10, 2004), a large number of variants and extensions have been presented till date. However, all of those leak half of the secret bits to the adversary through classical communications of the measurement results. In this direction, motivated by the idea of Lo et al. (Phys Rev Lett 108:130503, 2012), we propose a measurement device-independent quantum dialogue scheme which is resistant to such information leakage as well as side-channel attacks. In the proposed protocol, Alice and Bob, two legitimate parties, are allowed to prepare the states only. The states are measured by an untrusted third party who may himself behave as an adversary. We show that our protocol is secure under this adversarial model. The current protocol does not require any quantum memory, and thus, it is inherently robust against memory attacks. Such robustness might not be guaranteed in the QSDC protocol with quantum memory (Zhang et al. 2017).
Skotiniotis, Michael
Quantum information theory is concerned with the storage, transmission, and manipulation of information that is represented in the degrees of freedom of quantum systems. These degrees of freedom are described relative to an external frame of reference. The lack of a requisite frame of reference imposes restrictions on the types of states quantum systems can be prepared in and the type of operations that can be performed on quantum systems. This thesis is concerned with the communication between two parties that lack a shared frame of reference. Specifically, I introduce a protocol whereby the parties can align their respective frames of reference, and a protocol for communicating quantum information in a reference frame independent manner. Using the accessible information to quantify the success of a reference frame alignment protocol I propose a new measure—the alignment rate—for quantifying the ability of a quantum state to stand in place of a classical frame of reference. I show that for the case where Alice and Bob lack a shared frame of reference associated with the groups G = U(1) and G = ZM (the finite cyclic group of M elements), the alignment rate is equal to the regularized, linearized G-asymmetry. The latter is a unique measure of the frameness of a quantum state and my result provides an operational interpretation of the G-asymmetry that was thus far lacking. In addition, I show that the alignment rate for finite cyclic groups of more than three elements is super-additive under the tensor product of two distinct pure quantum states. The latter is, to my knowledge, the first instance of a regularized quantity that exhibits super-additivity. In addition, I propose a reference-frame-independent protocol for communicating quantum information in the absence of a shared frame of reference associated with a general finite group G. The protocol transmits m logical qudits using r + m physical qudits prepared in a specific state that is reference-frame
Quantum reference frames and their applications to thermodynamics.
Popescu, Sandu; Sainz, Ana Belén; Short, Anthony J; Winter, Andreas
2018-07-13
We construct a quantum reference frame, which can be used to approximately implement arbitrary unitary transformations on a system in the presence of any number of extensive conserved quantities, by absorbing any back action provided by the conservation laws. Thus, the reference frame at the same time acts as a battery for the conserved quantities. Our construction features a physically intuitive, clear and implementation-friendly realization. Indeed, the reference system is composed of the same types of subsystems as the original system and is finite for any desired accuracy. In addition, the interaction with the reference frame can be broken down into two-body terms coupling the system to one of the reference frame subsystems at a time. We apply this construction to quantum thermodynamic set-ups with multiple, possibly non-commuting conserved quantities, which allows for the definition of explicit batteries in such cases.This article is part of a discussion meeting issue 'Foundations of quantum mechanics and their impact on contemporary society'. © 2018 The Author(s).
Frame transforms, star products and quantum mechanics on phase space
International Nuclear Information System (INIS)
Aniello, P; Marmo, G; Man'ko, V I
2008-01-01
Using the notions of frame transform and of square integrable projective representation of a locally compact group G, we introduce a class of isometries (tight frame transforms) from the space of Hilbert-Schmidt operators in the carrier Hilbert space of the representation into the space of square integrable functions on the direct product group G x G. These transforms have remarkable properties. In particular, their ranges are reproducing kernel Hilbert spaces endowed with a suitable 'star product' which mimics, at the level of functions, the original product of operators. A 'phase space formulation' of quantum mechanics relying on the frame transforms introduced in the present paper, and the link of these maps with both the Wigner transform and the wavelet transform are discussed
Source-Independent Quantum Random Number Generation
Cao, Zhu; Zhou, Hongyi; Yuan, Xiao; Ma, Xiongfeng
2016-01-01
Quantum random number generators can provide genuine randomness by appealing to the fundamental principles of quantum mechanics. In general, a physical generator contains two parts—a randomness source and its readout. The source is essential to the quality of the resulting random numbers; hence, it needs to be carefully calibrated and modeled to achieve information-theoretical provable randomness. However, in practice, the source is a complicated physical system, such as a light source or an atomic ensemble, and any deviations in the real-life implementation from the theoretical model may affect the randomness of the output. To close this gap, we propose a source-independent scheme for quantum random number generation in which output randomness can be certified, even when the source is uncharacterized and untrusted. In our randomness analysis, we make no assumptions about the dimension of the source. For instance, multiphoton emissions are allowed in optical implementations. Our analysis takes into account the finite-key effect with the composable security definition. In the limit of large data size, the length of the input random seed is exponentially small compared to that of the output random bit. In addition, by modifying a quantum key distribution system, we experimentally demonstrate our scheme and achieve a randomness generation rate of over 5 ×103 bit /s .
Source-Independent Quantum Random Number Generation
Directory of Open Access Journals (Sweden)
Zhu Cao
2016-02-01
Full Text Available Quantum random number generators can provide genuine randomness by appealing to the fundamental principles of quantum mechanics. In general, a physical generator contains two parts—a randomness source and its readout. The source is essential to the quality of the resulting random numbers; hence, it needs to be carefully calibrated and modeled to achieve information-theoretical provable randomness. However, in practice, the source is a complicated physical system, such as a light source or an atomic ensemble, and any deviations in the real-life implementation from the theoretical model may affect the randomness of the output. To close this gap, we propose a source-independent scheme for quantum random number generation in which output randomness can be certified, even when the source is uncharacterized and untrusted. In our randomness analysis, we make no assumptions about the dimension of the source. For instance, multiphoton emissions are allowed in optical implementations. Our analysis takes into account the finite-key effect with the composable security definition. In the limit of large data size, the length of the input random seed is exponentially small compared to that of the output random bit. In addition, by modifying a quantum key distribution system, we experimentally demonstrate our scheme and achieve a randomness generation rate of over 5×10^{3} bit/s.
Quantum cosmology with effects of a preferred reference frame
International Nuclear Information System (INIS)
Ghaffarnejad, Hossein
2010-01-01
Recently, we presented a gravity model by generalizing the Brans-Dicke theory which is suitable for studying the metric signature transition dynamics without using an imaginary time parameter. Adding a suitable scalar potential described in terms of the Brans-Dicke scalar field 'Φ-tilde, this alternative theory is used to study the Wheeler-DeWitt approach of quantum cosmology. We assumed that the universe is defined in a flat Robertson-Walker metric with Lorentzian signature. In that case, the Wheeler-DeWitt wavefunctional is obtained as two-dimensional quantum harmonic oscillator convergent polynomials for both of the choices of positive and negative values of the Brans-Dicke parameter. Here we choose a preferred reference frame with a time coordinate of 'γ' which relates to time of cosmological free falling observer 't' as 'dt= Φ-tilde(γ)dγ'.
Measurement-Device-Independent Quantum Cryptography
Tang, Zhiyuan
Quantum key distribution (QKD) enables two legitimate parties to share a secret key even in the presence of an eavesdropper. The unconditional security of QKD is based on the fundamental laws of quantum physics. Original security proofs of QKD are based on a few assumptions, e.g., perfect single photon sources and perfect single-photon detectors. However, practical implementations of QKD systems do not fully comply with such assumptions due to technical limitations. The gap between theory and implementations leads to security loopholes in most QKD systems, and several attacks have been launched on sophisticated QKD systems. Particularly, the detectors have been found to be the most vulnerable part of QKD. Much effort has been put to build side-channel-free QKD systems. Solutions such as security patches and device-independent QKD have been proposed. However, the former are normally ad-hoc, and cannot close unidentified loopholes. The latter, while having the advantages of removing all assumptions on devices, is impractical to implement today. Measurement-device-independent QKD (MDI-QKD) turns out to be a promising solution to the security problem of QKD. In MDI-QKD, all security loopholes, including those yet-to-be discovered, have been removed from the detectors, the most critical part in QKD. In this thesis, we investigate issues related to the practical implementation and security of MDI-QKD. We first present a demonstration of polarization-encoding MDI-QKD. Taking finite key effect into account, we achieve a secret key rate of 0.005 bit per second (bps) over 10 km spooled telecom fiber, and a 1600-bit key is distributed. This work, together with other demonstrations, shows the practicality of MDI-QKD. Next we investigate a critical assumption of MDI-QKD: perfect state preparation. We apply the loss-tolerant QKD protocol and adapt it to MDI-QKD to quantify information leakage due to imperfect state preparation. We then present an experimental demonstration of
Fault-tolerant quantum computing in the Pauli or Clifford frame with slow error diagnostics
Directory of Open Access Journals (Sweden)
Christopher Chamberland
2018-01-01
Full Text Available We consider the problem of fault-tolerant quantum computation in the presence of slow error diagnostics, either caused by measurement latencies or slow decoding algorithms. Our scheme offers a few improvements over previously existing solutions, for instance it does not require active error correction and results in a reduced error-correction overhead when error diagnostics is much slower than the gate time. In addition, we adapt our protocol to cases where the underlying error correction strategy chooses the optimal correction amongst all Clifford gates instead of the usual Pauli gates. The resulting Clifford frame protocol is of independent interest as it can increase error thresholds and could find applications in other areas of quantum computation.
Proof-of-concept of real-world quantum key distribution with quantum frames
International Nuclear Information System (INIS)
Lucio-Martinez, I; Mo, X; Tittel, W; Chan, P; Hosier, S
2009-01-01
We propose a fibre-based quantum key distribution system, which employs polarization qubits encoded into faint laser pulses. As a novel feature, it allows sending of classical framing information via sequences of strong laser pulses that precede the quantum data. This allows synchronization, sender and receiver identification and compensation of time-varying birefringence in the communication channel. In addition, this method also provides a platform to communicate implementation specific information such as encoding and protocol in view of future optical quantum networks. We demonstrate in a long-term (37 h) proof-of-principle study that polarization information encoded in the classical control frames can indeed be used to stabilize unwanted qubit transformation in the quantum channel. All optical elements in our setup can be operated at Gbps rates, which is a first requirement for a future system delivering secret keys at Mbps. In order to remove another bottleneck towards a high rate system, we investigate forward error correction based on low-density parity-check codes.
Some aspects of transformation of the nonlinear plasma equations to the space-independent frame
International Nuclear Information System (INIS)
Paul, S.N.; Chakraborty, B.
1982-01-01
Relativistically correct transformation of nonlinear plasma equations are derived in a space-independent frame. This transformation is useful in many ways because in place of partial differential equations one obtains a set of ordinary differential equations in a single independent variable. Equations of Akhiezer and Polovin (1956) for nonlinear plasma oscillations have been generalized and the results of Arons and Max (1974), and others for wave number shift and precessional rotation of electromagnetic wave are recovered in a space-independent frame. (author)
Practical device-independent quantum cryptography via entropy accumulation.
Arnon-Friedman, Rotem; Dupuis, Frédéric; Fawzi, Omar; Renner, Renato; Vidick, Thomas
2018-01-31
Device-independent cryptography goes beyond conventional quantum cryptography by providing security that holds independently of the quality of the underlying physical devices. Device-independent protocols are based on the quantum phenomena of non-locality and the violation of Bell inequalities. This high level of security could so far only be established under conditions which are not achievable experimentally. Here we present a property of entropy, termed "entropy accumulation", which asserts that the total amount of entropy of a large system is the sum of its parts. We use this property to prove the security of cryptographic protocols, including device-independent quantum key distribution, while achieving essentially optimal parameters. Recent experimental progress, which enabled loophole-free Bell tests, suggests that the achieved parameters are technologically accessible. Our work hence provides the theoretical groundwork for experimental demonstrations of device-independent cryptography.
DEFF Research Database (Denmark)
Giacobello, Daniele; Murthi, Manohar N.; Christensen, Mads Græsbøll
2010-01-01
In this paper, we describe a new approach to cope with packet loss in speech coders. The idea is to split the information present in each speech packet into two components, one to independently decode the given speech frame and one to enhance it by exploiting interframe dependencies. The scheme...... is based on sparse linear prediction and a redeﬁnition of the analysis-by-synthesis process. We present Mean Opinion Scores for the presented coder with different degrees of packet loss and show that it performs similarly to frame dependent coders for low packet loss probability and similarly to frame...
Quantum ring in a rotating frame in the presence of a topological defect
International Nuclear Information System (INIS)
Dantas, L.; Furtado, C.; Silva Netto, A.L.
2015-01-01
In this contribution, we study the effects caused by rotation of an electron/hole in the presence of a screw dislocation confined in a quantum ring potential, within a quantum dynamics. The Tan–Inkson potential is used to model the confinement of the particle in two-dimensional quantum ring. We suppose that the quantum ring is placed in the presence of an external uniform magnetic field and an Aharonov–Bohm flux in the center of the system, and that the frame rotates around the z-axis. The Schrödinger equation is solved and the eigenfunctions and energy eigenvalues are exactly obtained for this configuration. The influence of the dislocation and the rotation on both the persistent current and magnetization is also studied. - Highlights: • Quantum ring in a rotating frame. • Tan–Inkson potential in the presence of rotation. • Quantum ring in the presence of screw dislocation. • Landau levels
International Nuclear Information System (INIS)
Ferrie, Christopher; Emerson, Joseph
2008-01-01
Several finite-dimensional quasi-probability representations of quantum states have been proposed to study various problems in quantum information theory and quantum foundations. These representations are often defined only on restricted dimensions and their physical significance in contexts such as drawing quantum-classical comparisons is limited by the non-uniqueness of the particular representation. Here we show how the mathematical theory of frames provides a unified formalism which accommodates all known quasi-probability representations of finite-dimensional quantum systems. Moreover, we show that any quasi-probability representation is equivalent to a frame representation and then prove that any such representation of quantum mechanics must exhibit either negativity or a deformed probability calculus. (fast track communication)
Device-independent quantum key distribution secure against collective attacks
International Nuclear Information System (INIS)
Pironio, Stefano; Gisin, Nicolas; AcIn, Antonio; Brunner, Nicolas; Massar, Serge; Scarani, Valerio
2009-01-01
Device-independent quantum key distribution (DIQKD) represents a relaxation of the security assumptions made in usual quantum key distribution (QKD). As in usual QKD, the security of DIQKD follows from the laws of quantum physics, but contrary to usual QKD, it does not rely on any assumptions about the internal working of the quantum devices used in the protocol. In this paper, we present in detail the security proof for a DIQKD protocol introduced in AcIn et al (2008 Phys. Rev. Lett. 98 230501). This proof exploits the full structure of quantum theory (as opposed to other proofs that exploit only the no-signaling principle), but only holds against collective attacks, where the eavesdropper is assumed to act on the quantum systems of the honest parties independently and identically in each round of the protocol (although she can act coherently on her systems at any time). The security of any DIQKD protocol necessarily relies on the violation of a Bell inequality. We discuss the issue of loopholes in Bell experiments in this context.
Optimal Classical Simulation of State-Independent Quantum Contextuality
Cabello, Adán; Gu, Mile; Gühne, Otfried; Xu, Zhen-Peng
2018-03-01
Simulating quantum contextuality with classical systems requires memory. A fundamental yet open question is what is the minimum memory needed and, therefore, the precise sense in which quantum systems outperform classical ones. Here, we make rigorous the notion of classically simulating quantum state-independent contextuality (QSIC) in the case of a single quantum system submitted to an infinite sequence of measurements randomly chosen from a finite QSIC set. We obtain the minimum memory needed to simulate arbitrary QSIC sets via classical systems under the assumption that the simulation should not contain any oracular information. In particular, we show that, while classically simulating two qubits tested with the Peres-Mermin set requires log224 ≈4.585 bits, simulating a single qutrit tested with the Yu-Oh set requires, at least, 5.740 bits.
Measurement-device-independent quantum communication with an untrusted source
Xu, Feihu
2015-07-01
Measurement-device-independent quantum key distribution (MDI-QKD) can provide enhanced security compared to traditional QKD, and it constitutes an important framework for a quantum network with an untrusted network server. Still, a key assumption in MDI-QKD is that the sources are trusted. We propose here a MDI quantum network with a single untrusted source. We have derived a complete proof of the unconditional security of MDI-QKD with an untrusted source. Using simulations, we have considered various real-life imperfections in its implementation, and the simulation results show that MDI-QKD with an untrusted source provides a key generation rate that is close to the rate of initial MDI-QKD in the asymptotic setting. Our work proves the feasibility of the realization of a quantum network. The network users need only low-cost modulation devices, and they can share both an expensive detector and a complicated laser provided by an untrusted network server.
Memory-assisted measurement-device-independent quantum key distribution
Panayi, Christiana; Razavi, Mohsen; Ma, Xiongfeng; Lütkenhaus, Norbert
2014-04-01
A protocol with the potential of beating the existing distance records for conventional quantum key distribution (QKD) systems is proposed. It borrows ideas from quantum repeaters by using memories in the middle of the link, and that of measurement-device-independent QKD, which only requires optical source equipment at the user's end. For certain memories with short access times, our scheme allows a higher repetition rate than that of quantum repeaters with single-mode memories, thereby requiring lower coherence times. By accounting for various sources of nonideality, such as memory decoherence, dark counts, misalignment errors, and background noise, as well as timing issues with memories, we develop a mathematical framework within which we can compare QKD systems with and without memories. In particular, we show that with the state-of-the-art technology for quantum memories, it is potentially possible to devise memory-assisted QKD systems that, at certain distances of practical interest, outperform current QKD implementations.
The Device-Independent Outlook On Quantum Physics
International Nuclear Information System (INIS)
Scarani, V.
2012-01-01
This text is an introduction to an operational outlook on Bell inequalities, which has been very fruitful in the past few years. It has lead to the recognition that Bell tests have their own place in applied quantum technologies, because they quantify non-classicality in a device-independent way, that is, without any need to describe the degrees of freedom under study and the measurements that are performed. At the more fundamental level, the same device-independent outlook has allowed the falsification of several other alternative models that could hope to reproduce the observed statistics while keeping some classical features that quantum theory denies; and it has shed new light on the long-standing quest for deriving quantum theory from physical principles. (author)
Robustness and device independence of verifiable blind quantum computing
International Nuclear Information System (INIS)
Gheorghiu, Alexandru; Kashefi, Elham; Wallden, Petros
2015-01-01
Recent advances in theoretical and experimental quantum computing bring us closer to scalable quantum computing devices. This makes the need for protocols that verify the correct functionality of quantum operations timely and has led to the field of quantum verification. In this paper we address key challenges to make quantum verification protocols applicable to experimental implementations. We prove the robustness of the single server verifiable universal blind quantum computing protocol of Fitzsimons and Kashefi (2012 arXiv:1203.5217) in the most general scenario. This includes the case where the purification of the deviated input state is in the hands of an adversarial server. The proved robustness property allows the composition of this protocol with a device-independent state tomography protocol that we give, which is based on the rigidity of CHSH games as proposed by Reichardt et al (2013 Nature 496 456–60). The resulting composite protocol has lower round complexity for the verification of entangled quantum servers with a classical verifier and, as we show, can be made fault tolerant. (paper)
Graviton propagator from background-independent quantum gravity.
Rovelli, Carlo
2006-10-13
We study the graviton propagator in Euclidean loop quantum gravity. We use spin foam, boundary-amplitude, and group-field-theory techniques. We compute a component of the propagator to first order, under some approximations, obtaining the correct large-distance behavior. This indicates a way for deriving conventional spacetime quantities from a background-independent theory.
State-independent quantum contextuality for continuous variables
International Nuclear Information System (INIS)
Plastino, Angel R.; Cabello, Adan
2010-01-01
Recent experiments have shown that nature violates noncontextual inequalities regardless of the state of the physical system. So far, all these inequalities involve measurements of dichotomic observables. We show that state-independent quantum contextuality can also be observed in the correlations between measurements of observables with genuinely continuous spectra, highlighting the universal character of the effect.
Energy Technology Data Exchange (ETDEWEB)
Shit, Anindita [Department of Chemistry, Bengal Engineering and Science University, Shibpur, Howrah 711103 (India); Chattopadhyay, Sudip, E-mail: sudip_chattopadhyay@rediffmail.com [Department of Chemistry, Bengal Engineering and Science University, Shibpur, Howrah 711103 (India); Ray Chaudhuri, Jyotipratim, E-mail: jprc_8@yahoo.com [Department of Physics, Katwa College, Katwa, Burdwan 713130 (India)
2014-03-18
Highlights: • Nonadiabatic dynamics of quantum particle under the impact of high-frequency force. • Formulation of time-independent dynamics via Floquet and Kapitza schemes. • Manipulation of external force parameters allows us to control the escape rate. • Increase of (amplitudes/frequency) causes the system to decay faster, in general. • Crossover temperature increases in the presence of the field. - Abstract: Escape under the action of the external modulation constitutes a nontrivial generalization of an conventional Kramers rate because the system is away from thermal equilibrium. A derivation of this result from the point of view of Langevin dynamics in the frame of Floquet theorem in conjunction with the Kapitza–Landau time window (that leads to an attractive description of the time-dependent quantum dynamics in terms of time-independent one) has been provided. The quantum escape rate in the intermediate-to-high and very-high damping regime so obtained analytically using the phase space formalism associated with the Wigner distribution and path-integral formalism bears a quantum correction that depends strongly on the barrier height. It is shown that an increase of (amplitude/frequency) ratio causes the system to decay faster, in general. The crossover temperature between tunneling and thermal activation increases in the presence of field so that quantum effects in the escape are relevant at higher temperatures.
Investigating Learners' Epistemological Framings of Quantum Mechanics
Dini, Vesal
2017-01-01
Classical mechanics challenges students to use their intuitions and experiences as a basis for understanding, in effect to approach learning as "a refinement of everyday thinking'' (Einstein, 1936). Moving on to quantum mechanics (QM), students, like physicists, need to adjust this approach, in particular with respect to the roles that…
International Nuclear Information System (INIS)
Ingraham, R.L.
1985-01-01
The well-known relativistic transformation law of quantum fields satisfies the relativity principle, which asserts the complete equivalence of all Lorentz (inertial) frames as far as physical measurements go. We point out a slight generalization which is allowed by the relativity principle, but violates a further, tacit assumption usually made in connection with it but which is actually logically independent of it and subject to a feasible experimental test. The interest of the generalization is that it permits the incorporation of an ultraviolet cutoff in a simple, direct way which avoids the usual difficulties
International Nuclear Information System (INIS)
Zanzi, Andrea
2010-01-01
The chameleonic behavior of the string theory dilaton is suggested. Some of the possible consequences of the chameleonic string dilaton are analyzed in detail. In particular, (1) we suggest a new stringy solution to the cosmological constant problem and (2) we point out the nonequivalence of different conformal frames at the quantum level. In order to obtain these results, we start taking into account the (strong coupling) string loop expansion in the string frame (S-frame), therefore the so-called form factors are present in the effective action. The correct dark energy scale is recovered in the Einstein frame (E-frame) without unnatural fine-tunings and this result is robust against all quantum corrections, granted that we assume a proper structure of the S-frame form factors in the strong coupling regime. At this stage, the possibility still exists that a certain amount of fine-tuning may be required to satisfy some phenomenological constraints. Moreover in the E-frame, in our proposal, all the interactions are switched off on cosmological length scales (i.e., the theory is IR-free), while higher derivative gravitational terms might be present locally (on short distances) and it remains to be seen whether these facts clash with phenomenology. A detailed phenomenological analysis is definitely necessary to clarify these points.
International Nuclear Information System (INIS)
Klink, W.H.; Wickramasekara, S.
2014-01-01
In previous work we have developed a formulation of quantum mechanics in non-inertial reference frames. This formulation is grounded in a class of unitary cocycle representations of what we have called the Galilean line group, the generalization of the Galilei group that includes transformations amongst non-inertial reference frames. These representations show that in quantum mechanics, just as is the case in classical mechanics, the transformations to accelerating reference frames give rise to fictitious forces. A special feature of these previously constructed representations is that they all respect the non-relativistic equivalence principle, wherein the fictitious forces associated with linear acceleration can equivalently be described by gravitational forces. In this paper we exhibit a large class of cocycle representations of the Galilean line group that violate the equivalence principle. Nevertheless the classical mechanics analogue of these cocycle representations all respect the equivalence principle. -- Highlights: •A formulation of Galilean quantum mechanics in non-inertial reference frames is given. •The key concept is the Galilean line group, an infinite dimensional group. •A large class of general cocycle representations of the Galilean line group is constructed. •These representations show violations of the equivalence principle at the quantum level. •At the classical limit, no violations of the equivalence principle are detected
Effective time-independent analysis for quantum kicked systems
Bandyopadhyay, Jayendra N.; Guha Sarkar, Tapomoy
2015-03-01
We present a mapping of potentially chaotic time-dependent quantum kicked systems to an equivalent approximate effective time-independent scenario, whereby the system is rendered integrable. The time evolution is factorized into an initial kick, followed by an evolution dictated by a time-independent Hamiltonian and a final kick. This method is applied to the kicked top model. The effective time-independent Hamiltonian thus obtained does not suffer from spurious divergences encountered if the traditional Baker-Cambell-Hausdorff treatment is used. The quasienergy spectrum of the Floquet operator is found to be in excellent agreement with the energy levels of the effective Hamiltonian for a wide range of system parameters. The density of states for the effective system exhibits sharp peaklike features, pointing towards quantum criticality. The dynamics in the classical limit of the integrable effective Hamiltonian shows remarkable agreement with the nonintegrable map corresponding to the actual time-dependent system in the nonchaotic regime. This suggests that the effective Hamiltonian serves as a substitute for the actual system in the nonchaotic regime at both the quantum and classical level.
Is physics in the infinite momentum frame independent of the compactificaction radius?
International Nuclear Information System (INIS)
Gueijosa, A.
1998-01-01
With the aim of clarifying the eleven-dimensional content of matrix theory, we examine the dependence of a theory in the infinite momentum frame (IMF) on the (purely spatial) longitudinal compactification radius R. It is shown that in a point particle theory the generic scattering amplitude becomes independent of R in the IMF. Processes with zero longitudinal momentum transfer are found to be exceptional. The same question is addressed in a theory with extended objects. A one-loop type II string amplitude is shown to be R-independent in the IMF, and to coincide with that of the uncompactified theory. No exceptional processes exist in this case. The possible implications of these results for M theory are discussed. In particular, if amplitudes in M theory are independent of R in the IMF, matrix theory can be rightfully expected (in the N→∞ limit) to describe uncompactified M theory. (orig.)
Framing anomaly in the effective theory of the fractional quantum Hall effect.
Gromov, Andrey; Cho, Gil Young; You, Yizhi; Abanov, Alexander G; Fradkin, Eduardo
2015-01-09
We consider the geometric part of the effective action for the fractional quantum Hall effect (FQHE). It is shown that accounting for the framing anomaly of the quantum Chern-Simons theory is essential to obtain the correct gravitational linear response functions. In the lowest order in gradients, the linear response generating functional includes Chern-Simons, Wen-Zee, and gravitational Chern-Simons terms. The latter term has a contribution from the framing anomaly which fixes the value of thermal Hall conductivity and contributes to the Hall viscosity of the FQH states on a sphere. We also discuss the effects of the framing anomaly on linear responses for non-Abelian FQH states.
Memory attacks on device-independent quantum cryptography.
Barrett, Jonathan; Colbeck, Roger; Kent, Adrian
2013-01-04
Device-independent quantum cryptographic schemes aim to guarantee security to users based only on the output statistics of any components used, and without the need to verify their internal functionality. Since this would protect users against untrustworthy or incompetent manufacturers, sabotage, or device degradation, this idea has excited much interest, and many device-independent schemes have been proposed. Here we identify a critical weakness of device-independent protocols that rely on public communication between secure laboratories. Untrusted devices may record their inputs and outputs and reveal information about them via publicly discussed outputs during later runs. Reusing devices thus compromises the security of a protocol and risks leaking secret data. Possible defenses include securely destroying or isolating used devices. However, these are costly and often impractical. We propose other more practical partial defenses as well as a new protocol structure for device-independent quantum key distribution that aims to achieve composable security in the case of two parties using a small number of devices to repeatedly share keys with each other (and no other party).
Device-independent characterizations of a shared quantum state independent of any Bell inequalities
Wei, Zhaohui; Sikora, Jamie
2017-03-01
In a Bell experiment two parties share a quantum state and perform local measurements on their subsystems separately, and the statistics of the measurement outcomes are recorded as a Bell correlation. For any Bell correlation, it turns out that a quantum state with minimal size that is able to produce this correlation can always be pure. In this work, we first exhibit two device-independent characterizations for the pure state that Alice and Bob share using only the correlation data. Specifically, we give two conditions that the Schmidt coefficients must satisfy, which can be tight, and have various applications in quantum tasks. First, one of the characterizations allows us to bound the entanglement between Alice and Bob using Renyi entropies and also to bound the underlying Hilbert space dimension. Second, when the Hilbert space dimension bound is tight, the shared pure quantum state has to be maximally entangled. Third, the second characterization gives a sufficient condition that a Bell correlation cannot be generated by particular quantum states. We also show that our results can be generalized to the case of shared mixed states.
Memory-assisted measurement-device-independent quantum key distribution
International Nuclear Information System (INIS)
Panayi, Christiana; Razavi, Mohsen; Ma, Xiongfeng; Lütkenhaus, Norbert
2014-01-01
A protocol with the potential of beating the existing distance records for conventional quantum key distribution (QKD) systems is proposed. It borrows ideas from quantum repeaters by using memories in the middle of the link, and that of measurement-device-independent QKD, which only requires optical source equipment at the user's end. For certain memories with short access times, our scheme allows a higher repetition rate than that of quantum repeaters with single-mode memories, thereby requiring lower coherence times. By accounting for various sources of nonideality, such as memory decoherence, dark counts, misalignment errors, and background noise, as well as timing issues with memories, we develop a mathematical framework within which we can compare QKD systems with and without memories. In particular, we show that with the state-of-the-art technology for quantum memories, it is potentially possible to devise memory-assisted QKD systems that, at certain distances of practical interest, outperform current QKD implementations. (paper)
Construction of state-independent proofs for quantum contextuality
Tang, Weidong; Yu, Sixia
2017-12-01
Since the enlightening proofs of quantum contextuality first established by Kochen and Specker, and also by Bell, various simplified proofs have been constructed to exclude the noncontextual hidden variable theory of our nature at the microscopic scale. The conflict between the noncontextual hidden variable theory and quantum mechanics is commonly revealed by Kochen-Specker sets of yes-no tests, represented by projectors (or rays), via either logical contradictions or noncontextuality inequalities in a state-(in)dependent manner. Here we propose a systematic and programmable construction of a state-independent proof from a given set of nonspecific rays in C3 according to their Gram matrix. This approach brings us a greater convenience in the experimental arrangements. Besides, our proofs in C3 can also be generalized to any higher-dimensional systems by a recursive method.
Relativeness in quantum gravity: limitations and frame dependence of semiclassical descriptions
International Nuclear Information System (INIS)
Nomura, Yasunori; Sanches, Fabio; Weinberg, Sean J.
2015-01-01
Consistency between quantum mechanical and general relativistic views of the world is a longstanding problem, which becomes particularly prominent in black hole physics. We develop a coherent picture addressing this issue by studying the quantum mechanics of an evolving black hole. After interpreting the Bekenstein-Hawking entropy as the entropy representing the degrees of freedom that are coarse-grained to obtain a semiclassical description from the microscopic theory of quantum gravity, we discuss the properties these degrees of freedom exhibit when viewed from the semiclassical standpoint. We are led to the conclusion that they show features which we call extreme relativeness and spacetime-matter duality — a nontrivial reference frame dependence of their spacetime distribution and the dual roles they play as the “constituents” of spacetime and as thermal radiation. We describe black hole formation and evaporation processes in distant and infalling reference frames, showing that these two properties allow us to avoid the arguments for firewalls and to make the existence of the black hole interior consistent with unitary evolution in the sense of complementarity. Our analysis provides a concrete answer to how information can be preserved at the quantum level throughout the evolution of a black hole, and gives a basic picture of how general coordinate transformations may work at the level of full quantum gravity beyond the approximation of semiclassical theory.
Quantum back-action-evading measurement of motion in a negative mass reference frame
Møller, Christoffer B.; Thomas, Rodrigo A.; Vasilakis, Georgios; Zeuthen, Emil; Tsaturyan, Yeghishe; Balabas, Mikhail; Jensen, Kasper; Schliesser, Albert; Hammerer, Klemens; Polzik, Eugene S.
2017-07-01
Quantum mechanics dictates that a continuous measurement of the position of an object imposes a random quantum back-action (QBA) perturbation on its momentum. This randomness translates with time into position uncertainty, thus leading to the well known uncertainty on the measurement of motion. As a consequence of this randomness, and in accordance with the Heisenberg uncertainty principle, the QBA puts a limitation—the so-called standard quantum limit—on the precision of sensing of position, velocity and acceleration. Here we show that QBA on a macroscopic mechanical oscillator can be evaded if the measurement of motion is conducted in the reference frame of an atomic spin oscillator. The collective quantum measurement on this hybrid system of two distant and disparate oscillators is performed with light. The mechanical oscillator is a vibrational ‘drum’ mode of a millimetre-sized dielectric membrane, and the spin oscillator is an atomic ensemble in a magnetic field. The spin oriented along the field corresponds to an energetically inverted spin population and realizes a negative-effective-mass oscillator, while the opposite orientation corresponds to an oscillator with positive effective mass. The QBA is suppressed by -1.8 decibels in the negative-mass setting and enhanced by 2.4 decibels in the positive-mass case. This hybrid quantum system paves the way to entanglement generation and distant quantum communication between mechanical and spin systems and to sensing of force, motion and gravity beyond the standard quantum limit.
Quantum back-action-evading measurement of motion in a negative mass reference frame.
Møller, Christoffer B; Thomas, Rodrigo A; Vasilakis, Georgios; Zeuthen, Emil; Tsaturyan, Yeghishe; Balabas, Mikhail; Jensen, Kasper; Schliesser, Albert; Hammerer, Klemens; Polzik, Eugene S
2017-07-12
Quantum mechanics dictates that a continuous measurement of the position of an object imposes a random quantum back-action (QBA) perturbation on its momentum. This randomness translates with time into position uncertainty, thus leading to the well known uncertainty on the measurement of motion. As a consequence of this randomness, and in accordance with the Heisenberg uncertainty principle, the QBA puts a limitation-the so-called standard quantum limit-on the precision of sensing of position, velocity and acceleration. Here we show that QBA on a macroscopic mechanical oscillator can be evaded if the measurement of motion is conducted in the reference frame of an atomic spin oscillator. The collective quantum measurement on this hybrid system of two distant and disparate oscillators is performed with light. The mechanical oscillator is a vibrational 'drum' mode of a millimetre-sized dielectric membrane, and the spin oscillator is an atomic ensemble in a magnetic field. The spin oriented along the field corresponds to an energetically inverted spin population and realizes a negative-effective-mass oscillator, while the opposite orientation corresponds to an oscillator with positive effective mass. The QBA is suppressed by -1.8 decibels in the negative-mass setting and enhanced by 2.4 decibels in the positive-mass case. This hybrid quantum system paves the way to entanglement generation and distant quantum communication between mechanical and spin systems and to sensing of force, motion and gravity beyond the standard quantum limit.
Wiestler, Tobias; Waters-Metenier, Sheena; Diedrichsen, Jörn
2014-04-02
Many daily activities rely on the ability to produce meaningful sequences of movements. Motor sequences can be learned in an effector-specific fashion (such that benefits of training are restricted to the trained hand) or an effector-independent manner (meaning that learning also facilitates performance with the untrained hand). Effector-independent knowledge can be represented in extrinsic/world-centered or in intrinsic/body-centered coordinates. Here, we used functional magnetic resonance imaging (fMRI) and multivoxel pattern analysis to determine the distribution of intrinsic and extrinsic finger sequence representations across the human neocortex. Participants practiced four sequences with one hand for 4 d, and then performed these sequences during fMRI with both left and right hand. Between hands, these sequences were equivalent in extrinsic or intrinsic space, or were unrelated. In dorsal premotor cortex (PMd), we found that sequence-specific activity patterns correlated higher for extrinsic than for unrelated pairs, providing evidence for an extrinsic sequence representation. In contrast, primary sensory and motor cortices showed effector-independent representations in intrinsic space, with considerable overlap of the two reference frames in caudal PMd. These results suggest that effector-independent representations exist not only in world-centered, but also in body-centered coordinates, and that PMd may be involved in transforming sequential knowledge between the two. Moreover, although effector-independent sequence representations were found bilaterally, they were stronger in the hemisphere contralateral to the trained hand. This indicates that intermanual transfer relies on motor memories that are laid down during training in both hemispheres, but preferentially draws upon sequential knowledge represented in the trained hemisphere.
PREFACE: Loops 11: Non-Perturbative / Background Independent Quantum Gravity
Mena Marugán, Guillermo A.; Barbero G, J. Fernando; Garay, Luis J.; Villaseñor, Eduardo J. S.; Olmedo, Javier
2012-05-01
Loops 11 The international conference LOOPS'11 took place in Madrid from the 23-28 May 2011. It was hosted by the Instituto de Estructura de la Materia (IEM), which belongs to the Consejo Superior de Investigaciones Cientĺficas (CSIC). Like previous editions of the LOOPS meetings, it dealt with a wealth of state-of-the-art topics on Quantum Gravity, with special emphasis on non-perturbative background-independent approaches to spacetime quantization. The main topics addressed at the conference ranged from the foundations of Quantum Gravity to its phenomenological aspects. They encompassed different approaches to Loop Quantum Gravity and Cosmology, Polymer Quantization, Quantum Field Theory, Black Holes, and discrete approaches such as Dynamical Triangulations, amongst others. In addition, this edition celebrated the 25th anniversary of the introduction of the now well-known Ashtekar variables and the Wednesday morning session was devoted to this silver jubilee. The structure of the conference was designed to reflect the current state and future prospects of research on the different topics mentioned above. Plenary lectures that provided general background and the 'big picture' took place during the mornings, and the more specialised talks were distributed in parallel sessions during the evenings. To be more specific, Monday evening was devoted to Shape Dynamics and Phenomenology Derived from Quantum Gravity in Parallel Session A, and to Covariant Loop Quantum Gravity and Spin foams in Parallel Session B. Tuesday's three Parallel Sessions dealt with Black Hole Physics and Dynamical Triangulations (Session A), the continuation of Monday's session on Covariant Loop Quantum Gravity and Spin foams (Session B) and Foundations of Quantum Gravity (Session C). Finally, Thursday and Friday evenings were devoted to Loop Quantum Cosmology (Session A) and to Hamiltonian Loop Quantum Gravity (Session B). The result of the conference was very satisfactory and enlightening. Not
A novel quasi-master-slave control frame for PV-storage independent microgrid
DEFF Research Database (Denmark)
Yang, Jian; Yuan, Wenbin; Sun, Yao
2018-01-01
In microgrid, photovoltaic (PV) and storage are always combined as a droop-controlled ideal source, which is not very practical. Alternatively, this paper introduces a PV-storage independent system via allocating the PV-storage separately. For this structure, a novel quasi-master-slave control...... frame is proposed without communication. Storages work as master voltage sources, and PVs operate as current controlled voltage sources (CCVS). For the slave PVs, a MPPT-based power droop control and an adaptive reactive power control are proposed. Thus, PVs can simultaneously achieve maximum energy...... is analyzed to design the physical and control parameters, such as, the minimum capacitance value of DC side, droop coefficients. Finally, simulation and experimental results are presented to verify the system effectiveness....
Hydrodynamical expansion with frame independence symmetry in high energy multiparticle production
International Nuclear Information System (INIS)
Chiu, C.B.; Sudarshan, E.C.G.; Wang, K.
1974-01-01
The space--time development of the hadronic system formed immediately after the high energy hadron collision is described with the following picture. Initially the system is highly compressed along the longitudinal direction. The sudden relaxation of this compression leads to a violent acceleration along this direction and perhaps a weak acceleration along the transverse direction. When these accelerations cease, it is proposed that the system acquires a frame independence symmetry with its further expansion governed by the hydrodynamic equation of motion. Within the scheme, this symmetry provides a natural mechanism which eventually leads to a flat inclusive longitudinal rapidity distribution and it also admits a sharp cutoff in the inclusive transverse momentum distribution. The latter is to be contrasted with the prediction of Landau's model, where the average transverse momentum increases with c.m. energy W, [p/sub T/] -W/sup 1 / 6 ./. Finally effects of clustering can also be easily incorporated within the framework. (U.S.)
Hydrodynamical expansion with frame-independence symmetry in high-energy multiparticle production
International Nuclear Information System (INIS)
Chiu, C.B.; Sudarshan, E.; Wang, K.
1975-01-01
We describe the space-time development of the hardronic system formed immediately after the high-energy hadron collision with the following picture. Initially the system is highly compressed along the longitudinal direction. The sudden relaxation of this compression leads to a violent acceration along this direction and perhaps a weak acceleration along the transverse direction. When these accelerations cease, we propose that the system acquires certain frame-independence symmetry with its further expansion governed by the hydrodynamic equation of motion. Within our scheme, this symmetry provides a natural mechanism which eventually leads to a flat inclusive longitudinal rapidity distribution and it also admits a sharp cutoff in the inclusive transverse momentum distribution. These features differ from those of Landau's model
A cost-effective measurement-device-independent quantum key distribution system for quantum networks
Valivarthi, Raju; Zhou, Qiang; John, Caleb; Marsili, Francesco; Verma, Varun B.; Shaw, Matthew D.; Nam, Sae Woo; Oblak, Daniel; Tittel, Wolfgang
2017-12-01
We experimentally realize a measurement-device-independent quantum key distribution (MDI-QKD) system. It is based on cost-effective and commercially available hardware such as distributed feedback lasers and field-programmable gate arrays that enable time-bin qubit preparation and time-tagging, and active feedback systems that allow for compensation of time-varying properties of photons after transmission through deployed fiber. We examine the performance of our system, and conclude that its design does not compromise performance. Our demonstration paves the way for MDI-QKD-based quantum networks in star-type topology that extend over more than 100 km distance.
International Nuclear Information System (INIS)
Lusanna, Luca
2011-01-01
After a review of the problems induced by the Lorentz signature of Minkowski space-time, like the need of a clock synchronization convention for the definition of 3-space and the complexity of the notion of relativistic center of mass, there is the introduction of a new formulation of relativistic quantum mechanics compatible with the theory of relativistic bound states. In it the zeroth postulate of non-relativistic quantum mechanics is not valid and the physics is described in the rest frame by a Hilbert space containing only relative variables. The non-locality of the Poincare' generators imply a kinematical non-locality and non-separability influencing the theory of relativistic entanglement and not connected with the standard quantum non-locality.
Quantum coherence behaviors of fermionic system in non-inertial frame
Huang, Zhiming; Situ, Haozhen
2018-04-01
In this paper, we analyze the quantum coherence behaviors of a single qubit in the relativistic regime beyond the single-mode approximation. Firstly, we investigate the freezing condition of quantum coherence in fermionic system. We also study the quantum coherence tradeoff between particle and antiparticle sector. It is found that there exists quantum coherence transfer between particle and antiparticle sector, but the coherence lost in particle sector is not entirely compensated by the coherence generation of antiparticle sector. Besides, we emphatically discuss the cohering power and decohering power of Unruh channel with respect to the computational basis. It is shown that cohering power is vanishing and decohering power is dependent of the choice of Unruh mode and acceleration. Finally, we compare the behaviors of quantum coherence with geometric quantum discord and entanglement in relativistic setup. Our results show that this quantifiers in two region converge at infinite acceleration limit, which implies that this measures become independent of Unruh modes beyond the single-mode approximations. It is also demonstrated that the robustness of quantum coherence and geometric quantum discord are better than entanglement under the influence of acceleration, since entanglement undergoes sudden death.
Tensorial spacetime geometries and background-independent quantum field theory
International Nuclear Information System (INIS)
Raetzel, Dennis
2012-01-01
Famously, Einstein read off the geometry of spacetime from Maxwell's equations. Today, we take this geometry that serious that our fundamental theory of matter, the standard model of particle physics, is based on it. However, it seems that there is a gap in our understanding if it comes to the physics outside of the solar system. Independent surveys show that we need concepts like dark matter and dark energy to make our models fit with the observations. But these concepts do not fit in the standard model of particle physics. To overcome this problem, at least, we have to be open to matter fields with kinematics and dynamics beyond the standard model. But these matter fields might then very well correspond to different spacetime geometries. This is the basis of this thesis: it studies the underlying spacetime geometries and ventures into the quantization of those matter fields independently of any background geometry. In the first part of this thesis, conditions are identified that a general tensorial geometry must fulfill to serve as a viable spacetime structure. Kinematics of massless and massive point particles on such geometries are introduced and the physical implications are investigated. Additionally, field equations for massive matter fields are constructed like for example a modified Dirac equation. In the second part, a background independent formulation of quantum field theory, the general boundary formulation, is reviewed. The general boundary formulation is then applied to the Unruh effect as a testing ground and first attempts are made to quantize massive matter fields on tensorial spacetimes.
Frame independence of the inhomogeneous mixmaster chaos via Misner-Chitre-like variables
International Nuclear Information System (INIS)
Benini, Riccardo; Montani, Giovanni
2004-01-01
We outline the covariant nature, with respect to the choice of a reference frame, of the chaos characterizing the generic cosmological solution near the initial singularity, i.e., the so-called inhomogeneous mixmaster model. Our analysis is based on a gauge independent Arnowitt-Deser-Misner reduction of the dynamics to the physical degrees of freedom. The resulting picture shows how the inhomogeneous mixmaster model is isomorphic point by point in space to a billiard on a Lobachevsky plane. Indeed, the existence of an asymptotic (energylike) constant of the motion allows one to construct the Jacobi metric associated with the geodesic flow and to calculate a nonzero Lyapunov exponent in each space point. The chaos covariance emerges from the independence of our scheme with respect to the form of the lapse function and the shift vector; the origin of this result relies on the dynamical decoupling of the space points which takes place near the singularity, due to the asymptotic approach of the potential term to infinite walls. At the ground of the obtained dynamical scheme is the choice of Misner-Chitre-like variables which allows one to fix the billiard potential walls
Wang, Lian; Zhou, Yuan-yuan; Zhou, Xue-jun; Chen, Xiao
2018-03-01
Based on the orbital angular momentum and pulse position modulation, we present a novel passive measurement-device-independent quantum key distribution (MDI-QKD) scheme with the two-mode source. Combining with the tight bounds of the yield and error rate of single-photon pairs given in our paper, we conduct performance analysis on the scheme with heralded single-photon source. The numerical simulations show that the performance of our scheme is significantly superior to the traditional MDI-QKD in the error rate, key generation rate and secure transmission distance, since the application of orbital angular momentum and pulse position modulation can exclude the basis-dependent flaw and increase the information content for each single photon. Moreover, the performance is improved with the rise of the frame length. Therefore, our scheme, without intensity modulation, avoids the source side channels and enhances the key generation rate. It has greatly utility value in the MDI-QKD setups.
Detector-device-independent quantum secret sharing with source flaws.
Yang, Xiuqing; Wei, Kejin; Ma, Haiqiang; Liu, Hongwei; Yin, Zhenqiang; Cao, Zhu; Wu, Lingan
2018-04-10
Measurement-device-independent entanglement witness (MDI-EW) plays an important role for detecting entanglement with untrusted measurement device. We present a double blinding-attack on a quantum secret sharing (QSS) protocol based on GHZ state. Using the MDI-EW method, we propose a QSS protocol against all detector side-channels. We allow source flaws in practical QSS system, so that Charlie can securely distribute a key between the two agents Alice and Bob over long distances. Our protocol provides condition on the extracted key rate for the secret against both external eavesdropper and arbitrary dishonest participants. A tight bound for collective attacks can provide good bounds on the practical QSS with source flaws. Then we show through numerical simulations that using single-photon source a secure QSS over 136 km can be achieved.
One-sided measurement-device-independent quantum key distribution
Cao, Wen-Fei; Zhen, Yi-Zheng; Zheng, Yu-Lin; Li, Li; Chen, Zeng-Bing; Liu, Nai-Le; Chen, Kai
2018-01-01
Measurement-device-independent quantum key distribution (MDI-QKD) protocol was proposed to remove all the detector side channel attacks, while its security relies on the trusted encoding systems. Here we propose a one-sided MDI-QKD (1SMDI-QKD) protocol, which enjoys detection loophole-free advantage, and at the same time weakens the state preparation assumption in MDI-QKD. The 1SMDI-QKD can be regarded as a modified MDI-QKD, in which Bob's encoding system is trusted, while Alice's is uncharacterized. For the practical implementation, we also provide a scheme by utilizing coherent light source with an analytical two decoy state estimation method. Simulation with realistic experimental parameters shows that the protocol has a promising performance, and thus can be applied to practical QKD applications.
Case study of a successful learner's epistemological framings of quantum mechanics
Dini, Vesal; Hammer, David
2017-06-01
Research on student epistemologies in introductory courses has highlighted the importance of understanding physics as "a refinement of everyday thinking" [A. Einstein, J. Franklin Inst. 221, 349 (1936), 10.1016/S0016-0032(36)91047-5]. That view is difficult to sustain in quantum mechanics, for students as for physicists. How might students manage the transition? In this article, we present a case study of a graduate student's approaches and reflections on learning over two semesters of quantum mechanics, based on a series of nine interviews. We recount his explicit grappling with the shift in epistemology from classical to quantum, and we argue that his success in learning largely involved his framing mathematics as expressing physical meaning. At the same time, we show he was not entirely stable in these framings, shifting away from them in particular during his study of scattering. The case speaks to literature on students' epistemologies, with respect to the roles of everyday thinking and mathematics. We discuss what this case suggests for further research, with possible implications for instruction.
Rigidity of quantum steering and one-sided device-independent verifiable quantum computation
International Nuclear Information System (INIS)
Gheorghiu, Alexandru; Wallden, Petros; Kashefi, Elham
2017-01-01
The relationship between correlations and entanglement has played a major role in understanding quantum theory since the work of Einstein et al (1935 Phys. Rev. 47 777–80). Tsirelson proved that Bell states, shared among two parties, when measured suitably, achieve the maximum non-local correlations allowed by quantum mechanics (Cirel’son 1980 Lett. Math. Phys. 4 93–100). Conversely, Reichardt et al showed that observing the maximal correlation value over a sequence of repeated measurements, implies that the underlying quantum state is close to a tensor product of maximally entangled states and, moreover, that it is measured according to an ideal strategy (Reichardt et al 2013 Nature 496 456–60). However, this strong rigidity result comes at a high price, requiring a large number of entangled pairs to be tested. In this paper, we present a significant improvement in terms of the overhead by instead considering quantum steering where the device of the one side is trusted. We first demonstrate a robust one-sided device-independent version of self-testing, which characterises the shared state and measurement operators of two parties up to a certain bound. We show that this bound is optimal up to constant factors and we generalise the results for the most general attacks. This leads us to a rigidity theorem for maximal steering correlations. As a key application we give a one-sided device-independent protocol for verifiable delegated quantum computation, and compare it to other existing protocols, to highlight the cost of trust assumptions. Finally, we show that under reasonable assumptions, the states shared in order to run a certain type of verification protocol must be unitarily equivalent to perfect Bell states. (paper)
High-rate measurement-device-independent quantum cryptography
DEFF Research Database (Denmark)
Pirandola, Stefano; Ottaviani, Carlo; Spedalieri, Gaetana
2015-01-01
Quantum cryptography achieves a formidable task - the remote distribution of secret keys by exploiting the fundamental laws of physics. Quantum cryptography is now headed towards solving the practical problem of constructing scalable and secure quantum networks. A significant step in this direction...
Decomposition of Riesz frames and waveletsinto a finite union of linearly independent sets
DEFF Research Database (Denmark)
Christensen, Ole; Lindner, Alexander M
2002-01-01
We characterize Riesz frames and prove that every Riesz frame is the union of a finite number of Riesz sequences. Furthermore, it is shown that for piecewise continuous wavelets with compact support, the associated regular wavelet systems can be decomposed into a finite number of linearly indepen...
On sums of q-independent SUq(2) quantum variables
International Nuclear Information System (INIS)
Lenczewski, R.
1993-01-01
A representation-free approach to the q-analog of the quantum central limit theorem for C=SU 1 (2) is presented. It is shown that for certain functions φε-C* one can derive a version of a quantum central limit theorem (qclt) with √[N] as a scaling parameter, which may be viewed as a q-analog of qclt. (orig.)
Measurement-Device Independency Analysis of Continuous-Variable Quantum Digital Signature
Directory of Open Access Journals (Sweden)
Tao Shang
2018-04-01
Full Text Available With the practical implementation of continuous-variable quantum cryptographic protocols, security problems resulting from measurement-device loopholes are being given increasing attention. At present, research on measurement-device independency analysis is limited in quantum key distribution protocols, while there exist different security problems for different protocols. Considering the importance of quantum digital signature in quantum cryptography, in this paper, we attempt to analyze the measurement-device independency of continuous-variable quantum digital signature, especially continuous-variable quantum homomorphic signature. Firstly, we calculate the upper bound of the error rate of a protocol. If it is negligible on condition that all measurement devices are untrusted, the protocol is deemed to be measurement-device-independent. Then, we simplify the calculation by using the characteristics of continuous variables and prove the measurement-device independency of the protocol according to the calculation result. In addition, the proposed analysis method can be extended to other quantum cryptographic protocols besides continuous-variable quantum homomorphic signature.
International Nuclear Information System (INIS)
Bakke, Knut; Furtado, C.
2010-01-01
We study geometric quantum phases in the relativistic and non-relativistic quantum dynamics of a neutral particle with a permanent magnetic dipole moment interacting with two distinct field configurations in a cosmic string spacetime. We consider the local reference frames of the observers are transported via Fermi-Walker transport and study the influence of the non-inertial effects on the phase shift of the wave function of the neutral particle due to the choice of this local frame. We show that the wave function of the neutral particle acquires non-dispersive relativistic and non-relativistic quantum geometric phases due to the topology of the spacetime, the interaction between the magnetic dipole moment with external fields and the spin-rotation coupling. However, due to the Fermi-Walker reference frame, no phase shift associated to the Sagnac effect appears in the quantum dynamics of a neutral particle. We show that in the absence of topological defect, the contribution to the quantum phase due to the spin-rotation coupling is equivalent to the Mashhoon effect in non-relativistic dynamics. (orig.)
Bell nonlocality: a resource for device-independent quantum information protocols
Acin, Antonio
2015-05-01
Bell nonlocality is not only one of the most fundamental properties of quantum physics, but has also recently acquired the status of an information resource for device-independent quantum information protocols. In the device-independent approach, protocols are designed so that their performance is independent of the internal working of the devices used in the implementation. We discuss all these ideas and argue that device-independent protocols are especially relevant or cryptographic applications, as they are insensitive to hacking attacks exploiting imperfections on the modelling of the devices.
Independence of automorphism group, center, and state space of quantum logics
International Nuclear Information System (INIS)
Navara, M.
1992-01-01
We prove that quantum logics (-orthomodular posets) admit full independence of the attributes important within the foundations of quantum mechanics. Namely, we present the construction of quantum logics with given sublogics (=physical subsystems), automorphism groups, centers (=open-quotes classical partsclose quotes of the systems), and state spaces. Thus, all these open-quotes parametersclose quotes are independent. Our result is rooted in the line of investigation carried out by Greechie; Kallus and Trnkova; Kalmbach; and Navara and Ptak; and considerably enriches the known algebraic methods in orthomodular posets. 19 refs., 1 fig
Device-independent quantum reading and noise-assisted quantum transmitters
International Nuclear Information System (INIS)
Roga, W; Buono, D; Illuminati, F
2015-01-01
In quantum reading, a quantum state of light (transmitter) is applied to read classical information. In the presence of noise or for sufficiently weak signals, quantum reading can outperform classical reading by reason of enhanced state distinguishability. Here we show that enhanced quantum efficiency depends on the presence in the transmitter of a particular type of quantum correlations, the discord of response. Different encodings and transmitters give rise to different levels of efficiency. Considering noisy quantum probes, we show that squeezed thermal transmitters with non-symmetrically distributed noise among the field modes yield higher quantum efficiency compared with coherent thermal quantum states. The noise-enhanced quantum advantage is a consequence of the discord of response being a non-decreasing function of increasing thermal noise under constant squeezing, a behavior that leads to increased state distinguishability. We finally show that, for non-symmetric squeezed thermal states, the probability of error, as measured by the quantum Chernoff bound, vanishes asymptotically with increasing local thermal noise with finite global squeezing. Therefore, with fixed finite squeezing, noisy but strongly discordant quantum states with a large noise imbalance between the field modes can outperform noisy classical resources as well as pure entangled transmitters with the same finite level of squeezing. (paper)
Towards Device-Independent Information Processing on General Quantum Networks
Lee, Ciarán M.; Hoban, Matty J.
2018-01-01
The violation of certain Bell inequalities allows for device-independent information processing secure against nonsignaling eavesdroppers. However, this only holds for the Bell network, in which two or more agents perform local measurements on a single shared source of entanglement. To overcome the practical constraints that entangled systems can only be transmitted over relatively short distances, large-scale multisource networks have been employed. Do there exist analogs of Bell inequalities for such networks, whose violation is a resource for device independence? In this Letter, the violation of recently derived polynomial Bell inequalities will be shown to allow for device independence on multisource networks, secure against nonsignaling eavesdroppers.
Probabilistic deletion of copies of linearly independent quantum states
International Nuclear Information System (INIS)
Feng Jian; Gao Yunfeng; Wang Jisuo; Zhan Mingsheng
2002-01-01
We show that each of two copies of the nonorthogonal states randomly selected from a certain set S can be probabilistically deleted by a general unitary-reduction operation if and only if the states are linearly independent. We derive a tight bound on the best possible deleting efficiencies. These results for 2→1 probabilistic deleting are also generalized into the case of N→M deleting (N,M positive integers and N>M)
Pleskova, S N; Mikheeva, E R
2011-08-01
Inhibition of neutrophilic granulocyte metabolism under the effect of semiconductor quantum points was demonstrated. The status of the oxidative system was evaluated by the NBT test, nonoxidative status by the lysosomal cationic test. It was found that quantum points in a dose of 0.1 mg/ml irrespective of their core and composition of coating significantly inhibited oxygen-dependent and oxygen-independent metabolism of neutrophilic granulocytes.
International Nuclear Information System (INIS)
Tommaso, Anne di; Hagen, Jussara; Tompkins, Van; Muniz, Viviane; Dudakovic, Amel; Kitzis, Alain; Ladeveze, Veronique; Quelle, Dawn E.
2009-01-01
The Alternative Reading Frame (ARF) protein suppresses tumorigenesis through p53-dependent and p53-independent pathways. Most of ARF's anti-proliferative activity is conferred by sequences in its first exon. Previous work showed specific amino acid changes occurred in that region during primate evolution, so we programmed those changes into human p14ARF to assay their functional impact. Two human p14ARF residues (Ala 14 and Thr 31 ) were found to destabilize the protein while two others (Val 24 and Ala 41 ) promoted more efficient p53 stabilization and activation. Despite those effects, all modified p14ARF forms displayed robust p53-dependent anti-proliferative activity demonstrating there are no significant biological differences in p53-mediated growth suppression associated with simian versus human p14ARF residues. In contrast, p53-independent p14ARF function was considerably altered by several residue changes. Val 24 was required for p53-independent growth suppression whereas multiple residues (Val 24 , Thr 31 , Ala 41 and His 60 ) enabled p14ARF to block or reverse the inherent chromosomal instability of p53-null MEFs. Together, these data pinpoint specific residues outside of established p14ARF functional domains that influence its expression and signaling activities. Most intriguingly, this work reveals a novel and direct role for p14ARF in the p53-independent maintenance of genomic stability.
Time–energy high-dimensional one-side device-independent quantum key distribution
International Nuclear Information System (INIS)
Bao Hai-Ze; Bao Wan-Su; Wang Yang; Chen Rui-Ke; Ma Hong-Xin; Zhou Chun; Li Hong-Wei
2017-01-01
Compared with full device-independent quantum key distribution (DI-QKD), one-side device-independent QKD (1sDI-QKD) needs fewer requirements, which is much easier to meet. In this paper, by applying recently developed novel time–energy entropic uncertainty relations, we present a time–energy high-dimensional one-side device-independent quantum key distribution (HD-QKD) and provide the security proof against coherent attacks. Besides, we connect the security with the quantum steering. By numerical simulation, we obtain the secret key rate for Alice’s different detection efficiencies. The results show that our protocol can performance much better than the original 1sDI-QKD. Furthermore, we clarify the relation among the secret key rate, Alice’s detection efficiency, and the dispersion coefficient. Finally, we simply analyze its performance in the optical fiber channel. (paper)
High-Speed Device-Independent Quantum Random Number Generation without a Detection Loophole
Liu, Yang; Yuan, Xiao; Li, Ming-Han; Zhang, Weijun; Zhao, Qi; Zhong, Jiaqiang; Cao, Yuan; Li, Yu-Huai; Chen, Luo-Kan; Li, Hao; Peng, Tianyi; Chen, Yu-Ao; Peng, Cheng-Zhi; Shi, Sheng-Cai; Wang, Zhen; You, Lixing; Ma, Xiongfeng; Fan, Jingyun; Zhang, Qiang; Pan, Jian-Wei
2018-01-01
Quantum mechanics provides the means of generating genuine randomness that is impossible with deterministic classical processes. Remarkably, the unpredictability of randomness can be certified in a manner that is independent of implementation devices. Here, we present an experimental study of device-independent quantum random number generation based on a detection-loophole-free Bell test with entangled photons. In the randomness analysis, without the independent identical distribution assumption, we consider the worst case scenario that the adversary launches the most powerful attacks against the quantum adversary. After considering statistical fluctuations and applying an 80 Gb ×45.6 Mb Toeplitz matrix hashing, we achieve a final random bit rate of 114 bits /s , with a failure probability less than 10-5. This marks a critical step towards realistic applications in cryptography and fundamental physics tests.
Sustained State-Independent Quantum Contextual Correlations from a Single Ion
Leupold, F. M.; Malinowski, M.; Zhang, C.; Negnevitsky, V.; Alonso, J.; Home, J. P.; Cabello, A.
2018-05-01
We use a single trapped-ion qutrit to demonstrate the quantum-state-independent violation of noncontextuality inequalities using a sequence of randomly chosen quantum nondemolition projective measurements. We concatenate 53 ×106 sequential measurements of 13 observables, and unambiguously violate an optimal noncontextual bound. We use the same data set to characterize imperfections including signaling and repeatability of the measurements. The experimental sequence was generated in real time with a quantum random number generator integrated into our control system to select the subsequent observable with a latency below 50 μ s , which can be used to constrain contextual hidden-variable models that might describe our results. The state-recycling experimental procedure is resilient to noise and independent of the qutrit state, substantiating the fact that the contextual nature of quantum physics is connected to measurements and not necessarily to designated states. The use of extended sequences of quantum nondemolition measurements finds applications in the fields of sensing and quantum information.
Experimental test of state-independent quantum contextuality of an indivisible quantum system
Li, Meng; Huang, Yun-Feng; Cao, Dong-Yang; Zhang, Chao; Zhang, Yong-Sheng; Liu, Bi-Heng; Li, Chuan-Feng; Guo, Guang-Can
2014-05-01
Since the quantum mechanics was born, quantum mechanics was argued among scientists because the differences between quantum mechanics and the classical physics. Because of this, some people give hidden variable theory. One of the hidden variable theory is non-contextual hidden variable theory, and KS inequalities are famous in non-contextual hidden variable theory. But the original KS inequalities have 117 directions to measure, so it is almost impossible to test the KS inequalities in experiment. However bout two years ago, Sixia Yu and C.H. Oh point out that for a single qutrit, we only need to measure 13 directions, then we can test the KS inequalities. This makes it possible to test the KS inequalities in experiment. We use the polarization and the path of single photon to construct a qutrit, and we use the half-wave plates, the beam displacers and polar beam splitters to prepare the quantum state and finish the measurement. And the result prove that quantum mechanics is right and non-contextual hidden variable theory is wrong.
Huber, Marcus; Pawlowski, Marcin
2013-01-01
We show that in device independent quantum key distribution protocols the privacy of randomness is of crucial importance. For sublinear test sample sizes even the slightest guessing probability by an eavesdropper will completely compromise security. We show that a combined attack exploiting test sample and measurement choices compromises the security even with a linear size test sample and otherwise device independent security considerations. We explicitly derive the sample size needed to ret...
Experimental study of a quantum random-number generator based on two independent lasers
Sun, Shi-Hai; Xu, Feihu
2017-12-01
A quantum random-number generator (QRNG) can produce true randomness by utilizing the inherent probabilistic nature of quantum mechanics. Recently, the spontaneous-emission quantum phase noise of the laser has been widely deployed for quantum random-number generation, due to its high rate, its low cost, and the feasibility of chip-scale integration. Here, we perform a comprehensive experimental study of a phase-noise-based QRNG with two independent lasers, each of which operates in either continuous-wave (CW) or pulsed mode. We implement the QRNG by operating the two lasers in three configurations, namely, CW + CW, CW + pulsed, and pulsed + pulsed, and demonstrate their trade-offs, strengths, and weaknesses.
Directory of Open Access Journals (Sweden)
Miguel Navascués
2014-01-01
Full Text Available The future progress of semi-device-independent quantum information science depends crucially on our ability to bound the strength of the nonlocal correlations achievable with finite-dimensional quantum resources. In this work, we characterize quantum nonlocality under local dimension constraints via a complete hierarchy of semidefinite programming relaxations. In the bipartite case, we find that the first level of the hierarchy returns nontrivial bounds in all cases considered, allowing us to study nonlocality scenarios with four measurement settings on one side and twelve on the other in a normal desktop. In the tripartite case, we apply the hierarchy to derive a Bell-type inequality that can only be violated when each of the three parties has local dimension greater than 2, hence certifying three-dimensional tripartite entanglement in a device-independent way. Finally, we show how the new method can be trivially modified to detect nonseparable measurements in two-qubit scenarios.
Guo, Ying; Zhao, Wei; Li, Fei; Huang, Duan; Liao, Qin; Xie, Cai-Lang
2017-08-01
The developing tendency of continuous-variable (CV) measurement-device-independent (MDI) quantum cryptography is to cope with the practical issue of implementing scalable quantum networks. Up to now, most theoretical and experimental researches on CV-MDI QKD are focused on two-party protocols. However, we suggest a CV-MDI multipartite quantum secret sharing (QSS) protocol use the EPR states coupled with optical amplifiers. More remarkable, QSS is the real application in multipartite CV-MDI QKD, in other words, is the concrete implementation method of multipartite CV-MDI QKD. It can implement a practical quantum network scheme, under which the legal participants create the secret correlations by using EPR states connecting to an untrusted relay via insecure links and applying the multi-entangled Greenberger-Horne-Zeilinger (GHZ) state analysis at relay station. Even if there is a possibility that the relay may be completely tampered, the legal participants are still able to extract a secret key from network communication. The numerical simulation indicates that the quantum network communication can be achieved in an asymmetric scenario, fulfilling the demands of a practical quantum network. Additionally, we illustrate that the use of optical amplifiers can compensate the partial inherent imperfections of detectors and increase the transmission distance of the CV-MDI quantum system.
Jiang, Cong; Yu, Zong-Wen; Wang, Xiang-Bin
2018-04-01
We present an analysis for measurement-device-independent quantum key distribution with correlated source-light-intensity errors. Numerical results show that the results here can greatly improve the key rate especially with large intensity fluctuations and channel attenuation compared with prior results if the intensity fluctuations of different sources are correlated.
International Nuclear Information System (INIS)
Bakke, Knut
2010-01-01
We study the appearance of bound states analogous to a quantum dot, proposed by Tan and Inkson (1996) , in the non-relativistic quantum dynamics of a neutral particle with permanent magnetic dipole moment induced by the non-inertial effects of the Fermi-Walker reference frame.
Semi-device-independent security of one-way quantum key distribution
Pawlowski, Marcin; Brunner, Nicolas
2011-01-01
By testing nonlocality, the security of entanglement-based quantum key distribution (QKD) can be enhanced to being 'device-independent'. Here we ask whether such a strong form of security could also be established for one-way (prepare and measure) QKD. While fully device-independent security is impossible, we show that security can be guaranteed against individual attacks in a semi-device-independent scenario. In the latter, the devices used by the trusted parties are non-characterized, but t...
Semi-device-independent security of one-way quantum key distribution
International Nuclear Information System (INIS)
Pawlowski, Marcin; Brunner, Nicolas
2011-01-01
By testing nonlocality, the security of entanglement-based quantum key distribution (QKD) can be enhanced to being ''device-independent.'' Here we ask whether such a strong form of security could also be established for one-way (prepare and measure) QKD. While fully device-independent security is impossible, we show that security can be guaranteed against individual attacks in a semi-device-independent scenario. In the latter, the devices used by the trusted parties are noncharacterized, but the dimensionality of the quantum systems used in the protocol is assumed to be bounded. Our security proof relies on the analogies between one-way QKD, dimension witnesses, and random-access codes.
Device-independent secret-key-rate analysis for quantum repeaters
Holz, Timo; Kampermann, Hermann; Bruß, Dagmar
2018-01-01
The device-independent approach to quantum key distribution (QKD) aims to establish a secret key between two or more parties with untrusted devices, potentially under full control of a quantum adversary. The performance of a QKD protocol can be quantified by the secret key rate, which can be lower bounded via the violation of an appropriate Bell inequality in a setup with untrusted devices. We study secret key rates in the device-independent scenario for different quantum repeater setups and compare them to their device-dependent analogon. The quantum repeater setups under consideration are the original protocol by Briegel et al. [Phys. Rev. Lett. 81, 5932 (1998), 10.1103/PhysRevLett.81.5932] and the hybrid quantum repeater protocol by van Loock et al. [Phys. Rev. Lett. 96, 240501 (2006), 10.1103/PhysRevLett.96.240501]. For a given repeater scheme and a given QKD protocol, the secret key rate depends on a variety of parameters, such as the gate quality or the detector efficiency. We systematically analyze the impact of these parameters and suggest optimized strategies.
Li, Fei; Zhao, Wei; Guo, Ying
2018-01-01
Continuous-variable (CV) measurement-device-independent (MDI) quantum cryptography is now heading towards solving the practical problem of implementing scalable quantum networks. In this paper, we show that a solution can come from deploying an optical amplifier in the CV-MDI system, aiming to establish a high-rate quantum network. We suggest an improved CV-MDI protocol using the EPR states coupled with optical amplifiers. It can implement a practical quantum network scheme, where the legal participants create the secret correlations by using EPR states connecting to an untrusted relay via insecure links and applying the multi-entangled Greenberger-Horne-Zeilinger (GHZ) state analysis at relay station. Despite the possibility that the relay could be completely tampered with and imperfect links are subject to the powerful attacks, the legal participants are still able to extract a secret key from network communication. The numerical simulation indicates that the quantum network communication can be achieved in an asymmetric scenario, fulfilling the demands of a practical quantum network. Furthermore, we show that the use of optical amplifiers can compensate the inherent imperfections and improve the secret key rate of the CV-MDI system.
Yin, H-L; Cao, W-F; Fu, Y; Tang, Y-L; Liu, Y; Chen, T-Y; Chen, Z-B
2014-09-15
Measurement-device-independent quantum key distribution (MDI-QKD) with decoy-state method is believed to be securely applied to defeat various hacking attacks in practical quantum key distribution systems. Recently, the coherent-state superpositions (CSS) have emerged as an alternative to single-photon qubits for quantum information processing and metrology. Here, in this Letter, CSS are exploited as the source in MDI-QKD. We present an analytical method that gives two tight formulas to estimate the lower bound of yield and the upper bound of bit error rate. We exploit the standard statistical analysis and Chernoff bound to perform the parameter estimation. Chernoff bound can provide good bounds in the long-distance MDI-QKD. Our results show that with CSS, both the security transmission distance and secure key rate are significantly improved compared with those of the weak coherent states in the finite-data case.
Directory of Open Access Journals (Sweden)
Garrett K. Simon
2018-04-01
Full Text Available Measurement-Device-Independent Quantum Key Distribution (MDI-QKD is a two-photon protocol devised to eliminate eavesdropping attacks that interrogate or control the detector in realized quantum key distribution systems. In MDI-QKD, the measurements are carried out by an untrusted third party, and the measurement results are announced openly. Knowledge or control of the measurement results gives the third party no information about the secret key. Error-free implementation of the MDI-QKD protocol requires the crypto-communicating parties, Alice and Bob, to independently prepare and transmit single photons that are physically indistinguishable, with the possible exception of their polarization states. In this paper, we apply the formalism of quantum optics and Monte Carlo simulations to quantify the impact of small errors in wavelength, bandwidth, polarization and timing between Alice’s photons and Bob’s photons on the MDI-QKD quantum bit error rate (QBER. Using published single-photon source characteristics from two-photon interference experiments as a test case, our simulations predict that the finite tolerances of these sources contribute ( 4.04 ± 20 / N sifted % to the QBER in an MDI-QKD implementation generating an N sifted -bit sifted key.
International Nuclear Information System (INIS)
Wang Yang; Bao Wan-Su; Li Hong-Wei; Zhou Chun; Li Yuan
2014-01-01
Similar to device-independent quantum key distribution (DI-QKD), semi-device-independent quantum key distribution (SDI-QKD) provides secure key distribution without any assumptions about the internal workings of the QKD devices. The only assumption is that the dimension of the Hilbert space is bounded. But SDI-QKD can be implemented in a one-way prepare-and-measure configuration without entanglement compared with DI-QKD. We propose a practical SDI-QKD protocol with four preparation states and three measurement bases by considering the maximal violation of dimension witnesses and specific processes of a QKD protocol. Moreover, we prove the security of the SDI-QKD protocol against collective attacks based on the min-entropy and dimension witnesses. We also show a comparison of the secret key rate between the SDI-QKD protocol and the standard QKD. (general)
Energy Technology Data Exchange (ETDEWEB)
Dosch, H G [Heidelberg Univ. (F.R. Germany). Inst. fuer Theoretische Physik; Mueller, V F [Trier-Kaiserslautern Univ., Kaiserslautern (F.R. Germany). Fachbereich Physik
1975-01-01
Extending the inductive renormalization procedure of Epstein and Glaser which is essentially based on locality, we show that quantum electrodynamics in an external time independent electromagnetic field has a renormalizable formal perturbation expansion. The interaction involving the quantized radiation field but not the action of the external field is treated by perturbation theory. It turns out that vacuum polarization is undetermined in the framework of such a theory.
Arkhipov, S M; Odesskii, A V; Feigin, B; Vassiliev, V
1998-01-01
This volume presents the first collection of articles consisting entirely of work by faculty and students of the Higher Mathematics College of the Independent University of Moscow (IUM). This unique institution was established to train elite students to become research scientists. Covered in the book are two main topics: quantum groups and low-dimensional topology. The articles were written by participants of the Feigin and Vassiliev seminars, two of the most active seminars at the IUM.
Case Study of a Successful Learner's Epistemological Framings of Quantum Mechanics
Dini, Vesal; Hammer, David
2017-01-01
Research on student epistemologies in introductory courses has highlighted the importance of understanding physics as "a refinement of everyday thinking" [A. Einstein, J. Franklin Inst. 221, 349 (1936)]. That view is difficult to sustain in quantum mechanics, for students as for physicists. How might students manage the transition? In…
Reference Frame Fields based on Quantum Theory Representations of Real and Complex Numbers
Benioff, Paul
2007-01-01
A quantum theory representations of real (R) and complex (C) numbers is given that is based on states of single, finite strings of qukits for any base k > 1. Both unary representations and the possibility that qukits with k a prime number are elementary and the rest composite are discussed. Cauchy sequences of qukit string states are defined from the arithmetic properties. The representations of R and C, as equivalence classes of these sequences, differ from classical kit string state represe...
Multi-party Measurement-Device-Independent Quantum Key Distribution Based on Cluster States
Liu, Chuanqi; Zhu, Changhua; Ma, Shuquan; Pei, Changxing
2018-03-01
We propose a novel multi-party measurement-device-independent quantum key distribution (MDI-QKD) protocol based on cluster states. A four-photon analyzer which can distinguish all the 16 cluster states serves as the measurement device for four-party MDI-QKD. Any two out of four participants can build secure keys after the analyzers obtains successful outputs and the two participants perform post-processing. We derive a security analysis for the protocol, and analyze the key rates under different values of polarization misalignment. The results show that four-party MDI-QKD is feasible over 280 km in the optical fiber channel when the key rate is about 10- 6 with the polarization misalignment parameter 0.015. Moreover, our work takes an important step toward a quantum communication network.
International Nuclear Information System (INIS)
Wang Le; Zhao Sheng-Mei; Cheng Wei-Wen; Gong Long-Yan
2015-01-01
In this paper, we propose a measurement-device-independent quantum-key-distribution (MDI-QKD) protocol using orbital angular momentum (OAM) in free space links, named the OAM-MDI-QKD protocol. In the proposed protocol, the OAM states of photons, instead of polarization states, are used as the information carriers to avoid the reference frame alignment, the decoy-state is adopted to overcome the security loophole caused by the weak coherent pulse source, and the high efficient OAM-sorter is adopted as the measurement tool for Charlie to obtain the output OAM state. Here, Charlie may be an untrusted third party. The results show that the authorized users, Alice and Bob, could distill a secret key with Charlie’s successful measurements, and the key generation performance is slightly better than that of the polarization-based MDI-QKD protocol in the two-dimensional OAM cases. Simultaneously, Alice and Bob can reduce the number of flipping the bits in the secure key distillation. It is indicated that a higher key generation rate performance could be obtained by a high dimensional OAM-MDI-QKD protocol because of the unlimited degree of freedom on OAM states. Moreover, the results show that the key generation rate and the transmission distance will decrease as the growth of the strength of atmospheric turbulence (AT) and the link attenuation. In addition, the decoy states used in the proposed protocol can get a considerable good performance without the need for an ideal source. (paper)
International Nuclear Information System (INIS)
Kwon, Osung; Lee, Min-Soo; Woo, Min Ki; Park, Byung Kwon; Kim, Il Young; Kim, Yong-Su; Han, Sang-Wook; Moon, Sung
2015-01-01
We characterized a polarization-independent phase modulation method, called double phase modulation, for a practical plug and play quantum key distribution (QKD) system. Following investigation of theoretical backgrounds, we applied the method to the practical QKD system and characterized the performance through comparing single phase modulation (SPM) and double phase modulation. Consequently, we obtained repeatable and accurate phase modulation confirmed by high visibility single photon interference even for input signals with arbitrary polarization. Further, the results show that only 80% of the bias voltage required in the case of single phase modulation is needed to obtain the target amount of phase modulation. (paper)
On pure spinor formalism for quantum superstring and spinor moving frame
International Nuclear Information System (INIS)
Bandos, Igor A
2013-01-01
The D = 10 pure spinor constraint can be solved in terms of spinor moving frame variables v -α q and eight-component complex null vector Λ + q , Λ + q Λ + q =0, which can be related to the κ-symmetry ghost. Using this and similar solutions for the conjugate pure spinor and other elements of the non-minimal pure spinor formalism, we present a (hopefully useful) reformulation of the measure of the pure spinor path integral for superstring in terms of products of Cartan forms corresponding to the coset of 10D Lorentz group and to the coset of complex orthogonal group SO(8, C). Our study suggests a possible complete reformulation of the pure spinor superstring in terms of new irreducible set of variable. (paper)
Remote unambiguous discrimination of linearly independent symmetric d-level quantum states
International Nuclear Information System (INIS)
Chen Libing; Liu Yuhua; Tan Peng; Lu Hong
2009-01-01
A set of linearly independent nonorthogonal symmetric d-level quantum states can be discriminated remotely and unambiguously with the aid of two-level Einstein-Podolsky-Rosen (EPR) states. We present a scheme for such a kind of remote unambiguous quantum state discrimination (UD). The probability of discrimination is in agreement with the optimal probability for local unambiguous discrimination among d symmetric states (Chefles and Barnettt 1998 Phys. Lett. A 250 223). This scheme consists of a remote generalized measurement described by a positive operator valued measurement (POVM). This remote POVM can be realized by performing a nonlocal 2d x 2d unitary operation on two spatially separated systems, one is the qudit which is encoded by one of the d symmetric nonorthogonal states to be distinguished and the other is an ancillary qubit, and a conventional local von Neumann orthogonal measurement on the ancilla. By decomposing the evolution process from the initial state to the final state, we construct a quantum network for realizing the remote POVM with a set of two-level nonlocal controlled-rotation gates, and thus provide a feasible physical means to realize the remote UD. A two-level nonlocal controlled-rotation gate can be implemented by using a two-level EPR pair in addition to local operations and classical communications (LOCCs)
Riccati and Ermakov Equations in Time-Dependent and Time-Independent Quantum Systems
Directory of Open Access Journals (Sweden)
Dieter Schuch
2008-05-01
Full Text Available The time-evolution of the maximum and the width of exact analytic wave packet (WP solutions of the time-dependent Schrödinger equation (SE represents the particle and wave aspects, respectively, of the quantum system. The dynamics of the maximum, located at the mean value of position, is governed by the Newtonian equation of the corresponding classical problem. The width, which is directly proportional to the position uncertainty, obeys a complex nonlinear Riccati equation which can be transformed into a real nonlinear Ermakov equation. The coupled pair of these equations yields a dynamical invariant which plays a key role in our investigation. It can be expressed in terms of a complex variable that linearizes the Riccati equation. This variable also provides the time-dependent parameters that characterize the Green's function, or Feynman kernel, of the corresponding problem. From there, also the relation between the classical and quantum dynamics of the systems can be obtained. Furthermore, the close connection between the Ermakov invariant and the Wigner function will be shown. Factorization of the dynamical invariant allows for comparison with creation/annihilation operators and supersymmetry where the partner potentials fulfil (real Riccati equations. This provides the link to a nonlinear formulation of time-independent quantum mechanics in terms of an Ermakov equation for the amplitude of the stationary state wave functions combined with a conservation law. Comparison with SUSY and the time-dependent problems concludes our analysis.
A monogamy-of-entanglement game with applications to device-independent quantum cryptography
International Nuclear Information System (INIS)
Tomamichel, Marco; Kaniewski, Jędrzej; Wehner, Stephanie; Fehr, Serge
2013-01-01
We consider a game in which two separate laboratories collaborate to prepare a quantum system and are then asked to guess the outcome of a measurement performed by a third party in a random basis on that system. Intuitively, by the uncertainty principle and the monogamy of entanglement, the probability that both players simultaneously succeed in guessing the outcome correctly is bounded. We are interested in the question of how the success probability scales when many such games are performed in parallel. We show that any strategy that maximizes the probability to win every game individually is also optimal for the parallel repetition of the game. Our result implies that the optimal guessing probability can be achieved without the use of entanglement. We explore several applications of this result. Firstly, we show that it implies security for standard BB84 quantum key distribution when the receiving party uses fully untrusted measurement devices, i.e. we show that BB84 is one-sided device independent. Secondly, we show how our result can be used to prove security of a one-round position-verification scheme. Finally, we generalize a well-known uncertainty relation for the guessing probability to quantum side information. (paper)
International Nuclear Information System (INIS)
McKague, Matthew
2009-01-01
Device independent quantum key distribution (QKD) aims to provide a higher degree of security than traditional QKD schemes by reducing the number of assumptions that need to be made about the physical devices used. The previous proof of security by Pironio et al (2009 New J. Phys. 11 045021) applies only to collective attacks where the state is identical and independent and the measurement devices operate identically for each trial in the protocol. We extend this result to a more general class of attacks where the state is arbitrary and the measurement devices have no memory. We accomplish this by a reduction of arbitrary adversary strategies to qubit strategies and a proof of security for qubit strategies based on the previous proof by Pironio et al and techniques adapted from Renner.
Zhao, Yijia; Zhang, Yichen; Xu, Bingjie; Yu, Song; Guo, Hong
2018-04-01
The method of improving the performance of continuous-variable quantum key distribution protocols by postselection has been recently proposed and verified. In continuous-variable measurement-device-independent quantum key distribution (CV-MDI QKD) protocols, the measurement results are obtained from untrusted third party Charlie. There is still not an effective method of improving CV-MDI QKD by the postselection with untrusted measurement. We propose a method to improve the performance of coherent-state CV-MDI QKD protocol by virtual photon subtraction via non-Gaussian postselection. The non-Gaussian postselection of transmitted data is equivalent to an ideal photon subtraction on the two-mode squeezed vacuum state, which is favorable to enhance the performance of CV-MDI QKD. In CV-MDI QKD protocol with non-Gaussian postselection, two users select their own data independently. We demonstrate that the optimal performance of the renovated CV-MDI QKD protocol is obtained with the transmitted data only selected by Alice. By setting appropriate parameters of the virtual photon subtraction, the secret key rate and tolerable excess noise are both improved at long transmission distance. The method provides an effective optimization scheme for the application of CV-MDI QKD protocols.
Note: A pure-sampling quantum Monte Carlo algorithm with independent Metropolis
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Vrbik, Jan [Department of Mathematics, Brock University, St. Catharines, Ontario L2S 3A1 (Canada); Ospadov, Egor; Rothstein, Stuart M., E-mail: srothstein@brocku.ca [Department of Physics, Brock University, St. Catharines, Ontario L2S 3A1 (Canada)
2016-07-14
Recently, Ospadov and Rothstein published a pure-sampling quantum Monte Carlo algorithm (PSQMC) that features an auxiliary Path Z that connects the midpoints of the current and proposed Paths X and Y, respectively. When sufficiently long, Path Z provides statistical independence of Paths X and Y. Under those conditions, the Metropolis decision used in PSQMC is done without any approximation, i.e., not requiring microscopic reversibility and without having to introduce any G(x → x′; τ) factors into its decision function. This is a unique feature that contrasts with all competing reptation algorithms in the literature. An example illustrates that dependence of Paths X and Y has adverse consequences for pure sampling.
Note: A pure-sampling quantum Monte Carlo algorithm with independent Metropolis
International Nuclear Information System (INIS)
Vrbik, Jan; Ospadov, Egor; Rothstein, Stuart M.
2016-01-01
Recently, Ospadov and Rothstein published a pure-sampling quantum Monte Carlo algorithm (PSQMC) that features an auxiliary Path Z that connects the midpoints of the current and proposed Paths X and Y, respectively. When sufficiently long, Path Z provides statistical independence of Paths X and Y. Under those conditions, the Metropolis decision used in PSQMC is done without any approximation, i.e., not requiring microscopic reversibility and without having to introduce any G(x → x′; τ) factors into its decision function. This is a unique feature that contrasts with all competing reptation algorithms in the literature. An example illustrates that dependence of Paths X and Y has adverse consequences for pure sampling.
Continuous-variable measurement-device-independent quantum key distribution with photon subtraction
Ma, Hong-Xin; Huang, Peng; Bai, Dong-Yun; Wang, Shi-Yu; Bao, Wan-Su; Zeng, Gui-Hua
2018-04-01
It has been found that non-Gaussian operations can be applied to increase and distill entanglement between Gaussian entangled states. We show the successful use of the non-Gaussian operation, in particular, photon subtraction operation, on the continuous-variable measurement-device-independent quantum key distribution (CV-MDI-QKD) protocol. The proposed method can be implemented based on existing technologies. Security analysis shows that the photon subtraction operation can remarkably increase the maximal transmission distance of the CV-MDI-QKD protocol, which precisely make up for the shortcoming of the original CV-MDI-QKD protocol, and one-photon subtraction operation has the best performance. Moreover, the proposed protocol provides a feasible method for the experimental implementation of the CV-MDI-QKD protocol.
Self-referenced continuous-variable measurement-device-independent quantum key distribution
Wang, Yijun; Wang, Xudong; Li, Jiawei; Huang, Duan; Zhang, Ling; Guo, Ying
2018-05-01
We propose a scheme to remove the demand of transmitting a high-brightness local oscillator (LO) in continuous-variable measurement-device-independent quantum key distribution (CV-MDI QKD) protocol, which we call as the self-referenced (SR) CV-MDI QKD. We show that our scheme is immune to the side-channel attacks, such as the calibration attacks, the wavelength attacks and the LO fluctuation attacks, which are all exploiting the security loopholes introduced by transmitting the LO. Besides, the proposed scheme waives the necessity of complex multiplexer and demultiplexer, which can greatly simplify the QKD processes and improve the transmission efficiency. The numerical simulations under collective attacks show that all the improvements brought about by our scheme are only at the expense of slight transmission distance shortening. This scheme shows an available method to mend the security loopholes incurred by transmitting LO in CV-MDI QKD.
Finite-size analysis of continuous-variable measurement-device-independent quantum key distribution
Zhang, Xueying; Zhang, Yichen; Zhao, Yijia; Wang, Xiangyu; Yu, Song; Guo, Hong
2017-10-01
We study the impact of the finite-size effect on the continuous-variable measurement-device-independent quantum key distribution (CV-MDI QKD) protocol, mainly considering the finite-size effect on the parameter estimation procedure. The central-limit theorem and maximum likelihood estimation theorem are used to estimate the parameters. We also analyze the relationship between the number of exchanged signals and the optimal modulation variance in the protocol. It is proved that when Charlie's position is close to Bob, the CV-MDI QKD protocol has the farthest transmission distance in the finite-size scenario. Finally, we discuss the impact of finite-size effects related to the practical detection in the CV-MDI QKD protocol. The overall results indicate that the finite-size effect has a great influence on the secret-key rate of the CV-MDI QKD protocol and should not be ignored.
International Nuclear Information System (INIS)
Guta, Madalin; Bowles, Peter; Adesso, Gerardo
2010-01-01
A successful state-transfer (or teleportation) experiment must perform better than the benchmark set by the 'best' measure and prepare procedure. We consider the benchmark problem for the following families of states: (i) displaced thermal equilibrium states of a given temperature; (ii) independent identically prepared qubits with a completely unknown state. For the first family we show that the optimal procedure is heterodyne measurement followed by the preparation of a coherent state. This procedure was known to be optimal for coherent states and for squeezed states with the 'overlap fidelity' as the figure of merit. Here, we prove its optimality with respect to the trace norm distance and supremum risk. For the second problem we consider n independent and identically distributed (i.i.d.) spin-(1/2) systems in an arbitrary unknown state ρ and look for the measurement-preparation pair (M n ,P n ) for which the reconstructed state ω n :=P n circle M n (ρ xn ) is as close as possible to the input state (i.e., parallel ω n -ρ xn parallel 1 is small). The figure of merit is based on the trace norm distance between the input and output states. We show that asymptotically with n this problem is equivalent to the first one. The proof and construction of (M n ,P n ) uses the theory of local asymptotic normality developed for state estimation which shows that i.i.d. quantum models can be approximated in a strong sense by quantum Gaussian models. The measurement part is identical to 'optimal estimation', showing that 'benchmarking' and estimation are closely related problems in the asymptotic set up.
Detector-device-independent quantum key distribution: Security analysis and fast implementation
International Nuclear Information System (INIS)
Boaron, Alberto; Korzh, Boris; Boso, Gianluca; Martin, Anthony; Zbinden, Hugo; Houlmann, Raphael; Lim, Charles Ci Wen
2016-01-01
One of the most pressing issues in quantum key distribution (QKD) is the problem of detector side-channel attacks. To overcome this problem, researchers proposed an elegant “time-reversal” QKD protocol called measurement-device-independent QKD (MDI-QKD), which is based on time-reversed entanglement swapping. However, MDI-QKD is more challenging to implement than standard point-to-point QKD. Recently, an intermediary QKD protocol called detector-device-independent QKD (DDI-QKD) has been proposed to overcome the drawbacks of MDI-QKD, with the hope that it would eventually lead to a more efficient detector side-channel-free QKD system. Here, we analyze the security of DDI-QKD and elucidate its security assumptions. We find that DDI-QKD is not equivalent to MDI-QKD, but its security can be demonstrated with reasonable assumptions. On the more practical side, we consider the feasibility of DDI-QKD and present a fast experimental demonstration (clocked at 625 MHz), capable of secret key exchange up to more than 90 km.
Gehring, Tobias; Händchen, Vitus; Duhme, Jörg; Furrer, Fabian; Franz, Torsten; Pacher, Christoph; Werner, Reinhard F; Schnabel, Roman
2015-10-30
Secret communication over public channels is one of the central pillars of a modern information society. Using quantum key distribution this is achieved without relying on the hardness of mathematical problems, which might be compromised by improved algorithms or by future quantum computers. State-of-the-art quantum key distribution requires composable security against coherent attacks for a finite number of distributed quantum states as well as robustness against implementation side channels. Here we present an implementation of continuous-variable quantum key distribution satisfying these requirements. Our implementation is based on the distribution of continuous-variable Einstein-Podolsky-Rosen entangled light. It is one-sided device independent, which means the security of the generated key is independent of any memoryfree attacks on the remote detector. Since continuous-variable encoding is compatible with conventional optical communication technology, our work is a step towards practical implementations of quantum key distribution with state-of-the-art security based solely on telecom components.
Gehring, Tobias; Händchen, Vitus; Duhme, Jörg; Furrer, Fabian; Franz, Torsten; Pacher, Christoph; Werner, Reinhard F.; Schnabel, Roman
2015-10-01
Secret communication over public channels is one of the central pillars of a modern information society. Using quantum key distribution this is achieved without relying on the hardness of mathematical problems, which might be compromised by improved algorithms or by future quantum computers. State-of-the-art quantum key distribution requires composable security against coherent attacks for a finite number of distributed quantum states as well as robustness against implementation side channels. Here we present an implementation of continuous-variable quantum key distribution satisfying these requirements. Our implementation is based on the distribution of continuous-variable Einstein-Podolsky-Rosen entangled light. It is one-sided device independent, which means the security of the generated key is independent of any memoryfree attacks on the remote detector. Since continuous-variable encoding is compatible with conventional optical communication technology, our work is a step towards practical implementations of quantum key distribution with state-of-the-art security based solely on telecom components.
Weber, Jonas H.; Kettler, Jan; Vural, Hüseyin; Müller, Markus; Maisch, Julian; Jetter, Michael; Portalupi, Simone L.; Michler, Peter
2018-05-01
As a fundamental building block for quantum computation and communication protocols, the correct verification of the two-photon interference (TPI) contrast between two independent quantum light sources is of utmost importance. Here, we experimentally demonstrate how frequently present blinking dynamics and changes in emitter brightness critically affect the Hong-Ou-Mandel-type (HOM) correlation histograms of remote TPI experiments measured via the commonly utilized setup configuration. We further exploit this qualitative and quantitative explanation of the observed correlation dynamics to establish an alternative interferometer configuration, which is overcoming the discussed temporal fluctuations, giving rise to an error-free determination of the remote TPI visibility. We prove full knowledge of the obtained correlation by reproducing the measured correlation statistics via Monte Carlo simulations. As an exemplary system, we make use of two pairs of remote semiconductor quantum dots; however, the same conclusions apply for TPI experiments with flying qubits from any kind of remote solid-state quantum emitters.
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Zhu, Feng; Zhang, Chun-Hui; Liu, Ai-Ping [Institute of Signal Processing Transmission, Nanjing University of Posts and Telecommunications, Nanjing 210003 (China); Key Lab of Broadband Wireless Communication and Sensor Network Technology, Nanjing University of Posts and Telecommunications, Ministry of Education, Nanjing 210003 (China); Wang, Qin, E-mail: qinw@njupt.edu.cn [Institute of Signal Processing Transmission, Nanjing University of Posts and Telecommunications, Nanjing 210003 (China); Key Lab of Broadband Wireless Communication and Sensor Network Technology, Nanjing University of Posts and Telecommunications, Ministry of Education, Nanjing 210003 (China); Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026 (China)
2016-04-01
In this paper, we propose to implement the heralded pair-coherent source into the measurement-device-independent quantum key distribution. By comparing its performance with other existing schemes, we demonstrate that our new scheme can overcome many shortcomings existing in current schemes, and show excellent behavior in the quantum key distribution. Moreover, even when taking the statistical fluctuation into account, we can still obtain quite high key generation rate at very long transmission distance by using our new scheme. - Highlights: • Implement the heralded pair-coherent source into the measurement-device-independent quantum key distribution. • Overcome many shortcomings existing in current schemes and show excellent behavior. • Obtain quite high key generation rate even when taking statistical fluctuation into account.
International Nuclear Information System (INIS)
Chand, F.
2010-01-01
Exact fourth-order constants of motion are investigated for three-dimensional classical and quantum Hamiltonian systems. The rationalization method is utilized to obtain constants of motion for classical systems. Constants of motion for quantum systems are obtained by adding quantum correction terms, computed using Moyal's bracket, to the corresponding classical counterparts. (author)
Energy Technology Data Exchange (ETDEWEB)
Wu, Feng; Ren, Yinghui; Bian, Wensheng, E-mail: bian@iccas.ac.cn [Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); University of Chinese Academy of Sciences, Beijing 100049 (China)
2016-08-21
The accurate time-independent quantum dynamics calculations on the ground-state tunneling splitting of malonaldehyde in full dimensionality are reported for the first time. This is achieved with an efficient method developed by us. In our method, the basis functions are customized for the hydrogen transfer process which has the effect of greatly reducing the size of the final Hamiltonian matrix, and the Lanczos method and parallel strategy are used to further overcome the memory and central processing unit time bottlenecks. The obtained ground-state tunneling splitting of 24.5 cm{sup −1} is in excellent agreement with the benchmark value of 23.8 cm{sup −1} computed with the full-dimensional, multi-configurational time-dependent Hartree approach on the same potential energy surface, and we estimate that our reported value has an uncertainty of less than 0.5 cm{sup −1}. Moreover, the role of various vibrational modes strongly coupled to the hydrogen transfer process is revealed.
Wang, Le; Zhao, Sheng-Mei; Gong, Long-Yan; Cheng, Wei-Wen
2015-12-01
In this paper, we propose a measurement-device-independent quantum-key-distribution (MDI-QKD) protocol using orbital angular momentum (OAM) in free space links, named the OAM-MDI-QKD protocol. In the proposed protocol, the OAM states of photons, instead of polarization states, are used as the information carriers to avoid the reference frame alignment, the decoy-state is adopted to overcome the security loophole caused by the weak coherent pulse source, and the high efficient OAM-sorter is adopted as the measurement tool for Charlie to obtain the output OAM state. Here, Charlie may be an untrusted third party. The results show that the authorized users, Alice and Bob, could distill a secret key with Charlie’s successful measurements, and the key generation performance is slightly better than that of the polarization-based MDI-QKD protocol in the two-dimensional OAM cases. Simultaneously, Alice and Bob can reduce the number of flipping the bits in the secure key distillation. It is indicated that a higher key generation rate performance could be obtained by a high dimensional OAM-MDI-QKD protocol because of the unlimited degree of freedom on OAM states. Moreover, the results show that the key generation rate and the transmission distance will decrease as the growth of the strength of atmospheric turbulence (AT) and the link attenuation. In addition, the decoy states used in the proposed protocol can get a considerable good performance without the need for an ideal source. Project supported by the National Natural Science Foundation of China (Grant Nos. 61271238 and 61475075), the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20123223110003), the Natural Science Research Foundation for Universities of Jiangsu Province of China (Grant No. 11KJA510002), the Open Research Fund of Key Laboratory of Broadband Wireless Communication and Sensor Network Technology, Ministry of Education, China (Grant No. NYKL2015011), and the
Todd McElroy; John J. Seta
2007-01-01
We examined how the goal of a decision task influences the perceived positive, negative valence of the alternatives and thereby the likelihood and direction of framing effects. In Study 1 we manipulated the goal to increase, decrease or maintain the commodity in question and found that when the goal of the task was to increase the commodity, a framing effect consistent with those typically observed in the literature was found. When the goal was to decrease, a framing effect opposite to the ty...
International Nuclear Information System (INIS)
An, Nguyen Ba; Bich, Cao Thi
2014-01-01
We construct a quantum circuit to produce a task-oriented partially entangled state and use it as the quantum channel for controlled joint remote state preparation. Unlike most previous works, where the parameters of the quantum channel are given to the receiver who can accomplish the task only probabilistically by consuming auxiliary resource, operation and measurement, here we give them to the supervisor. Thanks to the knowledge of the task-oriented quantum channel parameters, the supervisor can carry out proper complete projective measurement, which, combined with the feed-forward technique adapted by the preparers, not only much economizes (simplifies) the receiver's resource (operation) but also yields unit total success probability. Notably, such apparent perfection does not depend on the entanglement degree of the shared quantum channel. Our protocol is within the reach of current quantum technologies. - Highlights: • Controlled joint remote state preparation is considered. • Quantum circuit is proposed to produce task-oriented partially entangled channel. • The quantum channel parameter is given to the supervisor (not to the receiver). • Unit success probability without additional resource/operations/measurement. • Perfection is achieved regardless of the shared entanglement degree
On sums of q-independent SU[sub q](2) quantum variables
Energy Technology Data Exchange (ETDEWEB)
Lenczewski, R. (Politechnika Wroclawska, Wroclaw (Poland). Hugo Steinhaus Center for Stochastic Methods)
1993-05-01
A representation-free approach to the q-analog of the quantum central limit theorem for C=SU[sub 1](2) is presented. It is shown that for certain functions [phi][epsilon]-C* one can derive a version of a quantum central limit theorem (qclt) with [radical][N] as a scaling parameter, which may be viewed as a q-analog of qclt. (orig.).
Ge, Shuaipeng; Zhang, Lisheng; Wang, Peijie; Fang, Yan
2016-01-01
Nanoscale phosphorene quantum dots (PQDs) with few-layer structures were fabricated by pulsed laser ablation of a bulk black phosphorus target in diethyl ether. An intense and stable photoluminescence (PL) emission of the PQDs in the blue-violet wavelength region is clearly observed for the first time, which is attributed to electronic transitions from the lowest unoccupied molecular orbital (LUMO) to the highest occupied molecular orbital (HOMO) and occupied molecular orbitals below the HOMO (H-1, H-2), respectively. Surprisingly, the PL emission peak positions of the PQDs are not red-shifted with progressively longer excitation wavelengths, which is in contrast to the cases of graphene and molybdenum disulphide quantum dots. This excitation wavelength-independence is derived from the saturated passivation on the periphery and surfaces of the PQDs by large numbers of electron-donating functional groups which cause the electron density on the PQDs to be dramatically increased and the band gap to be insensitive to the quantum size effect in the PQDs. This work suggests that PQDs with intense, stable and excitation wavelength-independent PL emission in the blue-violet region have a potential application as semiconductor-based blue-violet light irradiation sources. PMID:27265198
Directory of Open Access Journals (Sweden)
Todd McElroy
2007-08-01
Full Text Available We examined how the goal of a decision task influences the perceived positive, negative valence of the alternatives and thereby the likelihood and direction of framing effects. In Study 1 we manipulated the goal to increase, decrease or maintain the commodity in question and found that when the goal of the task was to increase the commodity, a framing effect consistent with those typically observed in the literature was found. When the goal was to decrease, a framing effect opposite to the typical findings was observed whereas when the goal was to maintain, no framing effect was found. When we examined the decisions of the entire population, we did not observe a framing effect. In Study 2, we provided participants with a similar decision task except in this situation the goal was ambiguous, allowing us to observe participants' self-imposed goals and how they influenced choice preferences. The findings from Study 2 demonstrated individual variability in imposed goal and provided a conceptual replication of Study 1. %need keywords
Independent attacks in imperfect settings: A case for a two-way quantum key distribution scheme
International Nuclear Information System (INIS)
Shaari, J.S.; Bahari, Iskandar
2010-01-01
We review the study on a two-way quantum key distribution protocol given imperfect settings through a simple analysis of a toy model and show that it can outperform a BB84 setup. We provide the sufficient condition for this as a ratio of optimal intensities for the protocols.
A monogamy-of-entanglement game with applications to device-independent quantum cryptography
M. Tomamichel; S. Fehr (Serge); J. Kaniewski; S.D.C. Wehner (Stephanie); T. Johansson; P.Q. Nguyen
2013-01-01
htmlabstractWe consider a game in which two separate laboratories collaborate to prepare a quantum system and are then asked to guess the outcome of a measurement performed by a third party in a random basis on that system. Intuitively, by the uncertainty principle and the monogamy of entanglement,
International Nuclear Information System (INIS)
Bouchard, A.M.
1994-01-01
This report discusses the following topics: Bloch oscillations and other dynamical phenomena of electrons in semiconductor superlattices; solvable dynamical model of an electron in a one-dimensional aperiodic lattice subject to a uniform electric field; and quantum dynamical phenomena of electrons in aperiodic semiconductor superlattices
Compliance Framing - Framing Compliance
Lutz-Ulrich Haack; Martin C. Reimann
2012-01-01
Corporations have to install various organizational measures to comply with legal as well as internal guidelines systematically. Compliance management systems have the challenging task to make use of an internal compliance-marketing approach in order to ensure not only an adequate but also effective compliance-culture. Compliance-literature and findings of persuasive goal-framing-theory give opposite implications for establishing a rather values- versus rule-based compliance-culture respectiv...
National Research Council Canada - National Science Library
Matson, Charles; Haji, Alim
2007-01-01
Multi-frame blind deconvolution (MFBD) algorithms can be used to generate a deblurred image of an object from a sequence of short-exposure and atmospherically-blurred images of the object by jointly estimating the common object...
Li, Na; Zhang, Yu; Wen, Shuang; Li, Lei-lei; Li, Jian
2018-01-01
Noise is a problem that communication channels cannot avoid. It is, thus, beneficial to analyze the security of MDI-QKD in noisy environment. An analysis model for collective-rotation noise is introduced, and the information theory methods are used to analyze the security of the protocol. The maximum amount of information that Eve can eavesdrop is 50%, and the eavesdropping can always be detected if the noise level ɛ ≤ 0.68. Therefore, MDI-QKD protocol is secure as quantum key distribution protocol. The maximum probability that the relay outputs successful results is 16% when existing eavesdropping. Moreover, the probability that the relay outputs successful results when existing eavesdropping is higher than the situation without eavesdropping. The paper validates that MDI-QKD protocol has better robustness.
Optimal primitive reference frames
International Nuclear Information System (INIS)
Jennings, David
2011-01-01
We consider the smallest possible directional reference frames allowed and determine the best one can ever do in preserving quantum information in various scenarios. We find that for the preservation of a single spin state, two orthogonal spins are optimal primitive reference frames; and in a product state, they do approximately 22% as well as an infinite-sized classical frame. By adding a small amount of entanglement to the reference frame, this can be raised to 2(2/3) 5 =26%. Under the different criterion of entanglement preservation, a very similar optimal reference frame is found; however, this time it is for spins aligned at an optimal angle of 87 deg. In this case 24% of the negativity is preserved. The classical limit is considered numerically, and indicates under the criterion of entanglement preservation, that 90 deg. is selected out nonmonotonically, with a peak optimal angle of 96.5 deg. for L=3 spins.
Zhou, Xing-Yu; Zhang, Chun-Hui; Zhang, Chun-Mei; Wang, Qin
2017-11-01
Measurement-device-independent quantum key distribution (MDI-QKD) has been widely investigated due to its remarkable advantages on the achievable transmission distance and practical security. However, the relative low key generation rate limits its real-life implementations. In this work, we adopt the newly proposed four-intensity decoy-state scheme [Phys. Rev. A 93, 042324 (2016), 10.1103/PhysRevA.93.042324] to study the performance of MDI-QKD with heralded single-photon sources (HSPS). Corresponding simulation results demonstrate that the four-intensity decoy-state scheme combining HSPS can drastically improve both the key generation rate and transmission distance in MDI-QKD, which may be very promising in future MDI-QKD systems.
International Nuclear Information System (INIS)
Wang Yang; Bao Wan-Su; Chen Rui-Ke; Zhou Chun; Jiang Mu-Sheng; Li Hong-Wei
2017-01-01
Measurement-device-independent quantum key distribution (MDI-QKD) is immune to detector side channel attacks, which is a crucial security loophole problem in traditional QKD. In order to relax a key assumption that the sources are trusted in MDI-QKD, an MDI-QKD protocol with an untrusted source has been proposed. For the security of MDI-QKD with an untrusted source, imperfections in the practical experiment should also be taken into account. In this paper, we analyze the effects of fluctuations of internal transmittance on the security of a decoy-state MDI-QKD protocol with an untrusted source. Our numerical results show that both the secret key rate and the maximum secure transmission distance decrease when taken fluctuations of internal transmittance into consideration. Especially, they are more sensitive when Charlie’s mean photon number per pulse is smaller. Our results emphasize that the stability of correlative optical devices is important for practical implementations . (paper)
Akibue, Seiseki; Kato, Go
2018-04-01
For distinguishing quantum states sampled from a fixed ensemble, the gap in bipartite and single-party distinguishability can be interpreted as a nonlocality of the ensemble. In this paper, we consider bipartite state discrimination in a composite system consisting of N subsystems, where each subsystem is shared between two parties and the state of each subsystem is randomly sampled from a particular ensemble comprising the Bell states. We show that the success probability of perfectly identifying the state converges to 1 as N →∞ if the entropy of the probability distribution associated with the ensemble is less than 1, even if the success probability is less than 1 for any finite N . In other words, the nonlocality of the N -fold ensemble asymptotically disappears if the probability distribution associated with each ensemble is concentrated. Furthermore, we show that the disappearance of the nonlocality can be regarded as a remarkable counterexample of a fundamental open question in theoretical computer science, called a parallel repetition conjecture of interactive games with two classically communicating players. Measurements for the discrimination task include a projective measurement of one party represented by stabilizer states, which enable the other party to perfectly distinguish states that are sampled with high probability.
Discretization independence implies non-locality in 4D discrete quantum gravity
Dittrich, Bianca; Kamiński, Wojciech; Steinhaus, Sebastian
2014-12-01
The 4D Regge action is invariant under 5-1 and 4-2 Pachner moves, which define a subset of (local) changes of the triangulation. Given this fact, one might hope to find a local path integral measure that makes the quantum theory invariant under these moves and hence makes the theory partially triangulation invariant. We show that such a local invariant path integral measure does not exist for the 4D linearized Regge theory. To this end we uncover an interesting geometric interpretation for the Hessian of the 4D Regge action. This geometric interpretation will allow us to prove that the determinant of the Hessian of the 4D Regge action does not factorize over four-simplices or subsimplices. It furthermore allows us to determine configurations where this Hessian vanishes, which only appears to be the case in degenerate backgrounds or if one allows for different orientations of the simplices. We suggest a non-local measure factor that absorbs the non-local part of the determinant of the Hessian under 5-1 moves as well as a local measure factor that is preserved for very special configurations.
Discretization independence implies non-locality in 4D discrete quantum gravity
International Nuclear Information System (INIS)
Dittrich, Bianca; Kamiński, Wojciech; Steinhaus, Sebastian
2014-01-01
The 4D Regge action is invariant under 5–1 and 4–2 Pachner moves, which define a subset of (local) changes of the triangulation. Given this fact, one might hope to find a local path integral measure that makes the quantum theory invariant under these moves and hence makes the theory partially triangulation invariant. We show that such a local invariant path integral measure does not exist for the 4D linearized Regge theory. To this end we uncover an interesting geometric interpretation for the Hessian of the 4D Regge action. This geometric interpretation will allow us to prove that the determinant of the Hessian of the 4D Regge action does not factorize over four-simplices or subsimplices. It furthermore allows us to determine configurations where this Hessian vanishes, which only appears to be the case in degenerate backgrounds or if one allows for different orientations of the simplices. We suggest a non-local measure factor that absorbs the non-local part of the determinant of the Hessian under 5–1 moves as well as a local measure factor that is preserved for very special configurations. (paper)
International Nuclear Information System (INIS)
Antoine, Jean-Pierre; Balazs, Peter
2011-01-01
Loosely speaking, a semi-frame is a generalized frame for which one of the frame bounds is absent. More precisely, given a total sequence in a Hilbert space, we speak of an upper (resp. lower) semi-frame if only the upper (resp. lower) frame bound is valid. Equivalently, for an upper semi-frame, the frame operator is bounded, but has an unbounded inverse, whereas a lower semi-frame has an unbounded frame operator, with a bounded inverse. We study mostly upper semi-frames, both in the continuous and discrete case, and give some remarks for the dual situation. In particular, we show that reconstruction is still possible in certain cases.
Assaraf, Roland
2014-12-01
We show that the recently proposed correlated sampling without reweighting procedure extends the locality (asymptotic independence of the system size) of a physical property to the statistical fluctuations of its estimator. This makes the approach potentially vastly more efficient for computing space-localized properties in large systems compared with standard correlated methods. A proof is given for a large collection of noninteracting fragments. Calculations on hydrogen chains suggest that this behavior holds not only for systems displaying short-range correlations, but also for systems with long-range correlations.
International Nuclear Information System (INIS)
Zeiger, E.M.
1978-01-01
New equations are presented for three- and four-body scattering, within the context of nonrelativistic quantum mechanics and a Hamiltonian scattering theory. For the three-body case Faddeev-type equations are presented which, although obtained from the rigorous Faddeev theory, only require two-body bound state wave functions and half-off-shell transition amplitudes as input. In addition, their effective potentials are independent of the three-body energy, and can easily be made real after an angular momentum decomposition. The equations are formulated in terms of physical transition amplitudes for three-body processes, except that in the breakup case the partial-wave amplitudes differ from the corresponding full amplitudes by a Watson final-state-interaction factor. Also presented are new equations for four-body scattering, obtained by generalizing our three-body formalism to the four-body case. These equations, although equivalent to those of Faddeev--Yakubovskii, are expressed in terms of singularity-free transition amplitudes, and their energy-independent effective potentials require only half-on-shell subsystem transition amplitudes (and bound state wave functions) as input. However, due to the detailed index structure of the Faddeev--Yakubovskii formalsim, the result of the generalization is considerably more complicated than in the three-body case
Semenov, Alexander; Babikov, Dmitri
2013-11-07
We formulated the mixed quantum/classical theory for rotationally and vibrationally inelastic scattering process in the diatomic molecule + atom system. Two versions of theory are presented, first in the space-fixed and second in the body-fixed reference frame. First version is easy to derive and the resultant equations of motion are transparent, but the state-to-state transition matrix is complex-valued and dense. Such calculations may be computationally demanding for heavier molecules and/or higher temperatures, when the number of accessible channels becomes large. In contrast, the second version of theory requires some tedious derivations and the final equations of motion are rather complicated (not particularly intuitive). However, the state-to-state transitions are driven by real-valued sparse matrixes of much smaller size. Thus, this formulation is the method of choice from the computational point of view, while the space-fixed formulation can serve as a test of the body-fixed equations of motion, and the code. Rigorous numerical tests were carried out for a model system to ensure that all equations, matrixes, and computer codes in both formulations are correct.
International Nuclear Information System (INIS)
Semenov, Alexander; Babikov, Dmitri
2013-01-01
We formulated the mixed quantum/classical theory for rotationally and vibrationally inelastic scattering process in the diatomic molecule + atom system. Two versions of theory are presented, first in the space-fixed and second in the body-fixed reference frame. First version is easy to derive and the resultant equations of motion are transparent, but the state-to-state transition matrix is complex-valued and dense. Such calculations may be computationally demanding for heavier molecules and/or higher temperatures, when the number of accessible channels becomes large. In contrast, the second version of theory requires some tedious derivations and the final equations of motion are rather complicated (not particularly intuitive). However, the state-to-state transitions are driven by real-valued sparse matrixes of much smaller size. Thus, this formulation is the method of choice from the computational point of view, while the space-fixed formulation can serve as a test of the body-fixed equations of motion, and the code. Rigorous numerical tests were carried out for a model system to ensure that all equations, matrixes, and computer codes in both formulations are correct
DEFF Research Database (Denmark)
Pedersen, Rasmus T.
2017-01-01
The concept of media framing refers to the way in which the news media organize and provide meaning to a news story by emphasizing some parts of reality and disregarding other parts. These patterns of emphasis and exclusion in news coverage create frames that can have considerable effects on news...... consumers’ perceptions and attitudes regarding the given issue or event. This entry briefly elaborates on the concept of media framing, presents key types of media frames, and introduces the research on media framing effects....
Ciufolini, Ignazio
2007-09-06
The origin of inertia has intrigued scientists and philosophers for centuries. Inertial frames of reference permeate our daily life. The inertial and centrifugal forces, such as the pull and push that we feel when our vehicle accelerates, brakes and turns, arise because of changes in velocity relative to uniformly moving inertial frames. A classical interpretation ascribed these forces to acceleration relative to some absolute frame independent of the cosmological matter, whereas an opposite view related them to acceleration relative to all the masses and 'fixed stars' in the Universe. An echo and partial realization of the latter idea can be found in Einstein's general theory of relativity, which predicts that a spinning mass will 'drag' inertial frames along with it. Here I review the recent measurements of frame dragging using satellites orbiting Earth.
Shiri, Fereshteh; Pirhadi, Somayeh; Ghasemi, Jahan B
2016-03-01
Mer receptor tyrosine kinase is a promising novel cancer therapeutic target in many human cancers, because abnormal activation of Mer has been implicated in survival signaling and chemoresistance. 3D-QSAR analyses based on alignment independent descriptors were performed on a series of 81 Mer specific tyrosine kinase inhibitors. The fractional factorial design (FFD) and the enhanced replacement method (ERM) were applied and tested as variable selection algorithms for the selection of optimal subsets of molecular descriptors from a much greater pool of such regression variables. The data set was split into 65 molecules as the training set and 16 compounds as the test set. All descriptors were generated by using the GRid INdependent descriptors (GRIND) approach. After variable selection, GRIND were correlated with activity values (pIC50) by PLS regression. Of the two applied variable selection methods, ERM had a noticeable improvement on the statistical parameters of PLS model, and yielded a q (2) value of 0.77, an [Formula: see text] of 0.94, and a low RMSEP value of 0.25. The GRIND information contents influencing the affinity on Mer specific tyrosine kinase were also confirmed by docking studies. In a quantum calculation study, the energy difference between HOMO and LUMO (gap) implied the high interaction of the most active molecule in the active site of the protein. In addition, the molecular electrostatic potential energy at DFT level confirmed results obtained from the molecular docking. The identified key features obtained from the molecular modeling, enabled us to design novel kinase inhibitors.
Directory of Open Access Journals (Sweden)
Fereshteh Shiri
2016-03-01
Full Text Available Mer receptor tyrosine kinase is a promising novel cancer therapeutic target in many human cancers, because abnormal activation of Mer has been implicated in survival signaling and chemoresistance. 3D-QSAR analyses based on alignment independent descriptors were performed on a series of 81 Mer specific tyrosine kinase inhibitors. The fractional factorial design (FFD and the enhanced replacement method (ERM were applied and tested as variable selection algorithms for the selection of optimal subsets of molecular descriptors from a much greater pool of such regression variables. The data set was split into 65 molecules as the training set and 16 compounds as the test set. All descriptors were generated by using the GRid INdependent descriptors (GRIND approach. After variable selection, GRIND were correlated with activity values (pIC50 by PLS regression. Of the two applied variable selection methods, ERM had a noticeable improvement on the statistical parameters of PLS model, and yielded a q2 value of 0.77, an rpred2 of 0.94, and a low RMSEP value of 0.25. The GRIND information contents influencing the affinity on Mer specific tyrosine kinase were also confirmed by docking studies. In a quantum calculation study, the energy difference between HOMO and LUMO (gap implied the high interaction of the most active molecule in the active site of the protein. In addition, the molecular electrostatic potential energy at DFT level confirmed results obtained from the molecular docking. The identified key features obtained from the molecular modeling, enabled us to design novel kinase inhibitors.
Effective Hamiltonians in quantum physics: resonances and geometric phase
International Nuclear Information System (INIS)
Rau, A R P; Uskov, D
2006-01-01
Effective Hamiltonians are often used in quantum physics, both in time-dependent and time-independent contexts. Analogies are drawn between the two usages, the discussion framed particularly for the geometric phase of a time-dependent Hamiltonian and for resonances as stationary states of a time-independent Hamiltonian
Al-Khalili, Jim
2003-01-01
In this lively look at quantum science, a physicist takes you on an entertaining and enlightening journey through the basics of subatomic physics. Along the way, he examines the paradox of quantum mechanics--beautifully mathematical in theory but confoundingly unpredictable in the real world. Marvel at the Dual Slit experiment as a tiny atom passes through two separate openings at the same time. Ponder the peculiar communication of quantum particles, which can remain in touch no matter how far apart. Join the genius jewel thief as he carries out a quantum measurement on a diamond without ever touching the object in question. Baffle yourself with the bizzareness of quantum tunneling, the equivalent of traveling partway up a hill, only to disappear then reappear traveling down the opposite side. With its clean, colorful layout and conversational tone, this text will hook you into the conundrum that is quantum mechanics.
DEFF Research Database (Denmark)
Gehring, Tobias; Haendchen, Vitus; Duhme, Joerg
2015-01-01
Secret communication over public channels is one of the central pillars of a modern information society. Using quantum key distribution this is achieved without relying on the hardness of mathematical problems, which might be compromised by improved algorithms or by future quantum computers. State......-of-the-art quantum key distribution requires composable security against coherent attacks for a finite number of distributed quantum states as well as robustness against implementation side channels. Here we present an implementation of continuous-variable quantum key distribution satisfying these requirements. Our...... with conventional optical communication technology, our work is a step towards practical implementations of quantum key distribution with state-of-the-art security based solely on telecom components....
de Vreese, C.H.; Lecheler, S.; Mazzoleni, G.; Barnhurst, K.G.; Ikeda, K.; Maia, R.C.M.; Wessler, H.
2016-01-01
Political issues can be viewed from different perspectives and they can be defined differently in the news media by emphasizing some aspects and leaving others aside. This is at the core of news framing theory. Framing originates within sociology and psychology and has become one of the most used
DEFF Research Database (Denmark)
Peder Pedersen, Claus
2018-01-01
On framing as artistic and conceptual tool in the works of Claudia Carbone. Contribution to exhibition at the Aarhus School of Architecture.......On framing as artistic and conceptual tool in the works of Claudia Carbone. Contribution to exhibition at the Aarhus School of Architecture....
Lecheler, S.K.
2010-01-01
This dissertation supplies a number of research findings that add to a theory of news framing effects, and also to the understanding of the role media effects play in political communication. We show that researchers must think more about what actually constitutes a framing effect, and that a
Ran Spiegler
2014-01-01
I present a simple framework for modeling two-firm market competition when consumer choice is "frame-dependent", and firms use costless "marketing messages" to influence the consumer's frame. This framework embeds several recent models in the "behavioral industrial organization" literature. I identify a property that consumer choice may satisfy, which extends the concept of Weighted Regularity due to Piccione and Spiegler (2012), and provide a characterization of Nash equilibria under this pr...
Reeder, Blaine; Meyer, Ellen; Lazar, Amanda; Chaudhuri, Shomir; Thompson, Hilaire J; Demiris, George
2013-07-01
There is a critical need for public health interventions to support the independence of older adults as the world's population ages. Health smart homes (HSH) and home-based consumer health (HCH) technologies may play a role in these interventions. We conducted a systematic review of HSH and HCH literature from indexed repositories for health care and technology disciplines (e.g., MEDLINE, CINAHL, and IEEE Xplore) and classified included studies according to an evidence-based public health (EBPH) typology. One thousand, six hundred and thirty-nine candidate articles were identified. Thirty-one studies from the years 1998-2011 were included. Twenty-one included studies were classified as emerging, 10 as promising and 3 as effective (first tier). The majority of included studies were published in the period beginning in the year 2005. All 3 effective (first tier) studies and 9 of 10 of promising studies were published during this period. Almost all studies included an activity sensing component and most of them used passive infrared motion sensors. The three effective (first tier) studies all used a multicomponent technology approach that included activity sensing, reminders and other technologies tailored to individual preferences. Future research should explore the use of technology for self-management of health by older adults; social support; and self-reported health measures incorporated into personal health records, electronic medical records, and community health registries. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.
Han, Deguang; Larson, David; Weber, Eric
2007-01-01
Frames for Undergraduates is an undergraduate-level introduction to the theory of frames in a Hilbert space. This book can serve as a text for a special-topics course in frame theory, but it could also be used to teach a second semester of linear algebra, using frames as an application of the theoretical concepts. It can also provide a complete and helpful resource for students doing undergraduate research projects using frames. The early chapters contain the topics from linear algebra that students need to know in order to read the rest of the book. The later chapters are devoted to advanced topics, which allow students with more experience to study more intricate types of frames. Toward that end, a Student Presentation section gives detailed proofs of fairly technical results with the intention that a student could work out these proofs independently and prepare a presentation to a class or research group. The authors have also presented some stories in the Anecdotes section about how this material has moti...
Semenov, Alexander; Dubernet, Marie-Lise; Babikov, Dmitri
2014-09-21
The mixed quantum/classical theory (MQCT) for inelastic molecule-atom scattering developed recently [A. Semenov and D. Babikov, J. Chem. Phys. 139, 174108 (2013)] is extended to treat a general case of an asymmetric-top-rotor molecule in the body-fixed reference frame. This complements a similar theory formulated in the space-fixed reference-frame [M. Ivanov, M.-L. Dubernet, and D. Babikov, J. Chem. Phys. 140, 134301 (2014)]. Here, the goal was to develop an approximate computationally affordable treatment of the rotationally inelastic scattering and apply it to H2O + He. We found that MQCT is somewhat less accurate at lower scattering energies. For example, below E = 1000 cm(-1) the typical errors in the values of inelastic scattering cross sections are on the order of 10%. However, at higher scattering energies MQCT method appears to be rather accurate. Thus, at scattering energies above 2000 cm(-1) the errors are consistently in the range of 1%-2%, which is basically our convergence criterion with respect to the number of trajectories. At these conditions our MQCT method remains computationally affordable. We found that computational cost of the fully-coupled MQCT calculations scales as n(2), where n is the number of channels. This is more favorable than the full-quantum inelastic scattering calculations that scale as n(3). Our conclusion is that for complex systems (heavy collision partners with many internal states) and at higher scattering energies MQCT may offer significant computational advantages.
Framing scales and scaling frames
van Lieshout, M.; Dewulf, A.; Aarts, N.; Termeer, K.
2009-01-01
Policy problems are not just out there. Actors highlight different aspects of a situation as problematic and situate the problem on different scales. In this study we will analyse the way actors apply scales in their talk (or texts) to frame the complex decision-making process of the establishment
DEFF Research Database (Denmark)
Haase, Louise Møller; Laursen, Linda Nhu
2017-01-01
Designing a remarkable product innovation is a difficult challenge, which businesses today continuously are striving to tackle. This challenge is particularly present in the early phase of innovation, where the main product concept and frames of the innovation is determined. As a main challenge...... in the early phase is the reasoning process; innovation team are faced with open-ended ill-defines problems, where they need to make decisions about an unknown future having only incomplete, ambiguous and contradicting insights available. We study the reasoning of experts, how they frame to make sense of all...... the insights and create a basis for decision making in relation to a new project. Based on case studies of five innovative products from various industries, we suggest a Product Reasoning Model for understanding reasoning and envisioning of new product innovations in the early phases...
DEFF Research Database (Denmark)
Haase, Louise Møller; Laursen, Linda Nhu
2017-01-01
Designing a remarkable product innovation is a difficult challenge, which businesses today continuously are striving to tackle. This challenge is particularly present in the early phase of innovation, where the main product concept and frames of the innovation is determined. As a main challenge...... in the early phase is the reasoning process; innovation team are faced with open- ended ill-defines problems, where they need to make decisions about an unknown future having only incomplete, ambiguous and contradicting insights available. We study the reasoning of experts, how they frame to make sense of all...... the insights and create a basis for decision making in relation to a new project. Based on case studies of five innovative products from various industries, we suggest a Product Reasoning Model for understanding reasoning and envisioning of new product innovations in the early phases of innovation....
Quantum foundations in the light of quantum cryptography
International Nuclear Information System (INIS)
Brassard, G.; Fuchs, C.A.
2005-01-01
Full text: Consider the two great physical theories of the twentieth century: relativity and quantum mechanics. Einstein derived relativity from very simple principles such as: 'The speed of light in empty space is independent of the speed of its source' and 'Physics should appear the same in all inertial reference frames'. By contrast, the foundation of quantum mechanics is built on a set of rather strange, disjointed and ad hoc axioms. Why is that? Must quantum mechanics be inherently less elegant than relativity? Or is it rather that the current axioms of quantum mechanics reflect at best the history that led to its discovery by too many people (compared to one person for relativity), over too long a period of time? The purpose of this talk is to argue that a better foundation for quantum mechanics lies within the teachings of quantum information science. We postulate that the truly fundamental laws of nature concern information, not waves or particles. For example, it has been proven, from the current axioms of quantum mechanics, that 'nature allows for the unconditionally secure transmission of confidential information', but 'nature does not allow for unconditionally secure bit commitment' (these are standard classical cryptographic primitives). We propose to turn the table around, start from these two theorems and possibly a few others, upgrade them as axioms, and ask how much of quantum mechanics they can derive. This provocative talk is meant as an eye-opener: we shall ask far more questions than we shall resolve. (author)
Amaku, Marcos; Coutinho, Francisco A. B.; Masafumi Toyama, F.
2017-09-01
The usual definition of the time evolution operator e-i H t /ℏ=∑n=0∞1/n ! (-i/ℏHt ) n , where H is the Hamiltonian of the system, as given in almost every book on quantum mechanics, causes problems in some situations. The operators that appear in quantum mechanics are either bounded or unbounded. Unbounded operators are not defined for all the vectors (wave functions) of the Hilbert space of the system; when applied to some states, they give a non-normalizable state. Therefore, if H is an unbounded operator, the definition in terms of the power series expansion does not make sense because it may diverge or result in a non-normalizable wave function. In this article, we explain why this is so and suggest, as an alternative, another definition used by mathematicians.
Basak, Jyotirmoy; Maitra, Subhamoy
2018-04-01
In device-independent (DI) paradigm, the trustful assumptions over the devices are removed and CHSH test is performed to check the functionality of the devices toward certifying the security of the protocol. The existing DI protocols consider infinite number of samples from theoretical point of view, though this is not practically implementable. For finite sample analysis of the existing DI protocols, we may also consider strategies for checking device independence other than the CHSH test. In this direction, here we present a comparative analysis between CHSH and three-party Pseudo-telepathy game for the quantum private query protocol in DI paradigm that appeared in Maitra et al. (Phys Rev A 95:042344, 2017) very recently.
Gauge Invariance and Frame Independence in Cosmology
Weenink, J.G.
2013-01-01
In this thesis the mathematical formulation of cosmological perturbations is studied. First we discuss the gauge problem of general relativity: perturbations of the metric and matter fields in an expanding universe are dependent on the choice of coordinate system, i.e. gauge dependent, even though
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.
Non-minimal Higgs inflation and frame dependence in cosmology
International Nuclear Information System (INIS)
Steinwachs, Christian F.; Kamenshchik, Alexander Yu.
2013-01-01
We investigate a very general class of cosmological models with scalar fields non-minimally coupled to gravity. A particular representative in this class is given by the non-minimal Higgs inflation model in which the Standard Model Higgs boson and the inflaton are described by one and the same scalar particle. While the predictions of the non-minimal Higgs inflation scenario come numerically remarkably close to the recently discovered mass of the Higgs boson, there remains a conceptual problem in this model that is associated with the choice of the cosmological frame. While the classical theory is independent of this choice, we find by an explicit calculation that already the first quantum corrections induce a frame dependence. We give a geometrical explanation of this frame dependence by embedding it into a more general field theoretical context. From this analysis, some conceptional points in the long lasting cosmological debate: 'Jordan frame vs. Einstein frame' become more transparent and in principle can be resolved in a natural way.
Non-minimal Higgs inflation and frame dependence in cosmology
Energy Technology Data Exchange (ETDEWEB)
Steinwachs, Christian F. [School of Mathematical Sciences, University of Nottingham University Park, Nottingham, NG7 2RD (United Kingdom); Kamenshchik, Alexander Yu. [Dipartimento di Fisica e Astronomia and INFN, Via Irnerio 46, 40126 Bologna, Italy and L.D. Landau Institute for Theoretical Physics of the Russian Academy of Sciences, Kosygin str. 2, 119334 Moscow (Russian Federation)
2013-02-21
We investigate a very general class of cosmological models with scalar fields non-minimally coupled to gravity. A particular representative in this class is given by the non-minimal Higgs inflation model in which the Standard Model Higgs boson and the inflaton are described by one and the same scalar particle. While the predictions of the non-minimal Higgs inflation scenario come numerically remarkably close to the recently discovered mass of the Higgs boson, there remains a conceptual problem in this model that is associated with the choice of the cosmological frame. While the classical theory is independent of this choice, we find by an explicit calculation that already the first quantum corrections induce a frame dependence. We give a geometrical explanation of this frame dependence by embedding it into a more general field theoretical context. From this analysis, some conceptional points in the long lasting cosmological debate: 'Jordan frame vs. Einstein frame' become more transparent and in principle can be resolved in a natural way.
Chen, Horng-Shyang; Liu, Zhan Hui; Shih, Pei-Ying; Su, Chia-Ying; Chen, Chih-Yen; Lin, Chun-Han; Yao, Yu-Feng; Kiang, Yean-Woei; Yang, C C
2014-04-07
A reverse-biased voltage is applied to either device in the vertical configuration of two light-emitting diodes (LEDs) grown on patterned and flat Si (110) substrates with weak and strong quantum-confined Stark effects (QCSEs), respectively, in the InGaN/GaN quantum wells for independently controlling the applied voltage across and the injection current into the p-i-n junction in the lateral configuration of LED operation. The results show that more carrier supply is needed in the LED of weaker QCSE to produce a carrier screening effect for balancing the potential tilt in increasing the forward-biased voltage, when compared with the LED of stronger QCSE. The small spectral shift range in increasing injection current in the LED of weaker QCSE is attributed not only to the weaker QCSE, but also to its smaller device resistance such that a given increment of applied voltage leads to a larger increment of injection current. From a viewpoint of practical application in LED operation, by applying a reverse-biased voltage in the vertical configuration, the applied voltage and injection current in the lateral configuration can be independently controlled by adjusting the vertical voltage for keeping the emission spectral peak fixed.
An introduction to finite tight frames
Waldron, Shayne F D
2018-01-01
This textbook is an introduction to the theory and applications of finite tight frames, an area that has developed rapidly in the last decade. Stimulating much of this growth are the applications of finite frames to diverse fields such as signal processing, quantum information theory, multivariate orthogonal polynomials, and remote sensing. Key features and topics: * First book entirely devoted to finite frames * Extensive exercises and MATLAB examples for classroom use * Important examples, such as harmonic and Heisenberg frames, are presented in preliminary chapters, encouraging readers to explore and develop an intuitive feeling for tight frames * Later chapters delve into general theory details and recent research results * Many illustrations showing the special aspects of the geometry of finite frames * Provides an overview of the field of finite tight frames * Discusses future research directions in the field Featuring exercises and MATLAB examples in each chapter, the book is well suited as a textbook ...
Scaling solutions for dilaton quantum gravity
Energy Technology Data Exchange (ETDEWEB)
Henz, T.; Pawlowski, J.M., E-mail: j.pawlowski@thphys.uni-heidelberg.de; Wetterich, C.
2017-06-10
Scaling solutions for the effective action in dilaton quantum gravity are investigated within the functional renormalization group approach. We find numerical solutions that connect ultraviolet and infrared fixed points as the ratio between scalar field and renormalization scale k is varied. In the Einstein frame the quantum effective action corresponding to the scaling solutions becomes independent of k. The field equations derived from this effective action can be used directly for cosmology. Scale symmetry is spontaneously broken by a non-vanishing cosmological value of the scalar field. For the cosmology corresponding to our scaling solutions, inflation arises naturally. The effective cosmological constant becomes dynamical and vanishes asymptotically as time goes to infinity.
Orthogonality and quantum geometry: Towards a relational reconstruction of quantum theory
Zhong, S.
2015-01-01
This thesis is an in-depth mathematical study of the non-orthogonality relation between the (pure) states of quantum systems. In Chapter 2, I define quantum Kripke frames, the protagonists of this thesis. A quantum Kripke frame is a Kripke frame in which the binary relation possesses some simple
Symmetries of collective models in intrinsic frame
International Nuclear Information System (INIS)
Gozdz, A.; Pedrak, A.; Szulerecka, A.; Dobrowolski, A.; Dudek, J.
2013-01-01
In the paper a very general definition of intrinsic frame, by means of group theoretical methods, is introduced. It allows to analyze nuclear properties which are invariant in respect to the group which defines the intrinsic frame. For example, nuclear shape is a well determined feature in the intrinsic frame defined by the Euclidean group. It is shown that using of intrinsic frame gives an opportunity to consider intrinsic nuclear symmetries which are independent of symmetries observed in the laboratory frame. An importance of the notion of partial symmetries is emphasized. (author)
On frame multiresolution analysis
DEFF Research Database (Denmark)
Christensen, Ole
2003-01-01
We use the freedom in frame multiresolution analysis to construct tight wavelet frames (even in the case where the refinable function does not generate a tight frame). In cases where a frame multiresolution does not lead to a construction of a wavelet frame we show how one can nevertheless...
Werfelli, Ghofran; Halvick, Philippe; Honvault, Pascal; Kerkeni, Boutheïna; Stoecklin, Thierry
2015-09-21
The observed abundances of the methylidyne cation, CH(+), in diffuse molecular clouds can be two orders of magnitude higher than the prediction of the standard gas-phase models which, in turn, predict rather well the abundances of neutral CH. It is therefore necessary to investigate all the possible formation and destruction processes of CH(+) in the interstellar medium with the most abundant species H, H2, and e(-). In this work, we address the destruction process of CH(+) by hydrogen abstraction. We report a new calculation of the low temperature rate coefficients for the abstraction reaction, using accurate time-independent quantum scattering and a new high-level ab initio global potential energy surface including a realistic model of the long-range interaction between the reactants H and CH(+). The calculated thermal rate coefficient is in good agreement with the experimental data in the range 50 K-800 K. However, at lower temperatures, the experimental rate coefficient takes exceedingly small values which are not reproduced by the calculated rate coefficient. Instead, the latter rate coefficient is close to the one given by the Langevin capture model, as expected for a reaction involving an ion and a neutral species. Several recent theoretical works have reported a seemingly good agreement with the experiment below 50 K, but an analysis of these works show that they are based on potential energy surfaces with incorrect long-range behavior. The experimental results were explained by a loss of reactivity of the lowest rotational states of the reactant; however, the quantum scattering calculations show the opposite, namely, a reactivity enhancement with rotational excitation.
Nonmonotonic belief state frames and reasoning frames
Engelfriet, J.; Herre, H.; Treur, J.
1995-01-01
In this paper five levels of specification of nonmonotonic reasoning are distinguished. The notions of semantical frame, belief state frame and reasoning frame are introduced and used as a semantical basis for the first three levels. Moreover, the semantical connections between the levels are
Bayse, Craig A; Merz, Kenneth M
2014-08-05
Understanding the mechanism of prenyltransferases is important to the design of engineered proteins capable of synthesizing derivatives of naturally occurring therapeutic agents. CloQ is a Mg(2+)-independent aromatic prenyltransferase (APTase) that transfers a dimethylallyl group to 4-hydroxyphenylpyruvate in the biosynthetic pathway for clorobiocin. APTases consist of a common ABBA fold that defines a β-barrel containing the reaction cavity. Positively charged basic residues line the inside of the β-barrel of CloQ to activate the pyrophosphate leaving group to replace the function of the Mg(2+) cofactor in other APTases. Classical molecular dynamics simulations of CloQ, its E281G and F68S mutants, and the related NovQ were used to explore the binding of the 4-hydroxyphenylpyruvate (4HPP) and dimethylallyl diphosphate substrates in the reactive cavity and the role of various conserved residues. Hybrid quantum mechanics/molecular mechanics potential of mean force (PMF) calculations show that the effect of the replacement of the Mg(2+) cofactor with basic residues yields a similar activation barrier for prenylation to Mg(2+)-dependent APTases like NphB. The topology of the binding pocket for 4HPP is important for selective prenylation at the ortho position of the ring. Methylation at this position alters the conformation of the substrate for O-prenylation at the phenol group. Further, a two-dimensional PMF scan shows that a "reverse" prenylation product may be a possible target for protein engineering.
International Nuclear Information System (INIS)
Arunasalam, V.
1989-05-01
World space mapping in inertial frames is used to examine the Lorentz covariance of symmetry operations. It is found that the Galilean invariant concepts of simultaneity (S), parity (P), and time reversal symmetry (T) are not Lorentz covariant concepts for inertial observers. That is, just as the concept of simultaneity has no significance independent of the Lorentz inertial frame, likewise so are the concepts of parity and time reversal. However, the world parity (W) [i.e., the space-time reversal symmetry (P-T)] is a truly Lorentz covariant concept. Indeed, it is shown that only those mapping matrices M that commute with the Lorentz transformation matrix L (i.e., [M,L] = 0) are the ones that correspond to manifestly Lorentz covariant operations. This result is in accordance with the spirit of the world space Mach's principle. Since the Lorentz transformation is an orthogonal transformation while the Galilean transformation is not an orthogonal transformation, the formal relativistic space-time mapping theory used here does not have a corresponding non-relativistic counterpart. 12 refs
A generalization of Fermat's principle for classical and quantum systems
Elsayed, Tarek A.
2014-09-01
The analogy between dynamics and optics had a great influence on the development of the foundations of classical and quantum mechanics. We take this analogy one step further and investigate the validity of Fermat's principle in many-dimensional spaces describing dynamical systems (i.e., the quantum Hilbert space and the classical phase and configuration space). We propose that if the notion of a metric distance is well defined in that space and the velocity of the representative point of the system is an invariant of motion, then a generalized version of Fermat's principle will hold. We substantiate this conjecture for time-independent quantum systems and for a classical system consisting of coupled harmonic oscillators. An exception to this principle is the configuration space of a charged particle in a constant magnetic field; in this case the principle is valid in a frame rotating by half the Larmor frequency, not the stationary lab frame.
DEFF Research Database (Denmark)
Lemvig, Jakob; Miller, Christopher; Okoudjou, Kasso A.
2014-01-01
to suggest effective analysis and synthesis computation strategies for such frames. Finally, we describe all prime frames constructed from the spectral tetris method, and, as a byproduct, we obtain a characterization of when the spectral tetris construction works for redundancies below two.......We introduce a class of finite tight frames called prime tight frames and prove some of their elementary properties. In particular, we show that any finite tight frame can be written as a union of prime tight frames. We then characterize all prime harmonic tight frames and use thischaracterization...
Framing of health information messages.
Akl, Elie A; Oxman, Andrew D; Herrin, Jeph; Vist, Gunn E; Terrenato, Irene; Sperati, Francesca; Costiniuk, Cecilia; Blank, Diana; Schünemann, Holger
2011-12-07
The same information about the evidence on health effects can be framed either in positive words or in negative words. Some research suggests that positive versus negative framing can lead to different decisions, a phenomenon described as the framing effect. Attribute framing is the positive versus negative description of a specific attribute of a single item or a state, for example, "the chance of survival with cancer is 2/3" versus "the chance of mortality with cancer is 1/3". Goal framing is the description of the consequences of performing or not performing an act as a gain versus a loss, for example, "if you undergo a screening test for cancer, your survival will be prolonged" versus "if you don't undergo screening test for cancer, your survival will be shortened". To evaluate the effects of attribute (positive versus negative) framing and of goal (gain versus loss) framing of the same health information, on understanding, perception of effectiveness, persuasiveness, and behavior of health professionals, policy makers, and consumers. We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, issue 3 2007), MEDLINE (Ovid) (1966 to October 2007), EMBASE (Ovid) (1980 to October 2007), PsycINFO (Ovid) (1887 to October 2007). There were no language restrictions. We reviewed the reference lists of related systematic reviews, included studies and of excluded but closely related studies. We also contacted experts in the field. We included randomized controlled trials, quasi-randomised controlled trials, and cross-over studies with health professionals, policy makers, and consumers evaluating one of the two types of framing. Two review authors extracted data in duplicate and independently. We graded the quality of evidence for each outcome using the GRADE approach. We standardized the outcome effects using standardized mean difference (SMD). We stratified the analysis by the type of framing (attribute, goal) and conducted pre
Expected number of quantum channels in quantum networks
Chen, Xi; Wang, He-Ming; Ji, Dan-Tong; Mu, Liang-Zhu; Fan, Heng
2015-07-01
Quantum communication between nodes in quantum networks plays an important role in quantum information processing. Here, we proposed the use of the expected number of quantum channels as a measure of the efficiency of quantum communication for quantum networks. This measure quantified the amount of quantum information that can be teleported between nodes in a quantum network, which differs from classical case in that the quantum channels will be consumed if teleportation is performed. We further demonstrated that the expected number of quantum channels represents local correlations depicted by effective circles. Significantly, capacity of quantum communication of quantum networks quantified by ENQC is independent of distance for the communicating nodes, if the effective circles of communication nodes are not overlapped. The expected number of quantum channels can be enhanced through transformations of the lattice configurations of quantum networks via entanglement swapping. Our results can shed lights on the study of quantum communication in quantum networks.
Making students' frames explicit
DEFF Research Database (Denmark)
Nielsen, Louise Møller; Hansen, Poul Henrik Kyvsgaard
2016-01-01
Framing is a vital part of the design and innovation process. Frames are cognitive shortcuts (i.e. metaphors) that enable designers to connect insights about i.e. market opportunities and users needs with a set of solution principles and to test if this connection makes sense. Until now, framing...
Skopina, Maria; Protasov, Vladimir
2016-01-01
This book presents a systematic study of multivariate wavelet frames with matrix dilation, in particular, orthogonal and bi-orthogonal bases, which are a special case of frames. Further, it provides algorithmic methods for the construction of dual and tight wavelet frames with a desirable approximation order, namely compactly supported wavelet frames, which are commonly required by engineers. It particularly focuses on methods of constructing them. Wavelet bases and frames are actively used in numerous applications such as audio and graphic signal processing, compression and transmission of information. They are especially useful in image recovery from incomplete observed data due to the redundancy of frame systems. The construction of multivariate wavelet frames, especially bases, with desirable properties remains a challenging problem as although a general scheme of construction is well known, its practical implementation in the multidimensional setting is difficult. Another important feature of wavelet is ...
Changing climate, changing frames
International Nuclear Information System (INIS)
Vink, Martinus J.; Boezeman, Daan; Dewulf, Art; Termeer, Catrien J.A.M.
2013-01-01
Highlights: ► We show development of flood policy frames in context of climate change attention. ► Rising attention on climate change influences traditional flood policy framing. ► The new framing employs global-scale scientific climate change knowledge. ► With declining attention, framing disregards climate change, using local knowledge. ► We conclude that frames function as sensemaking devices selectively using knowledge. -- Abstract: Water management and particularly flood defence have a long history of collective action in low-lying countries like the Netherlands. The uncertain but potentially severe impacts of the recent climate change issue (e.g. sea level rise, extreme river discharges, salinisation) amplify the wicked and controversial character of flood safety policy issues. Policy proposals in this area generally involve drastic infrastructural works and long-term investments. They face the difficult challenge of framing problems and solutions in a publicly acceptable manner in ever changing circumstances. In this paper, we analyse and compare (1) how three key policy proposals publicly frame the flood safety issue, (2) the knowledge referred to in the framing and (3) how these frames are rhetorically connected or disconnected as statements in a long-term conversation. We find that (1) framings of policy proposals differ in the way they depict the importance of climate change, the relevant timeframe and the appropriate governance mode; (2) knowledge is selectively mobilised to underpin the different frames and (3) the frames about these proposals position themselves against the background of the previous proposals through rhetorical connections and disconnections. Finally, we discuss how this analysis hints at the importance of processes of powering and puzzling that lead to particular framings towards the public at different historical junctures
DEFF Research Database (Denmark)
Mannervik, M; Fan, S; Ström, A C
1999-01-01
of the viral E4 open reading frame 4 (E4-ORF4) protein. This effect does not to require the retinoblastoma protein that previously has been shown to regulate E2F activity. The inhibitory activity of E4-ORF4 appears to be specific because E4-ORF4 had little effect on, for example, E4-ORF6/7 transactivation......Previous studies have shown that the cell cycle-regulated E2F transcription factor is subjected to both positive and negative control by phosphorylation. Here we show that in transient transfection experiments, adenovirus E1A activation of the viral E2 promoter is abrogated by coexpression...... of the E2 promoter. We further show that the repressive effect of E4-ORF4 on E2 transcription works mainly through the E2F DNA-binding sites in the E2 promoter. In agreement with this, we find that E4-ORF4 inhibits E2F-1/DP-1-mediated transactivation. We also show that E4-ORF4 inhibits E2 mRNA expression...
Frame on frames: an annotated bibliography
International Nuclear Information System (INIS)
Wright, T.; Tsao, H.J.
1983-01-01
The success or failure of any sample survey of a finite population is largely dependent upon the condition and adequacy of the list or frame from which the probability sample is selected. Much of the published survey sampling related work has focused on the measurement of sampling errors and, more recently, on nonsampling errors to a lesser extent. Recent studies on data quality for various types of data collection systems have revealed that the extent of the nonsampling errors far exceeds that of the sampling errors in many cases. While much of this nonsampling error, which is difficult to measure, can be attributed to poor frames, relatively little effort or theoretical work has focused on this contribution to total error. The objective of this paper is to present an annotated bibliography on frames with the hope that it will bring together, for experimenters, a number of suggestions for action when sampling from imperfect frames and that more attention will be given to this area of survey methods research
Modern frame structure buildings
Directory of Open Access Journals (Sweden)
В. М. Першаков
2013-07-01
Full Text Available The article deals with the design, construction and implementation of reinforced concrete frame structures with span 18, 21 m for agricultural production buildings, hall-premises of public buildings and buildings of agricultural aviation. Structures are prefabricated frame buildings and have such advantages as large space inside the structure and lower cost compared with other facilities with same purpose
Multimodal news framing effects
Powell, T.E.
2017-01-01
Visuals in news media play a vital role in framing citizens’ political preferences. Yet, compared to the written word, visual images are undervalued in political communication research. Using framing theory, this thesis redresses the balance by studying the combined, or multimodal, effects of visual
Edwards, Michael Todd; Cox, Dana C.
2011-01-01
In this article, the authors explore framing, a non-multiplicative technique commonly employed by students as they construct similar shapes. When students frame, they add (or subtract) a "border" of fixed width about a geometric object. Although the approach does not yield similar shapes in general, the mathematical underpinnings of…
Jorissen, A.J.M.; Hamer, den J.; Leijten, A.J.M.; Salenikovich, A.
2014-01-01
Due to new possibilities traditional timber framing has become increasingly popular since the beginning of the 21e century. Although traditional timber framing has been used for centuries, the expected mechanical behaviour is not dealt with in great detail in building codes, guidelines or text
Einstein and Jordan frames reconciled: A frame-invariant approach to scalar-tensor cosmology
International Nuclear Information System (INIS)
Catena, Riccardo; Pietroni, Massimo; Scarabello, Luca
2007-01-01
Scalar-tensor theories of gravity can be formulated in different frames, most notably, the Einstein and the Jordan one. While some debate still persists in the literature on the physical status of the different frames, a frame transformation in scalar-tensor theories amounts to a local redefinition of the metric, and then should not affect physical results. We analyze the issue in a cosmological context. In particular, we define all the relevant observables (redshift, distances, cross sections, ...) in terms of frame-independent quantities. Then, we give a frame-independent formulation of the Boltzmann equation, and outline its use in relevant examples such as particle freeze-out and the evolution of the cosmic microwave background photon distribution function. Finally, we derive the gravitational equations for the frame-independent quantities at first order in perturbation theory. From a practical point of view, the present approach allows the simultaneous implementation of the good aspects of the two frames in a clear and straightforward way
Information flow in quantum teleportation
Indian Academy of Sciences (India)
Home; Journals; Pramana – Journal of Physics; Volume 59; Issue 2. Information ﬂow in quantum teleportation ... Quantum information; quantum teleportation; parameter independence. Abstract. The ﬂow of information is discussed in the context of quantum teleportation. Situations are described which use a sequence of ...
Framing effects over time: comparing affective and cognitive news frames
Lecheler, S.; Matthes, J.
2012-01-01
A growing number of scholars examine the duration of framing effects. However, duration is likely to differ from frame to frame, depending on how strong a frame is. This strength is likely to be enhanced by adding emotional components to a frame. By means of an experimental survey design (n = 111),
Directory of Open Access Journals (Sweden)
Hyunsun Catherine Yoon
2017-08-01
Full Text Available This paper examines the way in which news about Gangnam Style was framed in the Korean press. First released on 15th July 2012, it became the first video to pass two billion views on YouTube. 400 news articles between July 2012 and March 2013 from two South Korean newspapers - Chosun Ilbo and Hankyoreh were analyzed using the frame analysis method in five categories: industry/economy, globalization, cultural interest, criticism, and competition. The right-left opinion cleavage is important because news frames interact with official discourses, audience frames and prior knowledge which consequently mediate effects on public opinion, policy debates, social movement and individual interpretations. Whilst the existing literature on Gangnam Style took rather holistic approach, this study aimed to fill the lacuna, considering this phenomenon as a dynamic process, by segmenting different stages - recognition, spread, peak and continuation. Both newspapers acknowledged Gangnam Style was an epochal event but their perspectives and news frames were different; globalization frame was most frequently used in Chosun Ilbo whereas cultural interest frame was most often used in Hankyoreh. Although more critical approaches were found in Hankyoreh, reflecting the right-left opinion cleavage, both papers lacked in critical appraisal and analysis of Gangnam Style’s reception in a broader context of the new Korean Wave.
Framing in criminal investigation
2016-01-01
Failures in criminal investigation may lead to wrongful convictions. Insight in the criminal investigation process is needed to understand how these investigative failures may rise and how measures can contribute to the prevention of this kind of failures. Some of the main findings of an empirical study of the criminal investigation process in four cases of major investigations are presented here. This criminal investigation process is analyzed as a process of framing, using Goffman's framing (Goffman, 1975) and interaction theories (Goffman, 1990). It shows that in addition to framing, other substantive and social factors affect the criminal investigation. PMID:29046594
News Media Framing of Negative Campaigning
DEFF Research Database (Denmark)
Pedersen, Rasmus Tue
2014-01-01
that news coverage of negative campaigning does apply the strategic game frame to a significantly larger degree than articles covering positive campaigning. This finding has significant implications for campaigning politicians and for scholars studying campaign and media effects.......News media coverage of election campaigns is often characterized by use of the strategic game frame and a focus on politicians’ use of negative campaigning. However, the exact relationship between these two characteristics of news coverage is largely unexplored. This article theorizes that consumer...... demand and norms of journalistic independence might induce the news media outlets to cover negative campaigning with a strategic game frame. A comprehensive content analysis based on several newspaper types, several election campaigns, and several different measurements of media framing confirms...
Global Vertical Reference Frame
Czech Academy of Sciences Publication Activity Database
Burša, Milan; Kenyon, S.; Kouba, J.; Šíma, Zdislav; Vatrt, V.; Vojtíšková, M.
2004-01-01
Roč. 33, - (2004), s. 404-407 ISSN 1436-3445 Institutional research plan: CEZ:AV0Z1003909 Keywords : geopotential WO * vertical systems * global vertical frame Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics
International Nuclear Information System (INIS)
Lin, S.-Y.; Chang, K.-P.; Hsieh, M.-S.; Ueng, S.-H.; Hao, S.-P.; Tseng, C.-K.; Pai, P.-C.; Chang, F.-T.; Tsai, M.-H.; Tsang, N.-M.
2005-01-01
Purpose: The presence of Epstein-Barr virus latent membrane protein-1 (LMP-1) gene in nasopharyngeal swabs indicates the presence of nasopharyngeal carcinoma (NPC) mucosal tumor cells. This study was undertaken to investigate whether the time taken for LMP-1 to disappear after initiation of primary radiotherapy (RT) was inversely associated with NPC local control. Methods and Materials: During July 1999 and October 2002, there were 127 nondisseminated NPC patients receiving serial examinations of nasopharyngeal swabbing with detection of LMP-1 during the RT course. The time for LMP-1 regression was defined as the number of days after initiation of RT for LMP-1 results to turn negative. The primary outcome was local control, which was represented by freedom from local recurrence. Results: The time for LMP-1 regression showed a statistically significant influence on NPC local control both univariately (p < 0.0001) and multivariately (p = 0.004). In multivariate analysis, the administration of chemotherapy conferred a significantly more favorable local control (p = 0.03). Advanced T status (≥ T2b), overall treatment time of external photon radiotherapy longer than 55 days, and older age showed trends toward being poor prognosticators. The time for LMP-1 regression was very heterogeneous. According to the quartiles of the time for LMP-1 regression, we defined the pattern of LMP-1 regression as late regression if it required 40 days or more. Kaplan-Meier plots indicated that the patients with late regression had a significantly worse local control than those with intermediate or early regression (p 0.0129). Conclusion: Among the potential prognostic factors examined in this study, the time for LMP-1 regression was the most independently significant factor that was inversely associated with NPC local control
On transforms between Gabor frames and wavelet frames
DEFF Research Database (Denmark)
Christensen, Ole; Goh, Say Song
2013-01-01
We describe a procedure that enables us to construct dual pairs of wavelet frames from certain dual pairs of Gabor frames. Applying the construction to Gabor frames generated by appropriate exponential Bsplines gives wavelet frames generated by functions whose Fourier transforms are compactly...... supported splines with geometrically distributed knot sequences. There is also a reverse transform, which yields pairs of dual Gabor frames when applied to certain wavelet frames....
Physics of Non-Inertial Reference Frames
International Nuclear Information System (INIS)
Kamalov, Timur F.
2010-01-01
Physics of non-inertial reference frames is a generalizing of Newton's laws to any reference frames. It is the system of general axioms for classical and quantum mechanics. The first, Kinematics Principle reads: the kinematic state of a body free of forces conserves and equal in absolute value to an invariant of the observer's reference frame. The second, Dynamics Principle extended Newton's second law to non-inertial reference frames and also contains additional variables there are higher derivatives of coordinates. Dynamics Principle reads: a force induces a change in the kinematic state of the body and is proportional to the rate of its change. It is mean that if the kinematic invariant of the reference frame is n-th derivative with respect the time, then the dynamics of a body being affected by the force F is described by the 2n-th differential equation. The third, Statics Principle reads: the sum of all forces acting a body at rest is equal to zero.
Quantum signatures of chaos or quantum chaos?
Energy Technology Data Exchange (ETDEWEB)
Bunakov, V. E., E-mail: bunakov@VB13190.spb.edu [St. Petersburg State University (Russian Federation)
2016-11-15
A critical analysis of the present-day concept of chaos in quantum systems as nothing but a “quantum signature” of chaos in classical mechanics is given. In contrast to the existing semi-intuitive guesses, a definition of classical and quantum chaos is proposed on the basis of the Liouville–Arnold theorem: a quantum chaotic system featuring N degrees of freedom should have M < N independent first integrals of motion (good quantum numbers) specified by the symmetry of the Hamiltonian of the system. Quantitative measures of quantum chaos that, in the classical limit, go over to the Lyapunov exponent and the classical stability parameter are proposed. The proposed criteria of quantum chaos are applied to solving standard problems of modern dynamical chaos theory.
Quantum signatures of chaos or quantum chaos?
International Nuclear Information System (INIS)
Bunakov, V. E.
2016-01-01
A critical analysis of the present-day concept of chaos in quantum systems as nothing but a “quantum signature” of chaos in classical mechanics is given. In contrast to the existing semi-intuitive guesses, a definition of classical and quantum chaos is proposed on the basis of the Liouville–Arnold theorem: a quantum chaotic system featuring N degrees of freedom should have M < N independent first integrals of motion (good quantum numbers) specified by the symmetry of the Hamiltonian of the system. Quantitative measures of quantum chaos that, in the classical limit, go over to the Lyapunov exponent and the classical stability parameter are proposed. The proposed criteria of quantum chaos are applied to solving standard problems of modern dynamical chaos theory.
Weaving Hilbert space fusion frames
Neyshaburi, Fahimeh Arabyani; Arefijamaal, Ali Akbar
2018-01-01
A new notion in frame theory, so called weaving frames has been recently introduced to deal with some problems in signal processing and wireless sensor networks. Also, fusion frames are an important extension of frames, used in many areas especially for wireless sensor networks. In this paper, we survey the notion of weaving Hilbert space fusion frames. This concept can be had potential applications in wireless sensor networks which require distributed processing using different fusion frames...
Rae, Alastair I M
2007-01-01
PREFACESINTRODUCTION The Photoelectric Effect The Compton Effect Line Spectra and Atomic Structure De Broglie Waves Wave-Particle Duality The Rest of This Book THE ONE-DIMENSIONAL SCHRÖDINGER EQUATIONS The Time-Dependent Schrödinger Equation The Time-Independent Schrödinger Equation Boundary ConditionsThe Infinite Square Well The Finite Square Well Quantum Mechanical Tunneling The Harmonic Oscillator THE THREE-DIMENSIONAL SCHRÖDINGER EQUATIONS The Wave Equations Separation in Cartesian Coordinates Separation in Spherical Polar Coordinates The Hydrogenic Atom THE BASIC POSTULATES OF QUANTUM MEC
Nomura, Yasunori
2012-01-01
We consider the multiverse in the intrinsically quantum mechanical framework recently proposed in Refs. [1,2]. By requiring that the principles of quantum mechanics are universally valid and that physical predictions do not depend on the reference frame one chooses to describe the multiverse, we find that the multiverse state must be static---in particular, the multiverse does not have a beginning or end. We argue that, despite its naive appearance, this does not contradict observation, inclu...
Operator representations of frames
DEFF Research Database (Denmark)
Christensen, Ole; Hasannasab, Marzieh
2017-01-01
of the properties of the operator T requires more work. For example it is a delicate issue to obtain a representation with a bounded operator, and the availability of such a representation not only depends on the frame considered as a set, but also on the chosen indexing. Using results from operator theory we show......The purpose of this paper is to consider representations of frames {fk}k∈I in a Hilbert space ℋ of the form {fk}k∈I = {Tkf0}k∈I for a linear operator T; here the index set I is either ℤ or ℒ0. While a representation of this form is available under weak conditions on the frame, the analysis...... that by embedding the Hilbert space ℋ into a larger Hilbert space, we can always represent a frame via iterations of a bounded operator, composed with the orthogonal projection onto ℋ. The paper closes with a discussion of an open problem concerning representations of Gabor frames via iterations of a bounded...
International Nuclear Information System (INIS)
Konstantinidis, Anastasios C.; Olivo, Alessandro; Speller, Robert D.
2011-01-01
Purpose: The x-ray performance evaluation of digital x-ray detectors is based on the calculation of the modulation transfer function (MTF), the noise power spectrum (NPS), and the resultant detective quantum efficiency (DQE). The flat images used for the extraction of the NPS should not contain any fixed pattern noise (FPN) to avoid contamination from nonstochastic processes. The ''gold standard'' method used for the reduction of the FPN (i.e., the different gain between pixels) in linear x-ray detectors is based on normalization with an average reference flat-field. However, the noise in the corrected image depends on the number of flat frames used for the average flat image. The aim of this study is to modify the standard gain correction algorithm to make it independent on the used reference flat frames. Methods: Many publications suggest the use of 10-16 reference flat frames, while other studies use higher numbers (e.g., 48 frames) to reduce the propagated noise from the average flat image. This study quantifies experimentally the effect of the number of used reference flat frames on the NPS and DQE values and appropriately modifies the gain correction algorithm to compensate for this effect. Results: It is shown that using the suggested gain correction algorithm a minimum number of reference flat frames (i.e., down to one frame) can be used to eliminate the FPN from the raw flat image. This saves computer memory and time during the x-ray performance evaluation. Conclusions: The authors show that the method presented in the study (a) leads to the maximum DQE value that one would have by using the conventional method and very large number of frames and (b) has been compared to an independent gain correction method based on the subtraction of flat-field images, leading to identical DQE values. They believe this provides robust validation of the proposed method.
National Research Council Canada - National Science Library
Agarwal, G. S
2013-01-01
.... Focusing on applications of quantum optics, the textbook covers recent developments such as engineering of quantum states, quantum optics on a chip, nano-mechanical mirrors, quantum entanglement...
DEFF Research Database (Denmark)
Anderson, Joel; Antalikova, Radka
2014-01-01
Denmark is currently experiencing the highest immigration rate in its modern history. Population surveys indicate that negative public attitudes toward immigrants actually stem from attitudes toward their (perceived) Islamic affiliation. We used a framing paradigm to investigate the explicit...... and implicit attitudes of Christian and Atheist Danes toward targets framed as Muslims or as immigrants. The results showed that explicit and implicit attitudes were more negative when the target was framed as a Muslim, rather than as an immigrant. Interestingly, implicit attitudes were qualified...... by the participants’ religion. Specifically, analyses revealed that Christians demonstrated more negative implicit attitudes toward immigrants than Muslims. Conversely, Atheists demonstrated more negative implicit attitudes toward Muslims than Atheists. These results suggest a complex relationship between religion...
``Frames of Reference'' revisited
Steyn-Ross, Alistair; Ivey, Donald G.
1992-12-01
The PSSC teaching film, ``Frames of Reference,'' was made in 1960, and was one of the first audio-visual attempts at showing how your physical ``point of view,'' or frame of reference, necessarily alters both your perceptions and your observations of motion. The gentle humor and original demonstrations made a lasting impact on many audiences, and with its recent re-release as part of the AAPT Cinema Classics videodisc it is timely that we should review both the message and the methods of the film. An annotated script and photographs from the film are presented, followed by extension material on rotating frames which teachers may find appropriate for use in their classrooms: constructions, demonstrations, an example, and theory.
Lagerwerf, L.; Yu, L.; Baicchi, Annalisa; Pinelli, Erica
2017-01-01
Cognitive linguists suggest that metaphorical framing has strong cognitive effects. However, experimental research only showed small or contradictory effects. In this chapter, an experiment is reported in which metaphor and framing were manipulated independently. Audible political speeches were
International Nuclear Information System (INIS)
Joshi, V.M.; Agashe, Alok; Bairi, B.R.
1993-01-01
This report provides technical description regarding the Video Frame Processor (VFP) developed at Bhabha Atomic Research Centre. The instrument provides capture of video images available in CCIR format. Two memory planes each with a capacity of 512 x 512 x 8 bit data enable storage of two video image frames. The stored image can be processed on-line and on-line image subtraction can also be carried out for image comparisons. The VFP is a PC Add-on board and is I/O mapped within the host IBM PC/AT compatible computer. (author). 9 refs., 4 figs., 19 photographs
DEFF Research Database (Denmark)
Holmgreen, Lise-Lotte
Maintaining a good image and reputation in the eyes of stakeholders is vital to the organisation. Thus, in its corporate communication and discourse the organisation will seek to present or frame itself as favourably as possible while observing regulations stipulating accuracy and precision...... an organisation, and hence in shaping the image projected to the public. Framing is here understood as the selection of ‘some aspects of perceived reality … [making] them more salient in the communication text, in such a way as to promote a particular problem definition, causal interpretation, moral evaluation...
DEFF Research Database (Denmark)
Knudsen, Sanne
2017-01-01
directed at the humanities. The purpose of this study is to argue the case for further research of public understanding of the humanities and to take a first step in that direction by presenting a study of the framing of the humanities in Danish print news media. Different framings of the humanities......The humanities, the natural and social sciences all represent advanced and systematic knowledge production—and they all receive public funding for doing so. However, although the field of public understanding of science has been well established for decades, similar research attention has not been...
DEFF Research Database (Denmark)
Just, Sine Nørholm; Mouton, Nicolaas T.O.
2014-01-01
between competing frames leads to the conclusion that this political “blame game” is related to struggles over how to define the scandal, how to conceptualize its causes, and policy recommendations. Banks may have lost the battle of “Liborgate,” but the war over the meaning of financial culture is far...... from over. Originality/value – The paper is theoretically and methodologically original in its combination of the theories of framing and stasis, and it provides analytical insights into how sense is made of financial culture in the wake of the financial crisis....
DEFF Research Database (Denmark)
Hansen, Ernst Jan de Place; Brandt, Erik
2010-01-01
A ventilated cavity is usually considered good practice for removing moisture behind the cladding of timber framed walls. Timber frame walls with no cavity are a logical alternative as they are slimmer and less expensive to produce and besides the risk of a two-sided fire behind the cladding....... It was found that the specific damages made to the vapour barrier as part of the test did not have any provable effect on the moisture content. In general elements with an intact vapour barrier did not show a critical moisture content at the wind barrier after four years of exposure....
Directory of Open Access Journals (Sweden)
Sébastien Viel
Full Text Available BACKGROUND: In order to test how gravitational information would affect the choice of stable reference frame used to control posture and voluntary movement, we have analysed the forearm stabilisation during sit to stand movement under microgravity condition obtained during parabolic flights. In this study, we hypothesised that in response to the transient loss of graviceptive information, the postural adaptation might involve the use of several strategies of segmental stabilisation, depending on the subject's perceptual typology (dependence--independence with respect to the visual field. More precisely, we expected a continuum of postural strategies across subjects with 1 at one extreme the maintaining of an egocentric reference frame and 2 at the other the re-activation of childhood strategies consisting in adopting an egocentric reference frame. METHODOLOGY/PRINCIPAL FINDINGS: To check this point, a forearm stabilisation task combined with a sit to stand movement was performed with eyes closed by 11 subjects during parabolic flight campaigns. Kinematic data were collected during 1-g and 0-g periods. The postural adaptation to microgravity's constraint may be described as a continuum of strategies ranging from the use of an exo- to an egocentric reference frame for segmental stabilisation. At one extremity, the subjects used systematically an exocentric frame to control each of their body segments independently, as under normogravity conditions. At the other, the segmental stabilisation strategies consist in systematically adopting an egocentric reference frame to control their forearm's stabilisation. A strong correlation between the mode of segmental stabilisation used and the perceptual typology (dependence--independence with respect to the visual field of the subjects was reported. CONCLUSION: The results of this study show different subjects' typologies from those that use the forearm orientation in a mainly exocentric reference frame to
Frame scaling function sets and frame wavelet sets in Rd
International Nuclear Information System (INIS)
Liu Zhanwei; Hu Guoen; Wu Guochang
2009-01-01
In this paper, we classify frame wavelet sets and frame scaling function sets in higher dimensions. Firstly, we obtain a necessary condition for a set to be the frame wavelet sets. Then, we present a necessary and sufficient condition for a set to be a frame scaling function set. We give a property of frame scaling function sets, too. Some corresponding examples are given to prove our theory in each section.
Frames and extension problems I
DEFF Research Database (Denmark)
Christensen, Ole
2014-01-01
In this article we present a short survey of frame theory in Hilbert spaces. We discuss Gabor frames and wavelet frames and set the stage for a discussion of various extension principles; this will be presented in the article Frames and extension problems II (joint with H.O. Kim and R.Y. Kim)....
Sparse Matrices in Frame Theory
DEFF Research Database (Denmark)
Lemvig, Jakob; Krahmer, Felix; Kutyniok, Gitta
2014-01-01
Frame theory is closely intertwined with signal processing through a canon of methodologies for the analysis of signals using (redundant) linear measurements. The canonical dual frame associated with a frame provides a means for reconstruction by a least squares approach, but other dual frames...... yield alternative reconstruction procedures. The novel paradigm of sparsity has recently entered the area of frame theory in various ways. Of those different sparsity perspectives, we will focus on the situations where frames and (not necessarily canonical) dual frames can be written as sparse matrices...
DEFF Research Database (Denmark)
Kau, Edvin
2012-01-01
Unfolding his story very gradually and arousing the viewer’s curiosity, Sitaru invites the audience to investigate the parents’ and the boy’s mutual positions in their small flat, as well as the various layers of their conversations, through such means as framing, editing style, and the use...
DEFF Research Database (Denmark)
Haastrup, Helle Kannik
2016-01-01
How is the global media event of the Oscars localised through the talk show on Danish television? How are both the mediated film star and the special brand of Hollywood celebrity culture addressed by the cultural intermediaries in the Danish framing? These are the questions I propose to answer...
DEFF Research Database (Denmark)
Petersen, Nils Holger
2010-01-01
. In Black Angels the composer – among other well-known pieces of music – quotes the medieval dies irae sequence and the second movement of Schubert’s string quartet in D minor (D. 810). The musical and intermedial references are framed with striking modernistic sounds exploring instrumental possibilities...
Williams, Laurence; Macnaghten, Philip; Davies, Richard; Curtis, Sarah
2017-01-01
The prospect of fracking in the United Kingdom has been accompanied by significant public unease. We outline how the policy debate is being framed by UK institutional actors, finding evidence of a dominant discourse in which the policy approach is defined through a deficit model of public
National Research Council Canada - National Science Library
Saywell, John; Anastakis, Dimitry; Bryden, Penny E
2009-01-01
... the pervasive effects that federalism has on Canadian politics, economics, culture, and history, and provide a detailed framework in which to understand contemporary federalism. Written in honour of John T. Saywell's half-century of accomplished and influential scholarly work and teaching, Framing Canadian Federalism is a timely and fitting t...
Global Vertical Reference Frame
Czech Academy of Sciences Publication Activity Database
Burša, Milan; Kenyon, S.; Kouba, J.; Šíma, Zdislav; Vatrt, V.; Vojtíšková, M.
-, č. 5 (2009), s. 53-63 ISSN 1801-8483 R&D Projects: GA ČR GA205/08/0328 Institutional research plan: CEZ:AV0Z10030501 Keywords : sea surface topography * satellite altimetry * vertical frames Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics
Institutional Justification in Frames
DEFF Research Database (Denmark)
Baden, Christian; Schultz, Friederike
consensus. It extents research on framing in mass communication by applying institutional theory and Boltanski and Thévenot’s (2006) theory on justification in order to explain how the success and failure of proposed interpretations depend on the mobilization of accepted social institutions to justify...
Random subspaces for encryption based on a private shared Cartesian frame
International Nuclear Information System (INIS)
Bartlett, Stephen D.; Hayden, Patrick; Spekkens, Robert W.
2005-01-01
A private shared Cartesian frame is a novel form of private shared correlation that allows for both private classical and quantum communication. Cryptography using a private shared Cartesian frame has the remarkable property that asymptotically, if perfect privacy is demanded, the private classical capacity is three times the private quantum capacity. We demonstrate that if the requirement for perfect privacy is relaxed, then it is possible to use the properties of random subspaces to nearly triple the private quantum capacity, almost closing the gap between the private classical and quantum capacities
Inertial frames and breakthrough propulsion physics
Millis, Marc G.
2017-09-01
The term ;Breakthrough Propulsion Physics; comes from the NASA project by that name which examined non-rocket space drives, gravity control, and faster-than-light travel. The focus here is on space drives and the related unsolved physics of inertial frames. A ;space drive; is a generic term encompassing any concept for using as-yet undiscovered physics to move a spacecraft instead of existing rockets, sails, or tethers. The collective state of the art spans mostly steps 1-3 of the scientific method: defining the problem, collecting data, and forming hypotheses. The key issues include (1) conservation of momentum, (2) absence of obvious reaction mass, and (3) the net-external thrusting requirement. Relevant open problems in physics include: (1) the sources and mechanisms of inertial frames, (2) coupling of gravitation to the other fundamental forces, and (3) the nature of the quantum vacuum. Rather than following the assumption that inertial frames are an immutable, intrinsic property of space, this paper revisits Mach's Principle, where it is posited that inertia is relative to the distant surrounding matter. This perspective allows conjectures that a space drive could impart reaction forces to that matter, via some as-yet undiscovered interaction with the inertial frame properties of space. Thought experiments are offered to begin a process to derive new hypotheses. It is unknown if this line of inquiry will be fruitful, but it is hoped that, by revisiting unsolved physics from a propulsion point of view, new insights will be gained.
Spin in stationary gravitational fields and rotating frames
International Nuclear Information System (INIS)
Obukhov, Yuri N.; Silenko, Alexander J.; Teryaev, Oleg V.
2010-01-01
A spin motion of particles in stationary spacetimes is investigated in the framework of the classical gravity and relativistic quantum mechanics. We bring the Dirac equation for relativistic particles in nonstatic spacetimes to the Hamiltonian form and perform the Foldy-Wouthuysen transformation. We show the importance of the choice of tetrads for description of spin dynamics in the classical gravity. We derive classical and quantum mechanical equations of motion of the spin for relativistic particles in stationary gravitational fields and rotating frames and establish the full agreement between the classical and quantum mechanical approaches.
Banach frames for multivariate alpha-modulation spaces
DEFF Research Database (Denmark)
Borup, Lasse; Nielsen, Morten
2006-01-01
The α-modulation spaces [$Mathematical Term$], form a family of spaces that include the Besov and modulation spaces as special cases. This paper is concerned with construction of Banach frames for α-modulation spaces in the multivariate setting. The frames constructed are unions of independent Ri...... Riesz sequences based on tensor products of univariate brushlet functions, which simplifies the analysis of the full frame. We show that the multivariate α-modulation spaces can be completely characterized by the Banach frames constructed....
Are Independent Probes Truly Independent?
Camp, Gino; Pecher, Diane; Schmidt, Henk G.; Zeelenberg, Rene
2009-01-01
The independent cue technique has been developed to test traditional interference theories against inhibition theories of forgetting. In the present study, the authors tested the critical criterion for the independence of independent cues: Studied cues not presented during test (and unrelated to test cues) should not contribute to the retrieval…
Some relationship between G-frames and frames
Directory of Open Access Journals (Sweden)
Mehdi Rashidi-Kouchi
2015-06-01
Full Text Available In this paper we proved that every g-Riesz basis for Hilbert space $H$ with respect to $K$ by adding a condition is a Riesz basis for Hilbert $B(K$-module $B(H,K$. This is an extension of [A. Askarizadeh,M. A. Dehghan, {em G-frames as special frames}, Turk. J. Math., 35, (2011 1-11]. Also, we derived similar results for g-orthonormal and orthogonal bases. Some relationships between dual frame, dual g-frame and exact frame and exact g-frame are presented too.
Solid-state framing camera with multiple time frames
Energy Technology Data Exchange (ETDEWEB)
Baker, K. L.; Stewart, R. E.; Steele, P. T.; Vernon, S. P.; Hsing, W. W.; Remington, B. A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)
2013-10-07
A high speed solid-state framing camera has been developed which can operate over a wide range of photon energies. This camera measures the two-dimensional spatial profile of the flux incident on a cadmium selenide semiconductor at multiple times. This multi-frame camera has been tested at 3.1 eV and 4.5 keV. The framing camera currently records two frames with a temporal separation between the frames of 5 ps but this separation can be varied between hundreds of femtoseconds up to nanoseconds and the number of frames can be increased by angularly multiplexing the probe beam onto the cadmium selenide semiconductor.
Entanglement detection with bounded reference frames
International Nuclear Information System (INIS)
Costa, Fabio; Brukner, Caslav; Harrigan, Nicholas; Rudolph, Terry
2009-01-01
Quantum experiments usually assume the existence of perfect, classical reference frames (RFs), which allow for the specification of measurement settings (e.g. orientation of the Stern-Gerlach magnet in spin measurements) with arbitrary precision. If the RFs are 'bounded' (i.e. quantum systems themselves, having a finite number of degrees of freedom), only limited precision can be attained. Using spin coherent states as bounded RFs, we have found the minimum size needed for them to violate local realism for entangled spin systems. For composite systems of spin 1/2 particles, RFs of very small size are sufficient for the violation; however, to see this violation for macroscopic entangled spins, the size of the RF must be at least quadratically larger than that of the spins. The unavailability of such RFs gives a possible explanation for the non-observance of violation of local realism in everyday experience.
International Nuclear Information System (INIS)
Roa, Luis; Retamal, Juan Carlos; Saavedra, Carlos
2002-01-01
A proposal for a physical implementation of a quantum-state discrimination protocol using an ion in a linear trap is studied, where two nonorthogonal quantum states are codified using two electronic states of the ion. In addition, a protocol is given for discriminating superpositions of nonorthogonal entangled states between ions inside widely separated optical cavities. The discrimination protocol is extended to the case of N linearly independent nonorthogonal quantum states lying in a space of 2N-1 dimensions
International Nuclear Information System (INIS)
Bellum, J.C.; McGuire, P.
1983-01-01
We investigate forms of the molecular system Hamiltonian valid for rigorous quantum-mechanical treatments of inelastic atom--diatom collisions characterized by exchange of energy between electronic, vibrational, and rotational degrees of freedom. We analyze this Hamiltonian in terms of various choices of independent coordinates which unambiguously specify the electronic and nuclear positions in the context of space-fixed and body-fixed reference frames. In particular we derive forms of the Hamiltonian in the context of the following four sets of independent coordinates: (1) a so-called space-fixed set, in which both electronic and nuclear positions are relative to the space-fixed frame; (2) a so-called mixed set, in which nuclear positions are relative to the body-fixed frame while electronic positions are relative to the space-fixed frame; (3) a so-called body-fixed set, in which both electronic and nuclear positions are relative to the body-fixed frame; and (4) another mixed set, in which nuclear positions are relative to the space-fixed frame while electronic positions are relative to the body-fixed frame. Based on practical considerations in accounting for electronic structure and nonadiabatic coupling of electronic states of the collision complex we find the forms of the Hamiltonian in the context of coordinate sets (3) and (4) above to be most appropriate, respectively, for body-fixed and space-fixed treatments of nuclear dynamics in collisional transfer of electronic, vibrational, and rotational energies
Wavelet frames and their duals
DEFF Research Database (Denmark)
Lemvig, Jakob
2008-01-01
frames with good time localization and other attractive properties. Furthermore, the dual wavelet frames are constructed in such a way that we are guaranteed that both frames will have the same desirable features. The construction procedure works for any real, expansive dilation. A quasi-affine system....... The signals are then represented by linear combinations of the building blocks with coefficients found by an associated frame, called a dual frame. A wavelet frame is a frame where the building blocks are stretched (dilated) and translated versions of a single function; such a frame is said to have wavelet...... structure. The dilation of the wavelet building blocks in higher dimension is done via a square matrix which is usually taken to be integer valued. In this thesis we step away from the "usual" integer, expansive dilation and consider more general, expansive dilations. In most applications of wavelet frames...
Kaufman, Richard
2017-12-01
A fairly recent paper resolves a large discrepancy in the internal energy utilized to fire a cannon as calculated by two inertial observers. Earth and its small reaction velocity must be considered in the system so that the change in kinetic energy is calculated correctly. This paper uses a car in a similar scenario, but considers the work done by forces acting over distances. An analysis of the system must include all energy interactions, including the work done on the car and especially the (negative) work done on Earth in a moving reference frame. This shows the importance of considering the force on Earth and the distance Earth travels. For calculation of work in inertial reference frames, the center of mass perspective is shown to be useful. We also consider the energy requirements to efficiently accelerate a mass among interacting masses.
DEFF Research Database (Denmark)
Degel, Henrik; Jansen, Teunis
2006-01-01
. Development and test of software modules can be done once and reused by all. The biggest challenge in this is not technical – it is in organisation, coordination and trust. This challenge has been addressed by FishFrame - a web-based datawarehouse application. The “bottom-up” approach with maximum involvement...... of end users from as many labs and user groups as possible has been rather slow but quite successful in building international trust and cooperation around the system. This is mandatory prerequisites when our primary goal is not the programming project itself, but the creation of a tool that adds real...... value to users and in the end improves the way we work with our data. FishFrame version 4.2 is presented and the lessons learned from the process are discussed....
DEFF Research Database (Denmark)
Olesen, Mette
2014-01-01
In Europe, there has been a strong political will to implement light rail. This article contributes to the knowledge concerning policies around light rail by analysing how local actors frame light rail projects and which rationalities and arguments are present in this decision-making process....... The article draws on the socio-technical approach to mobilities studies in order to reassemble the decision-making process in three European cases: Bergen, Angers, and Bern. This article provides insights into the political, discursive and material production of light rail mobilities in a European context....... It identifies the planning rationales behind the systems and the policies that have been supportive of this light rail vision. Finally, the article identifies the practical challenges and potentials that have been connected to the different local frames of light rail mobility which can be used in future...
DEFF Research Database (Denmark)
Holmgreen, Lise-Lotte
2012-01-01
Danish bank, Danske Bank, during the 2008 financial crisis and hence in shaping its image projected to the public. Through the study of a number of semantic frames adopted by the Danish print press and those adopted by the Bank, this article will argue for the constructions of the press putting...... considerable strain on the Bank and its image, leading it to reconsider its previous strategy of denial of responsibility...
International Nuclear Information System (INIS)
Kalibjian, R.; Chong, Y.P.; Prono, D.S.; Cavagnolo, H.R.
1984-06-01
The ATA provides an electron beam pulse of 70-ns duration at a 1-Hz rate. Our present optical diagnostics technique involve the imaging of the visible light generated by the beam incident onto the plant of a thin sheet of material. It has already been demonstrated that the light generated has a sufficiently fast temporal reponse in performing beam diagnostics. Notwithstanding possible beam emittance degradation due to scattering in the thin sheet, the observation of beam spatial profiles with relatively high efficiencies has provided data complementary to that obtained from beam wall current monitors and from various x-ray probes and other electrical probes. The optical image sensor consists of a gated, intensified television system. The gate pulse of the image intensifier can be appropriately delayed to give frames that are time-positioned from the head to the tail of the beam with a minimum gate time of 5-ns. The spatial correlation of the time frames from pulse to pulse is very good for a stable electron beam; however, when instabilities do occur, it is difficult to properly assess the spatial composition of the head and the tail of the beam on a pulse-to-pulse basis. Multiple gating within a pulse duration becomes desirable but cannot be performed because the recycle time (20-ms) of the TV system is much longer than the beam pulse. For this reason we have developed an optical-loop framing technique that will allow the recording of two frames within one pulse duration with our present gated/intensified TV system
DEFF Research Database (Denmark)
Christensen, Ole; Heil, C.; Deng, B.
1997-01-01
A Gabor system is a set of time-frequency shifts$S(g,\\Lambda) = \\{e^{2\\pi i b x} g(x-a)\\}_{(a,b) \\in \\Lambda}$of a function $g \\in L^2({\\bold R}^d)$.We prove that if a finite union of Gabor systems$\\bigcup_{k=1}^r S(g_k,\\Lambda_k)$, with arbitrary sequences $\\Lambda_k$,forms a frame for $L^2({\\bo...
Barasz, Kate; John, Leslie K; Keenan, Elizabeth A; Norton, Michael I
2017-10-01
Pseudo-set framing-arbitrarily grouping items or tasks together as part of an apparent "set"-motivates people to reach perceived completion points. Pseudo-set framing changes gambling choices (Study 1), effort (Studies 2 and 3), giving behavior (Field Data and Study 4), and purchase decisions (Study 5). These effects persist in the absence of any reward, when a cost must be incurred, and after participants are explicitly informed of the arbitrariness of the set. Drawing on Gestalt psychology, we develop a conceptual account that predicts what will-and will not-act as a pseudo-set, and defines the psychological process through which these pseudo-sets affect behavior: over and above typical reference points, pseudo-set framing alters perceptions of (in)completeness, making intermediate progress seem less complete. In turn, these feelings of incompleteness motivate people to persist until the pseudo-set has been fulfilled. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
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)
Layered Architecture for Quantum Computing
Directory of Open Access Journals (Sweden)
N. Cody Jones
2012-07-01
Full Text Available We develop a layered quantum-computer architecture, which is a systematic framework for tackling the individual challenges of developing a quantum computer while constructing a cohesive device design. We discuss many of the prominent techniques for implementing circuit-model quantum computing and introduce several new methods, with an emphasis on employing surface-code quantum error correction. In doing so, we propose a new quantum-computer architecture based on optical control of quantum dots. The time scales of physical-hardware operations and logical, error-corrected quantum gates differ by several orders of magnitude. By dividing functionality into layers, we can design and analyze subsystems independently, demonstrating the value of our layered architectural approach. Using this concrete hardware platform, we provide resource analysis for executing fault-tolerant quantum algorithms for integer factoring and quantum simulation, finding that the quantum-dot architecture we study could solve such problems on the time scale of days.
Quantum Erasure: Quantum Interference Revisited
Walborn, Stephen P.; Cunha, Marcelo O. Terra; Pádua, Sebastião; Monken, Carlos H.
2005-01-01
Recent experiments in quantum optics have shed light on the foundations of quantum physics. Quantum erasers - modified quantum interference experiments - show that quantum entanglement is responsible for the complementarity principle.
Attribute Framing and Goal Framing Effects in Health Decisions.
Krishnamurthy, Parthasarathy; Carter, Patrick; Blair, Edward
2001-07-01
Levin, Schneider, and Gaeth (LSG, 1998) have distinguished among three types of framing-risky choice, attribute, and goal framing-to reconcile conflicting findings in the literature. In the research reported here, we focus on attribute and goal framing. LSG propose that positive frames should be more effective than negative frames in the context of attribute framing, and negative frames should be more effective than positive frames in the context of goal framing. We test this framework by manipulating frame valence (positive vs negative) and frame type (attribute vs goal) in a unified context with common procedures. We also argue that the nature of effects in a goal-framing context may depend on the extent to which the research topic has "intrinsic self-relevance" to the population. In the context of medical decision making, we operationalize low intrinsic self-relevance by using student subjects and high intrinsic self-relevance by using patients. As expected, we find complete support for the LSG framework under low intrinsic self-relevance and modified support for the LSG framework under high intrinsic self-relevance. Overall, our research appears to confirm and extend the LSG framework. Copyright 2001 Academic Press.
Conformal frame dependence of inflation
International Nuclear Information System (INIS)
Domènech, Guillem; Sasaki, Misao
2015-01-01
Physical equivalence between different conformal frames in scalar-tensor theory of gravity is a known fact. However, assuming that matter minimally couples to the metric of a particular frame, which we call the matter Jordan frame, the matter point of view of the universe may vary from frame to frame. Thus, there is a clear distinction between gravitational sector (curvature and scalar field) and matter sector. In this paper, focusing on a simple power-law inflation model in the Einstein frame, two examples are considered; a super-inflationary and a bouncing universe Jordan frames. Then we consider a spectator curvaton minimally coupled to a Jordan frame, and compute its contribution to the curvature perturbation power spectrum. In these specific examples, we find a blue tilt at short scales for the super-inflationary case, and a blue tilt at large scales for the bouncing case
... URL of this page: https://medlineplus.gov/faq/framing.html I'd like to link to MedlinePlus, ... M. encyclopedia. Our license agreements do not permit framing of their content from our site. For more ...
Conformal frame dependence of inflation
Energy Technology Data Exchange (ETDEWEB)
Domènech, Guillem; Sasaki, Misao, E-mail: guillem.domenech@yukawa.kyoto-u.ac.jp, E-mail: misao@yukawa.kyoto-u.ac.jp [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan)
2015-04-01
Physical equivalence between different conformal frames in scalar-tensor theory of gravity is a known fact. However, assuming that matter minimally couples to the metric of a particular frame, which we call the matter Jordan frame, the matter point of view of the universe may vary from frame to frame. Thus, there is a clear distinction between gravitational sector (curvature and scalar field) and matter sector. In this paper, focusing on a simple power-law inflation model in the Einstein frame, two examples are considered; a super-inflationary and a bouncing universe Jordan frames. Then we consider a spectator curvaton minimally coupled to a Jordan frame, and compute its contribution to the curvature perturbation power spectrum. In these specific examples, we find a blue tilt at short scales for the super-inflationary case, and a blue tilt at large scales for the bouncing case.
Group Frames With Few Distinct Inner Products and Low Coherence
Thill, Matthew
2015-10-01
Frame theory has been a popular subject in the design of structured signals and codes in recent years, with applications ranging from the design of measurement matrices in compressive sensing, to spherical codes for data compression and data transmission, to spacetime codes for MIMO communications, and to measurement operators in quantum sensing. High-performance codes usually arise from designing frames whose elements have mutually low coherence. Building off the original “group frame” design of Slepian which has since been elaborated in the works of Vale and Waldron, we present several new frame constructions based on cyclic and generalized dihedral groups. Slepian\\'s original construction was based on the premise that group structure allows one to reduce the number of distinct inner pairwise inner products in a frame with n elements from [(n(n-1))/2] to n-1. All of our constructions further utilize the group structure to produce tight frames with even fewer distinct inner product values between the frame elements. When n is prime, for example, we use cyclic groups to construct m-dimensional frame vectors with at most [(n-1)/m] distinct inner products. We use this behavior to bound the coherence of our frames via arguments based on the frame potential, and derive even tighter bounds from combinatorial and algebraic arguments using the group structure alone. In certain cases, we recover well-known Welch bound achieving frames. In cases where the Welch bound has not been achieved, and is not known to be achievable, we obtain frames with close to Welch bound performance.
Frames in super Hilbert modules
Directory of Open Access Journals (Sweden)
Mehdi Rashidi-Kouchi
2018-01-01
Full Text Available In this paper, we define super Hilbert module and investigate frames in this space. Super Hilbert modules are generalization of super Hilbert spaces in Hilbert C*-module setting. Also, we define frames in a super Hilbert module and characterize them by using of the concept of g-frames in a Hilbert C*-module. Finally, disjoint frames in Hilbert C*-modules are introduced and investigated.
A question mark on the equivalence of Einstein and Jordan frames
Directory of Open Access Journals (Sweden)
Narayan Banerjee
2016-03-01
Full Text Available With an explicit example, we show that Jordan frame and the conformally transformed Einstein frames clearly lead to different physics for a non-minimally coupled theory of gravity, namely Brans–Dicke theory, at least at the quantum level. The example taken up is the spatially flat Friedmann cosmology in Brans–Dicke theory.
A question mark on the equivalence of Einstein and Jordan frames
Energy Technology Data Exchange (ETDEWEB)
Banerjee, Narayan [Department of Physical Sciences, Indian Institute of Science Education and Research - Kolkata, West Bengal 741246 (India); Majumder, Barun, E-mail: barunbasanta@iitgn.ac.in [Department of Physics, Montana State University, Bozeman, MT 59717 (United States); Department of Physics, IIT Gandhinagar, Ahmedabad (India)
2016-03-10
With an explicit example, we show that Jordan frame and the conformally transformed Einstein frames clearly lead to different physics for a non-minimally coupled theory of gravity, namely Brans–Dicke theory, at least at the quantum level. The example taken up is the spatially flat Friedmann cosmology in Brans–Dicke theory.
New avenues for framing research
de Vreese, C.H.
2012-01-01
In this article, the author reviews the studies in this special issue of the American Behavioral Scientist. It is a strong collection of articles reporting findings from an integrated project that looks at frame building, frames, and effects of frames. The project is part of an exciting large-scale
Energy Technology Data Exchange (ETDEWEB)
Sanfilippo, Antonio P.; McGrath, Liam R.; Whitney, Paul D.
2011-11-17
We present a computational approach to radical rhetoric that leverages the co-expression of rhetoric and action features in discourse to identify violent intent. The approach combines text mining and machine learning techniques with insights from Frame Analysis and theories that explain the emergence of violence in terms of moral disengagement, the violation of sacred values and social isolation in order to build computational models that identify messages from terrorist sources and estimate their proximity to an attack. We discuss a specific application of this approach to a body of documents from and about radical and terrorist groups in the Middle East and present the results achieved.
Continuous Shearlet Tight Frames
Grohs, Philipp
2010-10-22
Based on the shearlet transform we present a general construction of continuous tight frames for L2(ℝ2) from any sufficiently smooth function with anisotropic moments. This includes for example compactly supported systems, piecewise polynomial systems, or both. From our earlier results in Grohs (Technical report, KAUST, 2009) it follows that these systems enjoy the same desirable approximation properties for directional data as the previous bandlimited and very specific constructions due to Kutyniok and Labate (Trans. Am. Math. Soc. 361:2719-2754, 2009). We also show that the representation formulas we derive are in a sense optimal for the shearlet transform. © 2010 Springer Science+Business Media, LLC.
Fundamentals of quantum information
International Nuclear Information System (INIS)
Zeilinger, A.
1998-01-01
The fact that information is physical means that the laws of quantum mechanics can be used to process and transmit it in ways that are not possible with existing systems. Ever since its invention in the 1920s, quantum physics has given rise to countless discussions about its meaning and about how to interpret the theory correctly. These discussions focus on issues like the Einstein-Podolsky-Rosen paradox, quantum non-locality and the role of measurement in quantum physics. In recent years, however, research into the very foundations of quantum mechanics has also led to a new field quantum information technology. The use of quantum physics could revolutionize the way we communicate and process information. The important new observation is that information is not independent of the physical laws used to store and processes it (see Landauer in further reading). Although modern computers rely on quantum mechanics to operate, the information itself is still encoded classically. A new approach is to treat information as a quantum concept and to ask what new insights can be gained by encoding this information in individual quantum systems. In other words, what happens when both the transmission and processing of information are governed by quantum laws? (UK)
Integrated Broadband Quantum Cascade Laser
Mansour, Kamjou (Inventor); Soibel, Alexander (Inventor)
2016-01-01
A broadband, integrated quantum cascade laser is disclosed, comprising ridge waveguide quantum cascade lasers formed by applying standard semiconductor process techniques to a monolithic structure of alternating layers of claddings and active region layers. The resulting ridge waveguide quantum cascade lasers may be individually controlled by independent voltage potentials, resulting in control of the overall spectrum of the integrated quantum cascade laser source. Other embodiments are described and claimed.
Directory of Open Access Journals (Sweden)
Eulàlia P. Abril
2014-01-01
Full Text Available En respuesta a la enorme y algunas veces conceptualmente inconsistente literatura sobre valence framing,Levin y sus colegas (1998 desarrollaron una tipología de encuadre de valencia que organiza los diferentesresultados a partir de elección arriesgada, atributo, y encuadre de los resultados (goal framing. Este estudiofavorece la literatura sobre encuadre de los resultados mediante (a su aplicación en el contexto de una cuestiónsocial como la pobreza infantil extrema; y (b el examen de los mecanismos afectivos sobre el cual el encuadrede los resultados es de eficacia persuasiva. Los resultados experimentales (N = 197 mostraron que la exposiciónal mensaje de encuadre de pérdida permitió un apoyo mayor hacia las políticas públicas que buscan erradicar lapobreza infantil, en comparación con el mensaje de encuadre de ganancia. Los resultados también revelaronque el afecto negativo sirve como herramienta mediadora de apoyo hacia las políticas públicas. Estos hallazgossugieren que, en el contexto del apoyo social hacia la población pobre, la capacidad de persuasión dentro delencuadre de pérdida se facilita cuando los participantes experimentan afectos negativos.
Directory of Open Access Journals (Sweden)
I Nyoman Aryawibawa
2016-04-01
Full Text Available Abstract: Balinese Frame of Reference. Wassmann and Dasen (1998 did a study on the acquisition of Balinese frames of reference. They pointed out that, in addition to the dominant use of absolute system, the use of relative system was also observed. This article aims at verifying Wassmann and Dasen’ study. Employing monolingual Balinese speakers and using linguistic and non-linguistic tasks, Aryawibawa (2010, 2012, 2015 showed that Balinese subjects used an absolute system dominantly in responding the two tasks, e.g. The man is north/south/east/west of the car. Unlike Wassmann and Dasen’s results, no relative system was used by the subjects in solving the tasks. Instead of the relative system, an intrinsic system was also observed in this study, even though it was unfrequent. The article concludes that the absolute system was dominantly employed by Balinese speakers in describing spatial relations in Balinese. The use of the system seems to affect their cognitive functions.
Huhn, John M; Potts, Cory Adam; Rosenbaum, David A
2016-06-01
Cognitive framing effects have been widely reported in higher-level decision-making and have been ascribed to rules of thumb for quick thinking. No such demonstrations have been reported for physical action, as far as we know, but they would be expected if cognition for physical action is fundamentally similar to cognition for higher-level decision-making. To test for such effects, we asked participants to reach for a horizontally-oriented pipe to move it from one height to another while turning the pipe 180° to bring one end (the "business end") to a target on the left or right. From a physical perspective, participants could have always rotated the pipe in the same angular direction no matter which end was the business end; a given participant could have always turned the pipe clockwise or counter-clockwise. Instead, our participants turned the business end counter-clockwise for left targets and clockwise for right targets. Thus, the way the identical physical task was framed altered the way it was performed. This finding is consistent with the hypothesis that cognition for physical action is fundamentally similar to cognition for higher-level decision-making. A tantalizing possibility is that higher-level decision heuristics have roots in the control of physical action, a hypothesis that accords with embodied views of cognition. Copyright © 2016 Elsevier B.V. All rights reserved.
Identifying issue frames in text.
Directory of Open Access Journals (Sweden)
Eyal Sagi
Full Text Available Framing, the effect of context on cognitive processes, is a prominent topic of research in psychology and public opinion research. Research on framing has traditionally relied on controlled experiments and manually annotated document collections. In this paper we present a method that allows for quantifying the relative strengths of competing linguistic frames based on corpus analysis. This method requires little human intervention and can therefore be efficiently applied to large bodies of text. We demonstrate its effectiveness by tracking changes in the framing of terror over time and comparing the framing of abortion by Democrats and Republicans in the U.S.
Message framing and perinatal decisions.
Haward, Marlyse F; Murphy, Ryan O; Lorenz, John M
2008-07-01
The purpose of this study was to explore the effect of information framing on parental decisions about resuscitation of extremely premature infants. Secondary outcomes focused on elucidating the impact of other variables on treatment choices and determining whether those effects would take precedence over any framing effects. This confidential survey study was administered to adult volunteers via the Internet. The surveys depicted a hypothetical vignette of a threatened delivery at gestational age of 23 weeks, with prognostic outcome information framed as either survival with lack of disability (positive frame) or chance of dying and likelihood of disability among survivors (negative frame). Participants were randomly assigned to receive either the positively or negatively framed vignette. They were then asked to choose whether they would prefer resuscitation or comfort care. After completing the survey vignette, participants were directed to a questionnaire designed to test the secondary hypothesis and to explore possible factors associated with treatment decisions. A total of 146 subjects received prognostic information framed as survival data and 146 subjects received prognostic information framed as mortality data. Overall, 24% of the sample population chose comfort care and 76% chose resuscitation. A strong trend was detected toward a framing effect on treatment preference; respondents for whom prognosis was framed as survival data were more likely to elect resuscitation. This framing effect was significant in a multivariate analysis controlling for religiousness, parental status, and beliefs regarding the sanctity of life. Of these covariates, only religiousness modified susceptibility to framing; participants who were not highly religious were significantly more likely to be influenced to opt for resuscitation by the positive frame than were participants who were highly religious. Framing bias may compromise efforts to approach prenatal counseling in a
National Research Council Canada - National Science Library
Agarwal, G. S
2013-01-01
..., quantum metrology, spin squeezing, control of decoherence and many other key topics. Readers are guided through the principles of quantum optics and their uses in a wide variety of areas including quantum information science and quantum mechanics...
DEFF Research Database (Denmark)
Holmgreen, Lise-Lotte
2013-01-01
Genres are ways for organisations of discursively interacting with the surrounding world, with the aim of achieving specific disciplinary goals (Bhatia 2004). As such, the management job ad has the objective of finding the right candidate for the management job advertised (Norlyk 2006......). In this process, framing (Evans & Green 2006; Fillmore 1982; Kövecses 2006; Lakoff 1987, 1996) plays a salient role in conceptualising the profile and qualities of the preferred candidate, drawing on established cultural models of what constitutes the perfect leader. Thus, in a Danish setting we may talk of two...... in this realisation, the fact that one of the two models, the ‘goal-oriented motivator’ model, seems to be monopolising the genre raises a number of issues that need to be addressed: How is this model realised conceptually and linguistically? Why does this model continue to be the Danish business world’s preferred...
Shield support frame. Schildausbaugestell
Energy Technology Data Exchange (ETDEWEB)
Plaga, K.
1981-09-17
A powered shield support frame for coal sheds is described comprising of two bottom sliding shoes, a large area gob shield and a larg area roof assembly, all joined movable together. The sliding shoes and the gob shield are joined by a lemniscate guide. Two hydraulic props are arranged at the face-side at one third of the length of the sliding shoes and at the goaf-side at one third of the length of the roof assembly. A nearly horizontal lying pushing prop unit joins the bottom wall sliding shoes to the goaf-side lemniscate guide. This assembly can be applied to seams with a thickness down to 45 cm. (OGR).
D´Elia, Gabriel Anibal
2000-01-01
Esta tesis trata el tema de VOFR, desde la digitalización de la voz hasta su transmisión a través de dicha red, así también como la comparación con otros medios de transporte como VOIP. Dada las características del protocolo frame relay y su disponibilidad se eligió como el medio más apropiado para la transmisión de voz y datos en forma integrada sobre una misma red. El trabajo comienza con una breve explicación de la voz, su digitalización y forma actual de transmisión a través de una red di...
Riesz frames and approximation of the frame coefficients
DEFF Research Database (Denmark)
Casazza, P.; Christensen, Ole
1998-01-01
A frame is a fmaily {f i } i=1 ∞ of elements in a Hilbert space with the property that every element in can be written as a (infinite) linear combination of the frame elements. Frame theory describes how one can choose the corresponding coefficients, which are called frame coefficients. From...... the mathematical point of view this is gratifying, but for applications it is a problem that the calculation requires inversion of an operator on . The projection method is introduced in order to avoid this problem. The basic idea is to consider finite subfamilies {f i } i=1 n of the frame and the orthogonal...... projection Pn onto its span. For has a representation as a linear combination of fi, i=1,2,..., n and the corresponding coefficients can be calculated using finite dimensional methods. We find conditions implying that those coefficients converge to the correct frame coefficients as n→∞, in which case we have...
Behaviour of Strengthened RC Frames with Eccentric Steel Braced Frames
Directory of Open Access Journals (Sweden)
Kamanli Mehmet
2017-01-01
Full Text Available After devastating earthquakes in recent years, strengthening of reinforced concrete buildings became an important research topic. Reinforced concrete buildings can be strengthened by steel braced frames. These steel braced frames may be made of concentrically or eccentrically indicated in Turkish Earthquake Code 2007. In this study pushover analysis of the 1/3 scaled 1 reinforced concrete frame and 1/3 scaled 4 strengthened reinforced concrete frames with internal eccentric steel braced frames were conducted by SAP2000 program. According to the results of the analyses conducted, load-displacement curves of the specimens were compared and evaluated. Adding eccentric steel braces to the bare frame decreased the story drift, and significantly increased strength, stiffness and energy dissipation capacity. In this strengthening method lateral load carrying capacity, stiffness and dissipated energy of the structure can be increased.
Behaviour of Strengthened RC Frames with Eccentric Steel Braced Frames
Kamanli, Mehmet; Unal, Alptug
2017-10-01
After devastating earthquakes in recent years, strengthening of reinforced concrete buildings became an important research topic. Reinforced concrete buildings can be strengthened by steel braced frames. These steel braced frames may be made of concentrically or eccentrically indicated in Turkish Earthquake Code 2007. In this study pushover analysis of the 1/3 scaled 1 reinforced concrete frame and 1/3 scaled 4 strengthened reinforced concrete frames with internal eccentric steel braced frames were conducted by SAP2000 program. According to the results of the analyses conducted, load-displacement curves of the specimens were compared and evaluated. Adding eccentric steel braces to the bare frame decreased the story drift, and significantly increased strength, stiffness and energy dissipation capacity. In this strengthening method lateral load carrying capacity, stiffness and dissipated energy of the structure can be increased.
Connecting VLBI and Gaia Celestial Reference Frames
Energy Technology Data Exchange (ETDEWEB)
Malkin, Zinovy, E-mail: malkin@gao.spb.ru [Department of Radio Astronomy Research, The Pulkovo Astronomical Observatory, St. Petersburg (Russian Federation); Institute of Earth Sciences, St. Petersburg State University, St. Petersburg (Russian Federation); Astronomy and Cosmic Geodesy Department, Kazan Federal University, Kazan (Russian Federation)
2016-09-12
The current state of the link problem between radio and optical celestial reference frames is considered. The main objectives of the investigations in this direction during the next few years are the preparation of a comparison and the mutual orientation and rotation between the optical Gaia Celestial Reference Frame (GCRF) and the 3rd generation radio International Celestial Reference Frame (ICRF3), obtained from VLBI observations. Both systems, ideally, should be a realization of the ICRS (International Celestial Reference System) at micro-arcsecond level accuracy. Therefore, the link accuracy between the ICRF and GCRF should be obtained with similar error level, which is not a trivial task due to relatively large systematic and random errors in source positions at different frequency bands. In this paper, a brief overview of recent work on the GCRF–ICRF link is presented. Additional possibilities to improve the GCRF–ICRF link accuracy are discussed. The suggestion is made to use astrometric radio sources with optical magnitude to 20{sup m} rather than to 18{sup m} as currently planned for the GCRF–ICRF link. In addition, the use of radio stars is also a prospective method to obtain independent and accurate orientation between the Gaia frame and the ICRF.
The covariance of GPS coordinates and frames
International Nuclear Information System (INIS)
Lachieze-Rey, Marc
2006-01-01
We explore, in the general relativistic context, the properties of the recently introduced global positioning system (GPS) coordinates, as well as those of the associated frames and coframes that they define. We show that they are covariant and completely independent of any observer. We show that standard spectroscopic and astrometric observations allow any observer to measure (i) the values of the GPS coordinates at his position (ii) the components of his 4-velocity and (iii) the components of the metric in the GPS frame. This provides this system with a unique value both for conceptual discussion (no frame dependence) and for practical use (involved quantities are directly measurable): localization, motion monitoring, astrometry, cosmography and tests of gravitation theories. We show explicitly, in the general relativistic context, how an observer may estimate his position and motion, and reconstruct the components of the metric. This arises from two main results: the extension of the velocity fields of the probes to the whole (curved) spacetime, and the identification of the components of the observer's velocity in the GPS frame with the (inversed) observed redshifts of the probes. Specific cases (non-relativistic velocities, Minkowski and Friedmann-Lemaitre spacetimes, geodesic motions) are studied in detail
Connecting VLBI and Gaia celestial reference frames
Directory of Open Access Journals (Sweden)
Zinovy Malkin
2016-09-01
Full Text Available The current state of the link problem between radio and optical celestial reference frames is considered.The main objectives of the investigations in this direction during the next few years are the preparation of a comparisonand the mutual orientation and rotation between the optical it Gaia Celestial Reference Frame (GCRFand the 3rd generation radio International Celestial Reference Frame (ICRF3, obtained from VLBI observations.Both systems, ideally, should be a realization of the ICRS (International Celestial Reference System at micro-arcsecond level accuracy.Therefore, the link accuracy between the ICRF and GCRF should be obtained with similar error level, which is not a trivial taskdue to relatively large systematic and random errors in source positions at different frequency bands.In this paper, a brief overview of recent work on the GCRF--ICRF link is presented.Additional possibilities to improve the GCRF--ICRF link accuracy are discussed.The suggestion is made to use astrometric radio sources with optical magnitude to 20$^m$ rather than to 18$^m$ as currently plannedfor the GCRF--ICRF link.In addition, the use of radio stars is also a prospective method to obtain independent and accurate orientation between the Gaia frame and the ICRF.
Quantum Instantons and Quantum Chaos
Jirari, H.; Kröger, H.; Luo, X. Q.; Moriarty, K. J. M.; Rubin, S. G.
1999-01-01
Based on a closed form expression for the path integral of quantum transition amplitudes, we suggest rigorous definitions of both, quantum instantons and quantum chaos. As an example we compute the quantum instanton of the double well potential.
Compton Operator in Quantum Electrodynamics
International Nuclear Information System (INIS)
Garcia, Hector Luna; Garcia, Luz Maria
2015-01-01
In the frame in the quantum electrodynamics exist four basic operators; the electron self-energy, vacuum polarization, vertex correction, and the Compton operator. The first three operators are very important by its relation with renormalized and Ward identity. However, the Compton operator has equal importance, but without divergence, and little attention has been given it. We have calculated the Compton operator and obtained the closed expression for it in the frame of dimensionally continuous integration and hypergeometric functions
International Nuclear Information System (INIS)
Xiang Guo-Yong; Guo Guang-Can
2013-01-01
The statistical error is ineluctable in any measurement. Quantum techniques, especially with the development of quantum information, can help us squeeze the statistical error and enhance the precision of measurement. In a quantum system, there are some quantum parameters, such as the quantum state, quantum operator, and quantum dimension, which have no classical counterparts. So quantum metrology deals with not only the traditional parameters, but also the quantum parameters. Quantum metrology includes two important parts: measuring the physical parameters with a precision beating the classical physics limit and measuring the quantum parameters precisely. In this review, we will introduce how quantum characters (e.g., squeezed state and quantum entanglement) yield a higher precision, what the research areas are scientists most interesting in, and what the development status of quantum metrology and its perspectives are. (topical review - quantum information)
Quantum Distinction: Quantum Distinctiones!
Zeps, Dainis
2009-01-01
10 pages; How many distinctions, in Latin, quantum distinctiones. We suggest approach of anthropic principle based on anthropic reference system which should be applied equally both in theoretical physics and in mathematics. We come to principle that within reference system of life subject of mathematics (that of thinking) should be equated with subject of physics (that of nature). For this reason we enter notions of series of distinctions, quantum distinction, and argue that quantum distinct...
DEFF Research Database (Denmark)
Christensen, Ole
2014-01-01
We discuss various problems in frame theory that have been open for some years. A short discussion of frame theory is also provided, but it only contains the information that is necessary in order to understand the open problems and their role.......We discuss various problems in frame theory that have been open for some years. A short discussion of frame theory is also provided, but it only contains the information that is necessary in order to understand the open problems and their role....
DEFF Research Database (Denmark)
Christensen, Ole; Goh, Say Song
2012-01-01
The time–frequency analysis of a signal is often performed via a series expansion arising from well-localized building blocks. Typically, the building blocks are based on frames having either Gabor or wavelet structure. In order to calculate the coefficients in the series expansion, a dual frame...... is needed. The purpose of the present paper is to provide constructions of dual pairs of frames in the setting of the Hilbert space of periodic functions L2(0,2π). The frames constructed are given explicitly as trigonometric polynomials, which allows for an efficient calculation of the coefficients...
Frames, agency and institutional change
DEFF Research Database (Denmark)
Rasmussen, Grane Mikael Gregaard; Jensen, Per Langaa; Gottlieb, Stefan Christoffer
2017-01-01
This study examines change and the sources influencing the formulation and diffusion of policies in construction. The change examined is the introduction of a benchmarking policy initiative in the Danish construction industry. Using institutional theory with emphasis on the concepts of frames...... and framings, we show how strategically motivated actors are able to frame policy problems in ways that disclose the mixture of motives, interests and institutional mechanisms at play in change processes. In doing so, we contribute to the literature on the role of agency in institutional change and the framing...
DEFF Research Database (Denmark)
Vind, Karl
1991-01-01
A simple mathematical result characterizing a subset of a product set is proved and used to obtain additive representations of preferences. The additivity consequences of independence assumptions are obtained for preferences which are not total or transitive. This means that most of the economic ...... theory based on additive preferences - expected utility, discounted utility - has been generalized to preferences which are not total or transitive. Other economic applications of the theorem are given...
Preliminary Theoretical Interpretation of the Tajmar Frame Dragging Effect Through the GEM Theory
International Nuclear Information System (INIS)
Brandenburg, John
2009-01-01
A preliminary theoretical explanation for the large amplitude frame dragging effect seen by Tajmar et al.(2007) is proposed. A simple theory of quantum photon fields mediating electrodynamics is derived based on concepts from QED. These are then expressed as quantum wave functions for rotating EM systems. Based on the GEM theory, it is proposed that gravitational frame dragging relies on similar photon wave functions. The constructive interference of the frame dragging fields with co-rotating EM photon fields coupled to Bose-Einstein components in matter at low temperatures results in a large frame dragging term due to a mixed gravity-EM term that is larger by a factor of approximately 10 20 than ordinary frame dragging.
Determinism, independence, and objectivity are incompatible.
Ionicioiu, Radu; Mann, Robert B; Terno, Daniel R
2015-02-13
Hidden-variable models aim to reproduce the results of quantum theory and to satisfy our classical intuition. Their refutation is usually based on deriving predictions that are different from those of quantum mechanics. Here instead we study the mutual compatibility of apparently reasonable classical assumptions. We analyze a version of the delayed-choice experiment which ostensibly combines determinism, independence of hidden variables on the conducted experiments, and wave-particle objectivity (the assertion that quantum systems are, at any moment, either particles or waves, but not both). These three ideas are incompatible with any theory, not only with quantum mechanics.
column frame for design of reinforced concrete sway frames
African Journals Online (AJOL)
adminstrator
design of slender reinforced concrete columns in sway frames according .... concrete,. Ac = gross cross-sectional area of the columns. Step 3: Effective Buckling Length Factors. The effective buckling length factors of columns in a sway frame shall be computed by .... shall have adequate resistance to failure in a sway mode ...
Power to the frame: bringing sociology back to frame analysis
Vliegenthart, R.; van Zoonen, L.
2011-01-01
This article critically reviews current frame and framing research in media and communication studies. It is first argued that most authors fail to distinguish between ‘frame’ and ‘framing’ and therewith produce a conceptual confusion and imprecision that is not conducive to the field. Second, it is
Value Framing: A Prelude to Software Problem Framing
Wieringa, Roelf J.; Gordijn, Jaap; van Eck, Pascal; Cox, K.; Hall, J.G.; Rapanotti, L.
2004-01-01
Software problem framing is a way to find specifications for software. Software problem frames can be used to structure the environment of a software system (the machine) and specify desired software properties in such a way that we can show that software with these properties will help achieve the
New characterizations of fusion frames (frames of subspaces)
Indian Academy of Sciences (India)
Theory (College Park, MD, 2003) Contemp. Math. 345, Amer. Math. Soc. (RI: Provi- dence) (2004) 87–113. [4] Casazza P G and Kutyniok G, Robustness of Fusion Frames under Erasures of sub- spaces and of Local Frame Vectors, Radon transforms, geometry, and wavelets (LA: New Orleans) (2006) Contemp. Math., Amer.
Applications of quantum information theory to quantum gravity
International Nuclear Information System (INIS)
Smolin, L.
2005-01-01
Full text: I describe work by and with Fotini Markopoulou and Olaf Dreyeron the application of quantum information theory to quantum gravity. A particular application to black hole physics is described, which treats the black hole horizon as an open system, in interaction with an environment, which are the degrees of freedom in the bulk spacetime. This allows us to elucidate which quantum states of a general horizon contribute to the entropy of a Schwarzchild black hole. This case serves as an example of how methods from quantum information theory may help to elucidate how the classical limit emerges from a background independent quantum theory of gravity. (author)
Body frames and frame singularities for three-atom systems
International Nuclear Information System (INIS)
Littlejohn, R.G.; Mitchell, K.A.; Aquilanti, V.; Cavalli, S.
1998-01-01
The subject of body frames and their singularities for three-particle systems is important not only for large-amplitude rovibrational coupling in molecular spectroscopy, but also for reactive scattering calculations. This paper presents a geometrical analysis of the meaning of body frame conventions and their singularities in three-particle systems. Special attention is devoted to the principal axis frame, a certain version of the Eckart frame, and the topological inevitability of frame singularities. The emphasis is on a geometrical picture, which is intended as a preliminary study for the more difficult case of four-particle systems, where one must work in higher-dimensional spaces. The analysis makes extensive use of kinematic rotations. copyright 1998 The American Physical Society
Riesz Frames and Approximation of the Frame Coefficients
DEFF Research Database (Denmark)
Christensen, Ole
1996-01-01
A frame is a familyof elements in a Hilbert space with the propertythat every element in the Hilbert space can be written as a (infinite)linear combination of the frame elements. Frame theory describes howone can choose the corresponding coefficients, which are calledframe coefficients. From...... the mathematical point of view this isgratifying, but for applications it is a problem that the calculationrequires inversion of an operator on the Hilbert space.The projection method is introduced in order to avoid this problem.The basic idea is to consider finite subfamiliesof the frame and the orthogonal...... projection onto its span. Forfin QTR H,P_nf has a representation as a linear combinationof f_i,i=1,2,..,n, and the corresponding coefficients can be calculatedusing finite dimensional methods. We find conditions implying that thosecoefficients converge to the correct frame coefficients as n goes...
Framing the frame: How task goals determine the likelihood and direction of framing effects
Todd McElroy; John J. Seta
2007-01-01
We examined how the goal of a decision task influences the perceived positive, negative valence of the alternatives and thereby the likelihood and direction of framing effects. In Study 1 we manipulated the goal to increase, decrease or maintain the commodity in question and found that when the goal of the task was to increase the commodity, a framing effect consistent with those typically observed in the literature was found. When the goal was to decrease, a framing effect opposite to the ty...
Video Encryption and Decryption on Quantum Computers
Yan, Fei; Iliyasu, Abdullah M.; Venegas-Andraca, Salvador E.; Yang, Huamin
2015-08-01
A method for video encryption and decryption on quantum computers is proposed based on color information transformations on each frame encoding the content of the encoding the content of the video. The proposed method provides a flexible operation to encrypt quantum video by means of the quantum measurement in order to enhance the security of the video. To validate the proposed approach, a tetris tile-matching puzzle game video is utilized in the experimental simulations. The results obtained suggest that the proposed method enhances the security and speed of quantum video encryption and decryption, both properties required for secure transmission and sharing of video content in quantum communication.
DEFF Research Database (Denmark)
Ringe, Wolf-Georg
2013-01-01
This paper re-evaluates the corporate governance concept of ‘board independence’ against the disappointing experiences during the 2007-08 financial crisis. Independent or outside directors had long been seen as an essential tool to improve the monitoring role of the board. Yet the crisis revealed...... that they did not prevent firms' excessive risk taking; further, these directors sometimes showed serious deficits in understanding the business they were supposed to control, and remained passive in addressing structural problems. A closer look reveals that under the surface of seemingly unanimous consensus...
[The framing effect: medical implications].
Mazzocco, Ketti; Cherubini, Paolo; Rumiati, Rino
2005-01-01
Over the last 20 years, many studies explored how the way information is presented modifies choices. This sort of effect, referred to as "framing effects", typically consists of the inversion of choices when presenting structurally identical decision problems in different ways. It is a common assumption that physicians are unaffected (or less affected) by the surface description of a decision problem, because they are formally trained in medical decision making. However, several studies showed that framing effects occur even in the medical field. The complexity and variability of these effects are remarkable, making it necessary to distinguish among different framing effects, depending on whether the effect is obtained by modifying adjectives (attribute framing), goals of a behavior (goal framing), or the probability of an outcome (risky choice framing). A further reason for the high variability of the framing effects seems to be the domain of the decision problem, with different effects occurring in prevention decisions, disease-detection decisions, and treatment decisions. The present work reviews the studies on framing effects, in order to summarize them and clarify their possible role in medical decision making.
FRAME CATAGORIZATION OF CONVERSATIONAL INTIMACY
Lyubov Kit
2017-01-01
The article deals with the notion of intimacy. The frame of intimacy is studied on the basis of the linguistic parameters, analysis of text extracts and universal knowledge about intimacy. Frame analysis helped to establish the catagorization of types and nominators of intimate speech genres, their construction in static and dynamic aspects.
Frame Catagorization of Conversational Intimacy
Lyubov Kit
2017-01-01
The article deals with the notion of intimacy. The frame of intimacy is studied on the basis of the linguistic parameters, analysis of text extracts and universal knowledge about intimacy. Frame analysis helped to establish the catagorization of types and nominators of intimate speech genres, their construction in static and dynamic aspects.
Quantum networks based on cavity QED
Energy Technology Data Exchange (ETDEWEB)
Ritter, Stephan; Bochmann, Joerg; Figueroa, Eden; Hahn, Carolin; Kalb, Norbert; Muecke, Martin; Neuzner, Andreas; Noelleke, Christian; Reiserer, Andreas; Uphoff, Manuel; Rempe, Gerhard [Max-Planck-Institut fuer Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching (Germany)
2014-07-01
Quantum repeaters require an efficient interface between stationary quantum memories and flying photons. Single atoms in optical cavities are ideally suited as universal quantum network nodes that are capable of sending, storing, retrieving, and even processing quantum information. We demonstrate this by presenting an elementary version of a quantum network based on two identical nodes in remote, independent laboratories. The reversible exchange of quantum information and the creation of remote entanglement are achieved by exchange of a single photon. Quantum teleportation is implemented using a time-resolved photonic Bell-state measurement. Quantum control over all degrees of freedom of the single atom also allows for the nondestructive detection of flying photons and the implementation of a quantum gate between the spin state of the atom and the polarization of a photon upon its reflection from the cavity. Our approach to quantum networking offers a clear perspective for scalability and provides the essential components for the realization of a quantum repeater.
Energy Technology Data Exchange (ETDEWEB)
Knill, E.; Laflamme, R.
1996-07-01
One main problem for the future of practial quantum computing is to stabilize the computation against unwanted interactions with the environment and imperfections in the applied operations. Existing proposals for quantum memories and quantum channels require gates with asymptotically zero error to store or transmit an input quantum state for arbitrarily long times or distances with fixed error. This report gives a method which has the property that to store or transmit a qubit with maximum error {epsilon} requires gates with errors at most {ital c}{epsilon} and storage or channel elements with error at most {epsilon}, independent of how long we wish to store the state or how far we wish to transmit it. The method relies on using concatenated quantum codes and hierarchically implemented recovery operations. The overhead of the method is polynomial in the time of storage or the distance of the transmission. Rigorous and heuristic lower bounds for the constant {ital c} are given.
Quantum walks, quantum gates, and quantum computers
International Nuclear Information System (INIS)
Hines, Andrew P.; Stamp, P. C. E.
2007-01-01
The physics of quantum walks on graphs is formulated in Hamiltonian language, both for simple quantum walks and for composite walks, where extra discrete degrees of freedom live at each node of the graph. It is shown how to map between quantum walk Hamiltonians and Hamiltonians for qubit systems and quantum circuits; this is done for both single-excitation and multiexcitation encodings. Specific examples of spin chains, as well as static and dynamic systems of qubits, are mapped to quantum walks, and walks on hyperlattices and hypercubes are mapped to various gate systems. We also show how to map a quantum circuit performing the quantum Fourier transform, the key element of Shor's algorithm, to a quantum walk system doing the same. The results herein are an essential preliminary to a Hamiltonian formulation of quantum walks in which coupling to a dynamic quantum environment is included
Pylkkänen, Paavo
2015-12-01
The theme of phenomenology and quantum physics is here tackled by examining some basic interpretational issues in quantum physics. One key issue in quantum theory from the very beginning has been whether it is possible to provide a quantum ontology of particles in motion in the same way as in classical physics, or whether we are restricted to stay within a more limited view of quantum systems, in terms of complementary but mutually exclusive phenomena. In phenomenological terms we could describe the situation by saying that according to the usual interpretation of quantum theory (especially Niels Bohr's), quantum phenomena require a kind of epoché (i.e. a suspension of assumptions about reality at the quantum level). However, there are other interpretations (especially David Bohm's) that seem to re-establish the possibility of a mind-independent ontology at the quantum level. We will show that even such ontological interpretations contain novel, non-classical features, which require them to give a special role to "phenomena" or "appearances", a role not encountered in classical physics. We will conclude that while ontological interpretations of quantum theory are possible, quantum theory implies the need of a certain kind of epoché even for this type of interpretations. While different from the epoché connected to phenomenological description, the "quantum epoché" nevertheless points to a potentially interesting parallel between phenomenology and quantum philosophy. Copyright © 2015. Published by Elsevier Ltd.
Frames and outer frames for Hilbert C^*-modules
Arambašić, Ljiljana; Bakić, Damir
2015-01-01
The goal of the present paper is to extend the theory of frames for countably generated Hilbert $C^*$-modules over arbitrary $C^*$-algebras. In investigating the non-unital case we introduce the concept of outer frame as a sequence in the multiplier module $M(X)$ that has the standard frame property when applied to elements of the ambient module $X$. Given a Hilbert $\\A$-module $X$, we prove that there is a bijective correspondence of the set of all adjointable surjections from the generalize...
Some analogies between quantum cloning and quantum deleting
International Nuclear Information System (INIS)
Qiu Daowen
2002-01-01
We further verify the impossibility of deleting an arbitrary unknown quantum state, and also show it is impossible to delete two nonorthogonal quantum states as a consequence of unitarity of quantum mechanics. A quantum approximate (deterministic) deleting machine and a probabilistic (exact) deleting machine are constructed. The estimation for the global fidelity characterizing the efficiency of the quantum approximate deleting is given. We then demonstrate that unknown nonorthogonal states chosen from a set with their multiple copies can evolve into a linear superposition of multiple deletions and failure branches by a unitary process if and only if the states are linearly independent. It is notable that the proof for necessity is somewhat different from Pati's [Phys. Rev. Lett. 83, 2849 (1999)]. Another deleting machine for the input states that are unnecessarily linearly independent is also presented. The bounds on the success probabilities of these deleting machines are derived. So we expound some preliminary analogies between quantum cloning and deleting
Le Gouët, Jean-Louis; Moiseev, Sergey
2012-06-01
Interaction of quantum radiation with multi-particle ensembles has sparked off intense research efforts during the past decade. Emblematic of this field is the quantum memory scheme, where a quantum state of light is mapped onto an ensemble of atoms and then recovered in its original shape. While opening new access to the basics of light-atom interaction, quantum memory also appears as a key element for information processing applications, such as linear optics quantum computation and long-distance quantum communication via quantum repeaters. Not surprisingly, it is far from trivial to practically recover a stored quantum state of light and, although impressive progress has already been accomplished, researchers are still struggling to reach this ambitious objective. This special issue provides an account of the state-of-the-art in a fast-moving research area that makes physicists, engineers and chemists work together at the forefront of their discipline, involving quantum fields and atoms in different media, magnetic resonance techniques and material science. Various strategies have been considered to store and retrieve quantum light. The explored designs belong to three main—while still overlapping—classes. In architectures derived from photon echo, information is mapped over the spectral components of inhomogeneously broadened absorption bands, such as those encountered in rare earth ion doped crystals and atomic gases in external gradient magnetic field. Protocols based on electromagnetic induced transparency also rely on resonant excitation and are ideally suited to the homogeneous absorption lines offered by laser cooled atomic clouds or ion Coulomb crystals. Finally off-resonance approaches are illustrated by Faraday and Raman processes. Coupling with an optical cavity may enhance the storage process, even for negligibly small atom number. Multiple scattering is also proposed as a way to enlarge the quantum interaction distance of light with matter. The
Framed School--Frame Factors, Frames and the Dynamics of Social Interaction in School
Persson, Anders
2015-01-01
This paper aims to show how the Goffman frame perspective can be used in an analysis of school and education and how it can be combined, in such analysis, with the frame factor perspective. The latter emphasizes factors that are determined outside the teaching process, while the former stresses how actors organize their experiences and define…
Arfi, Badredine
2007-02-01
Most game-theoretic studies of strategic interaction assume independent individual strategies as the basic unit of analysis. This paper explores the effects of non-independence on strategic interaction. Two types of non-independence effects are considered. First, the paper considers subjective non-independence at the level of the individual actor by looking at how choice ambivalence shapes the decision-making process. Specifically, how do alternative individual choices superpose with one another to “constructively/destructively” shape each other's role within an actor's decision-making process? This process is termed as quantum superposition of alternative choices. Second, the paper considers how inter-subjective non-independence across actors engenders collective strategies among two or more interacting actors. This is termed as quantum entanglement of strategies. Taking into account both types of non-independence effect makes possible the emergence of a new collective equilibrium, without assuming signaling, prior “contract” agreement or third-party moderation, or even “cheap talk”. I apply these ideas to analyze the equilibrium possibilities of a situation wherein N actors play a quantum social game of cooperation. I consider different configurations of large- N quantum entanglement using the approach of density operator. I specifically consider the following configurations: star-shaped, nearest-neighbors, and full entanglement.
Towards quantum gravity via quantum field theory. Problems and perspectives
Energy Technology Data Exchange (ETDEWEB)
Fredenhagen, Klaus [II. Institut fuer Theoretische Physik, Universitaet Hamburg (Germany)
2016-07-01
General Relativity is a classical field theory; the standard methods for constructing a corresponding quantum field theory, however, meet severe difficulties, in particular perturbative non-renormalizability and the problem of background independence. Nevertheless, modern approaches to quantum field theory have significantly lowered these obstacles. On the side of non-renormalizability, this is the concept of effective theories, together with indications for better non-perturbative features of the renormalization group flow. On the side of background independence the main progress comes from an improved understanding of quantum field theories on generic curved spacetimes. Combining these informations, a promising approach to quantum gravity is an expansion around a classical solution which then is a quantum field theory on a given background, augmented by an identity which expresses independence against infinitesimal shifts of the background. The arising theory is expected to describe small corrections to classical general relativity. Inflationary cosmology is expected to arise as a lowest order approximation.
serialising languages: satellite-framed, verb-framed or neither
African Journals Online (AJOL)
George Saad
Figure 2: Verb-framed construction type (Slobin 2000: 109). 2 ... 2 An anonymous reviewer asks why we have replaced Talmy's conflation term “Ground” with ..... an S-language may predispose speakers to pay more linguistic attention to.
Chang, Mou-Hsiung
2015-01-01
The classical probability theory initiated by Kolmogorov and its quantum counterpart, pioneered by von Neumann, were created at about the same time in the 1930s, but development of the quantum theory has trailed far behind. Although highly appealing, the quantum theory has a steep learning curve, requiring tools from both probability and analysis and a facility for combining the two viewpoints. This book is a systematic, self-contained account of the core of quantum probability and quantum stochastic processes for graduate students and researchers. The only assumed background is knowledge of the basic theory of Hilbert spaces, bounded linear operators, and classical Markov processes. From there, the book introduces additional tools from analysis, and then builds the quantum probability framework needed to support applications to quantum control and quantum information and communication. These include quantum noise, quantum stochastic calculus, stochastic quantum differential equations, quantum Markov semigrou...
Modern canonical quantum general relativity
Thiemann, Thomas
2007-01-01
This is an introduction to the by now fifteen years old research field of canonical quantum general relativity, sometimes called "loop quantum gravity". The term "modern" in the title refers to the fact that the quantum theory is based on formulating classical general relativity as a theory of connections rather than metrics as compared to in original version due to Arnowitt, Deser and Misner. Canonical quantum general relativity is an attempt to define a mathematically rigorous, non-perturbative, background independent theory of Lorentzian quantum gravity in four spacetime dimensions in the continuum. The approach is minimal in that one simply analyzes the logical consequences of combining the principles of general relativity with the principles of quantum mechanics. The requirement to preserve background independence has lead to new, fascinating mathematical structures which one does not see in perturbative approaches, e.g. a fundamental discreteness of spacetime seems to be a prediction of the theory provi...
Noncommutative mathematics for quantum systems
Franz, Uwe
2016-01-01
Noncommutative mathematics is a significant new trend of mathematics. Initially motivated by the development of quantum physics, the idea of 'making theory noncommutative' has been extended to many areas of pure and applied mathematics. This book is divided into two parts. The first part provides an introduction to quantum probability, focusing on the notion of independence in quantum probability and on the theory of quantum stochastic processes with independent and stationary increments. The second part provides an introduction to quantum dynamical systems, discussing analogies with fundamental problems studied in classical dynamics. The desire to build an extension of the classical theory provides new, original ways to understand well-known 'commutative' results. On the other hand the richness of the quantum mathematical world presents completely novel phenomena, never encountered in the classical setting. This book will be useful to students and researchers in noncommutative probability, mathematical physi...
Serialising languages: Satellite-framed, verb-framed or neither ...
African Journals Online (AJOL)
The diversity in the coding of the core schema of motion, i.e., Path, has led to a traditional typology of languages into verb-framed and satellite-framed languages. In the former Path is encoded in verbs and in the latter it is encoded in non-verb elements that function as sisters to co-event expressing verbs such as manner ...
Scarani, Valerio
1998-01-01
The aim of this thesis was to explain what quantum computing is. The information for the thesis was gathered from books, scientific publications, and news articles. The analysis of the information revealed that quantum computing can be broken down to three areas: theories behind quantum computing explaining the structure of a quantum computer, known quantum algorithms, and the actual physical realizations of a quantum computer. The thesis reveals that moving from classical memor...
Wu, Lian-Ao; Lidar, Daniel A.
2005-01-01
When quantum communication networks proliferate they will likely be subject to a new type of attack: by hackers, virus makers, and other malicious intruders. Here we introduce the concept of "quantum malware" to describe such human-made intrusions. We offer a simple solution for storage of quantum information in a manner which protects quantum networks from quantum malware. This solution involves swapping the quantum information at random times between the network and isolated, distributed an...
Quantumness beyond quantum mechanics
International Nuclear Information System (INIS)
Sanz, Ángel S
2012-01-01
Bohmian mechanics allows us to understand quantum systems in the light of other quantum traits than the well-known ones (coherence, diffraction, interference, tunnelling, discreteness, entanglement, etc.). Here the discussion focusses precisely on two of these interesting aspects, which arise when quantum mechanics is thought within this theoretical framework: the non-crossing property, which allows for distinguishability without erasing interference patterns, and the possibility to define quantum probability tubes, along which the probability remains constant all the way. Furthermore, taking into account this hydrodynamic-like description as a link, it is also shown how this knowledge (concepts and ideas) can be straightforwardly transferred to other fields of physics (for example, the transmission of light along waveguides).
Equivalence principle and quantum mechanics: quantum simulation with entangled photons.
Longhi, S
2018-01-15
Einstein's equivalence principle (EP) states the complete physical equivalence of a gravitational field and corresponding inertial field in an accelerated reference frame. However, to what extent the EP remains valid in non-relativistic quantum mechanics is a controversial issue. To avoid violation of the EP, Bargmann's superselection rule forbids a coherent superposition of states with different masses. Here we suggest a quantum simulation of non-relativistic Schrödinger particle dynamics in non-inertial reference frames, which is based on the propagation of polarization-entangled photon pairs in curved and birefringent optical waveguides and Hong-Ou-Mandel quantum interference measurement. The photonic simulator can emulate superposition of mass states, which would lead to violation of the EP.
Directory of Open Access Journals (Sweden)
Rovelli Carlo
1998-01-01
Full Text Available The problem of finding the quantum theory of the gravitational field, and thus understanding what is quantum spacetime, is still open. One of the most active of the current approaches is loop quantum gravity. Loop quantum gravity is a mathematically well-defined, non-perturbative and background independent quantization of general relativity, with its conventional matter couplings. Research in loop quantum gravity today forms a vast area, ranging from mathematical foundations to physical applications. Among the most significant results obtained are: (i The computation of the physical spectra of geometrical quantities such as area and volume, which yields quantitative predictions on Planck-scale physics. (ii A derivation of the Bekenstein-Hawking black hole entropy formula. (iii An intriguing physical picture of the microstructure of quantum physical space, characterized by a polymer-like Planck scale discreteness. This discreteness emerges naturally from the quantum theory and provides a mathematically well-defined realization of Wheeler's intuition of a spacetime ``foam''. Long standing open problems within the approach (lack of a scalar product, over-completeness of the loop basis, implementation of reality conditions have been fully solved. The weak part of the approach is the treatment of the dynamics: at present there exist several proposals, which are intensely debated. Here, I provide a general overview of ideas, techniques, results and open problems of this candidate theory of quantum gravity, and a guide to the relevant literature.
Framing Effect in the Trolley Problem and Footbridge Dilemma.
Cao, Fei; Zhang, Jiaxi; Song, Lei; Wang, Shoupeng; Miao, Danmin; Peng, Jiaxi
2017-02-01
The present study investigated the effect of dilemma type, framing, and number of saved lives on moral decision making. A total of 591 undergraduates, with a mean age of 20.56 (SD = 1.37) were randomly assigned to 12 groups on the basis of a grid of two dilemma types (the trolley problem or the footbridge dilemma) by three frames (positive, neutral, or negative frame) by two different numbers of workers (5 or 15 people). The main effects of dilemma type, frame, and number of saved workers were all significant. The interaction of dilemma type and number of saved workers and the interaction of the three independent factors were significant. Results indicated that moral judgment is affected by framing. Specifically, people were more inclined to utilitarianism in the positive or neutral frame and more inclined to intuitionism in the negative frame. Furthermore, this effect can be moderated by dilemma type and number of saved lives. Implications of our results are discussed.
Nonlinear Dynamics In Quantum Physics -- Quantum Chaos and Quantum Instantons
Kröger, H.
2003-01-01
We discuss the recently proposed quantum action - its interpretation, its motivation, its mathematical properties and its use in physics: quantum mechanical tunneling, quantum instantons and quantum chaos.
Frames and counter-frames giving meaning to dementia: a framing analysis of media content.
Van Gorp, Baldwin; Vercruysse, Tom
2012-04-01
Media tend to reinforce the stigmatization of dementia as one of the most dreaded diseases in western society, which may have repercussions on the quality of life of those with the illness. The persons with dementia, but also those around them become imbued with the idea that life comes to an end as soon as the diagnosis is pronounced. The aim of this paper is to understand the dominant images related to dementia by means of an inductive framing analysis. The sample is composed of newspaper articles from six Belgian newspapers (2008-2010) and a convenience sample of popular images of the condition in movies, documentaries, literature and health care communications. The results demonstrate that the most dominant frame postulates that a human being is composed of two distinct parts: a material body and an immaterial mind. If this frame is used, the person with dementia ends up with no identity, which is in opposition to the Western ideals of personal self-fulfilment and individualism. For each dominant frame an alternative counter-frame is defined. It is concluded that the relative absence of counter-frames confirms the negative image of dementia. The inventory might be a help for caregivers and other professionals who want to evaluate their communication strategy. It is discussed that a more resolute use of counter-frames in communication about dementia might mitigate the stigma that surrounds dementia. Copyright © 2012 Elsevier Ltd. All rights reserved.
Directory of Open Access Journals (Sweden)
Valerie Jean O’Keeffe
2015-06-01
Full Text Available Current patient safety policy focuses nursing on patient care goals, often overriding nurses’ safety. Without understanding how nurses construct work health and safety (WHS, patient and nurse safety cannot be reconciled. Using ethnography, we examine social contexts of safety, studying 72 nurses across five Australian hospitals making decisions during patient encounters. In enacting safe practice, nurses used “frames” built from their contextual experiences to guide their behavior. Frames are produced by nurses, and they structure how nurses make sense of their work. Using thematic analysis, we identify four frames that inform nurses’ decisions about WHS: (a communicating builds knowledge, (b experiencing situations guides decisions, (c adapting procedures streamlines work, and (d team working promotes safe working. Nurses’ frames question current policy and practice by challenging how nurses’ safety is positioned relative to patient safety. Recognizing these frames can assist the design and implementation of effective WHS management.
Rovelli, Carlo
2008-01-01
The problem of describing the quantum behavior of gravity, and thus understanding quantum spacetime , is still open. Loop quantum gravity is a well-developed approach to this problem. It is a mathematically well-defined background-independent quantization of general relativity, with its conventional matter couplings. Today research in loop quantum gravity forms a vast area, ranging from mathematical foundations to physical applications. Among the most significant results obtained so far are: (i) The computation of the spectra of geometrical quantities such as area and volume, which yield tentative quantitative predictions for Planck-scale physics. (ii) A physical picture of the microstructure of quantum spacetime, characterized by Planck-scale discreteness. Discreteness emerges as a standard quantum effect from the discrete spectra, and provides a mathematical realization of Wheeler's "spacetime foam" intuition. (iii) Control of spacetime singularities, such as those in the interior of black holes and the cosmological one. This, in particular, has opened up the possibility of a theoretical investigation into the very early universe and the spacetime regions beyond the Big Bang. (iv) A derivation of the Bekenstein-Hawking black-hole entropy. (v) Low-energy calculations, yielding n -point functions well defined in a background-independent context. The theory is at the roots of, or strictly related to, a number of formalisms that have been developed for describing background-independent quantum field theory, such as spin foams, group field theory, causal spin networks, and others. I give here a general overview of ideas, techniques, results and open problems of this candidate theory of quantum gravity, and a guide to the relevant literature.
Directory of Open Access Journals (Sweden)
Rovelli Carlo
2008-07-01
Full Text Available The problem of describing the quantum behavior of gravity, and thus understanding quantum spacetime, is still open. Loop quantum gravity is a well-developed approach to this problem. It is a mathematically well-defined background-independent quantization of general relativity, with its conventional matter couplings. Today research in loop quantum gravity forms a vast area, ranging from mathematical foundations to physical applications. Among the most significant results obtained so far are: (i The computation of the spectra of geometrical quantities such as area and volume, which yield tentative quantitative predictions for Planck-scale physics. (ii A physical picture of the microstructure of quantum spacetime, characterized by Planck-scale discreteness. Discreteness emerges as a standard quantum effect from the discrete spectra, and provides a mathematical realization of Wheeler’s “spacetime foam” intuition. (iii Control of spacetime singularities, such as those in the interior of black holes and the cosmological one. This, in particular, has opened up the possibility of a theoretical investigation into the very early universe and the spacetime regions beyond the Big Bang. (iv A derivation of the Bekenstein–Hawking black-hole entropy. (v Low-energy calculations, yielding n-point functions well defined in a background-independent context. The theory is at the roots of, or strictly related to, a number of formalisms that have been developed for describing background-independent quantum field theory, such as spin foams, group field theory, causal spin networks, and others. I give here a general overview of ideas, techniques, results and open problems of this candidate theory of quantum gravity, and a guide to the relevant literature.
Decoherence-full subsystems and the cryptographic power of a private shared reference frame
International Nuclear Information System (INIS)
Bartlett, Stephen D.; Rudolph, Terry; Spekkens, Robert W.
2004-01-01
We show that private shared reference frames can be used to perform private quantum and private classical communication over a public quantum channel. Such frames constitute a type of private shared correlation, distinct from private classical keys or shared entanglement, useful for cryptography. We present optimally efficient schemes for private quantum and classical communication given a finite number of qubits transmitted over an insecure channel and given a private shared Cartesian frame and/or a private shared reference ordering of the qubits. We show that in this context, it is useful to introduce the concept of a decoherence-full subsystem, wherein every state is mapped to the completely mixed state under the action of the decoherence
Gabor Frames in ℓ2(Z) and Linear Dependence
DEFF Research Database (Denmark)
Christensen, Ole; Hasannasab, Marzieh
2017-01-01
We prove that an overcomplete Gabor frame in (Formula presented.) generated by a finitely supported sequence is always linearly dependent. This is a particular case of a general result about linear dependence versus independence for Gabor systems in (Formula presented.) with modulation parameter ...
Hemispheric Correlates of the Rod-And-Frame Test.
Berlin, Donna F.; Languis, Marlin L.
1981-01-01
Right-handed sixth graders were administered the WISC Block Design and verbal and nonverbal versions of the Rod-and-Frame Test (RFT), measuring field dependence/independence. Results seemed to reflect a right hemisphere processing for the nonverbal RFT and a possible sex bias against girls in its traditional verbal administration. (Author/SJL)
Detected-jump-error-correcting quantum codes, quantum error designs, and quantum computation
International Nuclear Information System (INIS)
Alber, G.; Mussinger, M.; Beth, Th.; Charnes, Ch.; Delgado, A.; Grassl, M.
2003-01-01
The recently introduced detected-jump-correcting quantum codes are capable of stabilizing qubit systems against spontaneous decay processes arising from couplings to statistically independent reservoirs. These embedded quantum codes exploit classical information about which qubit has emitted spontaneously and correspond to an active error-correcting code embedded in a passive error-correcting code. The construction of a family of one-detected-jump-error-correcting quantum codes is shown and the optimal redundancy, encoding, and recovery as well as general properties of detected-jump-error-correcting quantum codes are discussed. By the use of design theory, multiple-jump-error-correcting quantum codes can be constructed. The performance of one-jump-error-correcting quantum codes under nonideal conditions is studied numerically by simulating a quantum memory and Grover's algorithm
International Nuclear Information System (INIS)
Ghatak, A.K.; Lokanathan, S.
1975-01-01
This textbook on quantum mechanics is intended for students at the graduate and post-graduate level. A balanced account of theory and applications is presented. Emphasis is laid on making results plausible and methods to be followed in solving problems. The various chapters in the book are devoted to the following: (1) Wave particle duality and uncertainty principle (2) Wave packets and time-dependent Schroedinger equation (3) Simple solutions of Schroedinger equation (4) Vector spaces and linear operators : Dirac notation (5) Angular momentum and spin (6) Addition of angular momenta (7) Time independent perturbation theory (8) The variational method (9) The WKB approximation (10) Elementary theory of scattering (11) Time-dependent perturbation theory (12) Motion in a magnetic field (13) Interaction of radiation with matter and (14) Relativistic theory. (A.K.)
Adding control to arbitrary unknown quantum operations
Zhou, Xiao-Qi; Ralph, Timothy C.; Kalasuwan, Pruet; Zhang, Mian; Peruzzo, Alberto; Lanyon, Benjamin P.; O'Brien, Jeremy L.
2011-01-01
Although quantum computers promise significant advantages, the complexity of quantum algorithms remains a major technological obstacle. We have developed and demonstrated an architecture-independent technique that simplifies adding control qubits to arbitrary quantum operations—a requirement in many quantum algorithms, simulations and metrology. The technique, which is independent of how the operation is done, does not require knowledge of what the operation is, and largely separates the problems of how to implement a quantum operation in the laboratory and how to add a control. Here, we demonstrate an entanglement-based version in a photonic system, realizing a range of different two-qubit gates with high fidelity. PMID:21811242
International Nuclear Information System (INIS)
Anon.
1990-01-01
The book is on quantum mechanics. The emphasis is on the basic concepts and the methodology. The chapters include: Breakdown of classical concepts; Quantum mechanical concepts; Basic postulates of quantum mechanics; solution of problems in quantum mechanics; Simple harmonic oscillator; and Angular Momentum
International Nuclear Information System (INIS)
Buechler, Hans Peter; Calcarco, Tommaso; Dressel, Martin
2008-01-01
The following topics are dealt with: Artificial atoms and molecules, tailored from solids, fractional flux quanta, molecular magnets, controlled interaction in quantum gases, the theory of quantum correlations in mott matter, cold gases, and mesoscopic systems, Bose-Einstein condensates on the chip, on the route to the quantum computer, a quantum computer in diamond. (HSI)
International Nuclear Information System (INIS)
Reynaud, S.; Giacobino, S.; Zinn-Justin, J.
1997-01-01
This course is dedicated to present in a pedagogical manner the recent developments in peculiar fields concerned by quantum fluctuations: quantum noise in optics, light propagation through dielectric media, sub-Poissonian light generated by lasers and masers, quantum non-demolition measurements, quantum electrodynamics applied to cavities and electrical circuits involving superconducting tunnel junctions. (A.C.)
Reynolds Stress Closure for Inertial Frames and Rotating Frames
Petty, Charles; Benard, Andre
2017-11-01
In a rotating frame-of-reference, the Coriolis acceleration and the mean vorticity field have a profound impact on the redistribution of kinetic energy among the three components of the fluctuating velocity. Consequently, the normalized Reynolds (NR) stress is not objective. Furthermore, because the Reynolds stress is defined as an ensemble average of a product of fluctuating velocity vector fields, its eigenvalues must be non-negative for all turbulent flows. These fundamental properties (realizability and non-objectivity) of the NR-stress cannot be compromised in computational fluid dynamic (CFD) simulations of turbulent flows in either inertial frames or in rotating frames. The recently developed universal realizable anisotropic prestress (URAPS) closure for the NR-stress depends explicitly on the local mean velocity gradient and the Coriolis operator. The URAPS-closure is a significant paradigm shift from turbulent closure models that assume that dyadic-valued operators associated with turbulent fluctuations are objective.
Lanzagorta, Marco
2011-01-01
This book offers a concise review of quantum radar theory. Our approach is pedagogical, making emphasis on the physics behind the operation of a hypothetical quantum radar. We concentrate our discussion on the two major models proposed to date: interferometric quantum radar and quantum illumination. In addition, this book offers some new results, including an analytical study of quantum interferometry in the X-band radar region with a variety of atmospheric conditions, a derivation of a quantum radar equation, and a discussion of quantum radar jamming.This book assumes the reader is familiar w
Quantum discord as a resource for quantum cryptography.
Pirandola, Stefano
2014-11-07
Quantum discord is the minimal bipartite resource which is needed for a secure quantum key distribution, being a cryptographic primitive equivalent to non-orthogonality. Its role becomes crucial in device-dependent quantum cryptography, where the presence of preparation and detection noise (inaccessible to all parties) may be so strong to prevent the distribution and distillation of entanglement. The necessity of entanglement is re-affirmed in the stronger scenario of device-independent quantum cryptography, where all sources of noise are ascribed to the eavesdropper.
Semihierarchical quantum repeaters based on moderate lifetime quantum memories
Liu, Xiao; Zhou, Zong-Quan; Hua, Yi-Lin; Li, Chuan-Feng; Guo, Guang-Can
2017-01-01
The construction of large-scale quantum networks relies on the development of practical quantum repeaters. Many approaches have been proposed with the goal of outperforming the direct transmission of photons, but most of them are inefficient or difficult to implement with current technology. Here, we present a protocol that uses a semihierarchical structure to improve the entanglement distribution rate while reducing the requirement of memory time to a range of tens of milliseconds. This protocol can be implemented with a fixed distance of elementary links and fixed requirements on quantum memories, which are independent of the total distance. This configuration is especially suitable for scalable applications in large-scale quantum networks.
International Nuclear Information System (INIS)
Kilin, Sergei Ya
1999-01-01
A new research direction known as quantum information is a multidisciplinary subject which involves quantum mechanics, optics, information theory, programming, discrete mathematics, laser physics and spectroscopy, and depends heavily on contributions from such areas as quantum computing, quantum teleportation and quantum cryptography, decoherence studies, and single-molecule and impurity spectroscopy. Some new results achieved in this rapidly growing field are discussed. (reviews of topical problems)
Energy Technology Data Exchange (ETDEWEB)
Kilin, Sergei Ya [B.I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, Minsk (Belarus)
1999-05-31
A new research direction known as quantum information is a multidisciplinary subject which involves quantum mechanics, optics, information theory, programming, discrete mathematics, laser physics and spectroscopy, and depends heavily on contributions from such areas as quantum computing, quantum teleportation and quantum cryptography, decoherence studies, and single-molecule and impurity spectroscopy. Some new results achieved in this rapidly growing field are discussed. (reviews of topical problems)
International Nuclear Information System (INIS)
Stapp, H.P.
1988-12-01
Quantum ontologies are conceptions of the constitution of the universe that are compatible with quantum theory. The ontological orientation is contrasted to the pragmatic orientation of science, and reasons are given for considering quantum ontologies both within science, and in broader contexts. The principal quantum ontologies are described and evaluated. Invited paper at conference: Bell's Theorem, Quantum Theory, and Conceptions of the Universe, George Mason University, October 20-21, 1988. 16 refs
Experimental Measurement-Device-Independent Entanglement Detection
Nawareg, Mohamed; Muhammad, Sadiq; Amselem, Elias; Bourennane, Mohamed
2015-02-01
Entanglement is one of the most puzzling features of quantum theory and of great importance for the new field of quantum information. The determination whether a given state is entangled or not is one of the most challenging open problems of the field. Here we report on the experimental demonstration of measurement-device-independent (MDI) entanglement detection using witness method for general two qubits photon polarization systems. In the MDI settings, there is no requirement to assume perfect implementations or neither to trust the measurement devices. This experimental demonstration can be generalized for the investigation of properties of quantum systems and for the realization of cryptography and communication protocols.
No drama quantum electrodynamics?
International Nuclear Information System (INIS)
Akhmeteli, Andrey
2013-01-01
This article builds on recent work (Akhmeteli in Int. J. Quantum Inf. 9(Supp01):17, 2011; J. Math. Phys. 52:082303, 2011), providing a theory that is based on spinor electrodynamics, is described by a system of partial differential equations in 3+1 dimensions, but reproduces unitary evolution of a quantum field theory in the Fock space. To this end, after introduction of a complex four-potential of electromagnetic field, which generates the same electromagnetic fields as the initial real four-potential, the spinor field is algebraically eliminated from the equations of spinor electrodynamics. It is proven that the resulting equations for electromagnetic field describe independent evolution of the latter and can be embedded into a quantum field theory using a generalized Carleman linearization procedure. The theory provides a simple and at least reasonably realistic model, valuable for interpretation of quantum theory. The issues related to the Bell theorem are discussed. (orig.)
Foundations of quantum gravity
Lindesay, James
2013-01-01
Exploring how the subtleties of quantum coherence can be consistently incorporated into Einstein’s theory of gravitation, this book is ideal for researchers interested in the foundations of relativity and quantum physics. The book examines those properties of coherent gravitating systems that are most closely connected to experimental observations. Examples of consistent co-gravitating quantum systems whose overall effects upon the geometry are independent of the coherence state of each constituent are provided, and the properties of the trapping regions of non-singular black objects, black holes, and a dynamic de Sitter cosmology are discussed analytically, numerically, and diagrammatically. The extensive use of diagrams to summarise the results of the mathematics enables readers to bypass the need for a detailed understanding of the steps involved. Assuming some knowledge of quantum physics and relativity, the book provides textboxes featuring supplementary information for readers particularly interested ...
International Nuclear Information System (INIS)
Hanson, Andrew J; Sabry, Amr; Ortiz, Gerardo; Tai, Yu-Tsung
2014-01-01
We explore finite-field frameworks for quantum theory and quantum computation. The simplest theory, defined over unrestricted finite fields, is unnaturally strong. A second framework employs only finite fields with no solution to x 2 + 1 = 0, and thus permits an elegant complex representation of the extended field by adjoining i=√(−1). Quantum theories over these fields recover much of the structure of conventional quantum theory except for the condition that vanishing inner products arise only from null states; unnaturally strong computational power may still occur. Finally, we are led to consider one more framework, with further restrictions on the finite fields, that recovers a local transitive order and a locally-consistent notion of inner product with a new notion of cardinal probability. In this framework, conventional quantum mechanics and quantum computation emerge locally (though not globally) as the size of the underlying field increases. Interestingly, the framework allows one to choose separate finite fields for system description and for measurement: the size of the first field quantifies the resources needed to describe the system and the size of the second quantifies the resources used by the observer. This resource-based perspective potentially provides insights into quantitative measures for actual computational power, the complexity of quantum system definition and evolution, and the independent question of the cost of the measurement process. (paper)
Quantum probabilistic logic programming
Balu, Radhakrishnan
2015-05-01
We describe a quantum mechanics based logic programming language that supports Horn clauses, random variables, and covariance matrices to express and solve problems in probabilistic logic. The Horn clauses of the language wrap random variables, including infinite valued, to express probability distributions and statistical correlations, a powerful feature to capture relationship between distributions that are not independent. The expressive power of the language is based on a mechanism to implement statistical ensembles and to solve the underlying SAT instances using quantum mechanical machinery. We exploit the fact that classical random variables have quantum decompositions to build the Horn clauses. We establish the semantics of the language in a rigorous fashion by considering an existing probabilistic logic language called PRISM with classical probability measures defined on the Herbrand base and extending it to the quantum context. In the classical case H-interpretations form the sample space and probability measures defined on them lead to consistent definition of probabilities for well formed formulae. In the quantum counterpart, we define probability amplitudes on Hinterpretations facilitating the model generations and verifications via quantum mechanical superpositions and entanglements. We cast the well formed formulae of the language as quantum mechanical observables thus providing an elegant interpretation for their probabilities. We discuss several examples to combine statistical ensembles and predicates of first order logic to reason with situations involving uncertainty.
Quantum Computer Games: Quantum Minesweeper
Gordon, Michal; Gordon, Goren
2010-01-01
The computer game of quantum minesweeper is introduced as a quantum extension of the well-known classical minesweeper. Its main objective is to teach the unique concepts of quantum mechanics in a fun way. Quantum minesweeper demonstrates the effects of superposition, entanglement and their non-local characteristics. While in the classical…
DEFF Research Database (Denmark)
Christensen, Ole; Lindner, Alexander M
2001-01-01
We give lower frame bounds for finite subfamilies of a frame of exponentials {e(i lambdak(.))}k is an element ofZ in L-2(-pi,pi). We also present a method for approximation of the inverse frame operator corresponding to {e(i lambdak(.))}k is an element ofZ, where knowledge of the frame bounds for...
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)
Message Framing and Physical Activity Promotion in Colorectal Cancer Survivors.
Hirschey, Rachel; Lipkus, Isaac; Jones, Lee; Mantyh, Christopher; Sloane, Richard; Demark-Wahnefried, Wendy
2016-11-01
To test effects of gain-framed versus loss-framed mailed brochures on increasing physical activity (PA) among colorectal cancer (CRC) survivors. . Randomized trial with repeated measures at baseline, 1 month, and 12 months postintervention. . Mail recruitment from tumor registries. . 148 inactive CRC survivors who had completed primary therapy. . PA and constructs from the Theory of Planned Behavior (TPB) were assessed at baseline, 1 month, and 12 months. Participants were randomized to receive pamphlets describing PA benefits (gain framed) or disadvantages of not being physically active (loss framed). Baseline characteristics were compared using descriptive statistics. Repeated measures linear models were used to test PA changes. . Minutes of PA and TPB constructs. . Significant PA increases were observed in both study arms. Results did not differ by message frame. At one month, about 25% of previously inactive participants increased activity to national recommendations. Those who increased PA compared to those who did not had higher baseline scores on subjective norms, perceived behavioral control, and PA intentions. . Independent of message framing, mailed brochures are highly effective in producing within-subject short- and long-term increases in PA. . CRC survivors may increase short- and long-term levels of PA by receiving inexpensive print brochures.
Another frame, another game? : Explaining framing effects in economic games
Gerlach, Philipp; Jaeger, B.; Hopfensitz, A.; Lori, E.
2016-01-01
Small changes in the framing of games (i.e., the way in which the game situation is described to participants) can have large effects on players' choices. For example, referring to a prisoner's dilemma game as the "Community Game" as opposed to the "Wall Street Game" can double the cooperation rate
Directory of Open Access Journals (Sweden)
Dharmanand Baboolal
2017-01-01
Full Text Available We discuss the congruences $theta$ that are connected as elements of the (totally disconnected congruence frame $CF L$, and show that they are in a one-to-one correspondence with the completely prime elements of $L$, giving an explicit formula. Then we investigate those frames $L$ with enough connected congruences to cover the whole of $CF L$. They are, among others, shown to be $T_D$-spatial; characteristics for some special cases (Boolean, linear, scattered and Noetherian are presented.
Geometric phase for a neutral particle in rotating frames in a cosmic string spacetime
International Nuclear Information System (INIS)
Bakke, Knut; Furtado, Claudio
2009-01-01
We study of the appearance of geometric quantum phases in the dynamics of a neutral particle that possess a permanent magnetic dipole moment in rotating frames in a cosmic string spacetime. The relativistic dynamics of spin-1/2 particle in this frame is investigated and we obtain several contributions to relativistic geometric phase due rotation and topology of spacetime. We also study the geometric phase in the nonrelativistic limit. We obtain effects analogous to the Sagnac effect and Mashhoon effect in a rotating frame in the background of a cosmic string.
Conserved quantities in background independent theories
Energy Technology Data Exchange (ETDEWEB)
Markopoulou, Fotini [Perimeter Institute for Theoretical Physics, 35 King Street North, Waterloo, Ontario N2J 2W9 (Canada); Department of Physics, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)
2007-05-15
We discuss the difficulties that background independent theories based on quantum geometry encounter in deriving general relativity as the low energy limit. We follow a geometrogenesis scenario of a phase transition from a pre-geometric theory to a geometric phase which suggests that a first step towards the low energy limit is searching for the effective collective excitations that will characterize it. Using the correspondence between the pre-geometric background independent theory and a quantum information processor, we are able to use the method of noiseless subsystems to extract such coherent collective excitations. We illustrate this in the case of locally evolving graphs.
Sparsity and spectral properties of dual frames
DEFF Research Database (Denmark)
Krahmer, Felix; Kutyniok, Gitta; Lemvig, Jakob
2013-01-01
We study sparsity and spectral properties of dual frames of a given finite frame. We show that any finite frame has a dual with no more than $n^2$ non-vanishing entries, where $n$ denotes the ambient dimension, and that for most frames no sparser dual is possible. Moreover, we derive an expressio...
Some equalities and inequalities for fusion frames
Guo, Qianping; Leng, Jinsong; Li, Houbiao
2016-01-01
Fusion frames have some properties similar to those of frames in Hilbert spaces, but not all of their properties are similar. Some authors have established some equalities and inequalities for conventional frames. In this paper, we give some equalities and inequalities for fusion frames. Our results generalize and improve the remarkable results which have been obtained by Balan, Casazza and G?vruta etc.
2010-10-01
... 49 Transportation 5 2010-10-01 2010-10-01 false Frames. 393.201 Section 393.201 Transportation... SAFE OPERATION Frames, Cab and Body Components, Wheels, Steering, and Suspension Systems § 393.201 Frames. (a) The frame or chassis of each commercial motor vehicle shall not be cracked, loose, sagging or...
Key Frame Extraction in the Summary Space.
Li, Xuelong; Zhao, Bin; Lu, Xiaoqiang; Xuelong Li; Bin Zhao; Xiaoqiang Lu; Lu, Xiaoqiang; Li, Xuelong; Zhao, Bin
2018-06-01
Key frame extraction is an efficient way to create the video summary which helps users obtain a quick comprehension of the video content. Generally, the key frames should be representative of the video content, meanwhile, diverse to reduce the redundancy. Based on the assumption that the video data are near a subspace of a high-dimensional space, a new approach, named as key frame extraction in the summary space, is proposed for key frame extraction in this paper. The proposed approach aims to find the representative frames of the video and filter out similar frames from the representative frame set. First of all, the video data are mapped to a high-dimensional space, named as summary space. Then, a new representation is learned for each frame by analyzing the intrinsic structure of the summary space. Specifically, the learned representation can reflect the representativeness of the frame, and is utilized to select representative frames. Next, the perceptual hash algorithm is employed to measure the similarity of representative frames. As a result, the key frame set is obtained after filtering out similar frames from the representative frame set. Finally, the video summary is constructed by assigning the key frames in temporal order. Additionally, the ground truth, created by filtering out similar frames from human-created summaries, is utilized to evaluate the quality of the video summary. Compared with several traditional approaches, the experimental results on 80 videos from two datasets indicate the superior performance of our approach.
Quark imaging in the proton via quantum phase-space distributions
International Nuclear Information System (INIS)
Belitsky, A.V.; Ji Xiangdong; Yuan Feng
2004-01-01
We develop the concept of quantum phase-space (Wigner) distributions for quarks and gluons in the proton. To appreciate their physical content, we analyze the contraints from special relativity on the interpretation of elastic form factors, and examine the physics of the Feynman parton distributions in the proton's rest frame. We relate the quark Wigner functions to the transverse-momentum dependent parton distributions and generalized parton distributions, emphasizing the physical role of the skewness parameter. We show that the Wigner functions allow us to visualize quantum quarks and gluons using the language of classical phase space. We present two examples of the quark Wigner distributions and point out some model-independent features
Energy Technology Data Exchange (ETDEWEB)
Drummond, P D [University of Queensland, St. Lucia, QLD (Australia).Physics Department
1999-07-01
Full text: Quantum optics in Australia has been an active research field for some years. I shall focus on recent developments in quantum and atom optics. Generally, the field as a whole is becoming more and more diverse, as technological developments drive experiments into new areas, and theorists either attempt to explain the new features, or else develop models for even more exotic ideas. The recent developments include quantum solitons, quantum computing, Bose-Einstein condensation, atom lasers, quantum cryptography, and novel tests of quantum mechanics. The talk will briefly cover current progress and outstanding problems in each of these areas. Copyright (1999) Australian Optical Society.
Framing and misperception in public good experiments
DEFF Research Database (Denmark)
Fosgaard, Toke Reinholt; Hansen, Lars Gårn; Wengström, Erik Roland
2017-01-01
Earlier studies have found that framing has substantial impact on the degree of cooperation observed in public good experiments. We show that the way the public good game is framed affects misperceptions about the incentives of the game. Moreover, we show that such framing-induced differences...... in misperceptions are linked to the framing effect on subjects' cooperation behavior. When we do not control for the different levels of misperceptions between frames, we observe a significant framing effect on subjects’ cooperation preferences. However, this framing effect becomes insignificant once we remove...
A generalization of Fermat's principle for classical and quantum systems
Energy Technology Data Exchange (ETDEWEB)
Elsayed, Tarek A., E-mail: T.Elsayed@thphys.uni-heidelberg.de
2014-09-12
Highlights: • Introduces a generalized Fermat principle for many-dimensional dynamical systems. • Deals with the time taken by the system between given initial and final states. • Proposes that if the speed of the system point is constant, the time is an extremum. • Justified for the phase space of harmonic oscillators and the projective Hilbert space. • A counterexample for the motion of a charge in a magnetic field is discussed. - Abstract: The analogy between dynamics and optics had a great influence on the development of the foundations of classical and quantum mechanics. We take this analogy one step further and investigate the validity of Fermat's principle in many-dimensional spaces describing dynamical systems (i.e., the quantum Hilbert space and the classical phase and configuration space). We propose that if the notion of a metric distance is well defined in that space and the velocity of the representative point of the system is an invariant of motion, then a generalized version of Fermat's principle will hold. We substantiate this conjecture for time-independent quantum systems and for a classical system consisting of coupled harmonic oscillators. An exception to this principle is the configuration space of a charged particle in a constant magnetic field; in this case the principle is valid in a frame rotating by half the Larmor frequency, not the stationary lab frame.
A generalization of Fermat's principle for classical and quantum systems
International Nuclear Information System (INIS)
Elsayed, Tarek A.
2014-01-01
Highlights: • Introduces a generalized Fermat principle for many-dimensional dynamical systems. • Deals with the time taken by the system between given initial and final states. • Proposes that if the speed of the system point is constant, the time is an extremum. • Justified for the phase space of harmonic oscillators and the projective Hilbert space. • A counterexample for the motion of a charge in a magnetic field is discussed. - Abstract: The analogy between dynamics and optics had a great influence on the development of the foundations of classical and quantum mechanics. We take this analogy one step further and investigate the validity of Fermat's principle in many-dimensional spaces describing dynamical systems (i.e., the quantum Hilbert space and the classical phase and configuration space). We propose that if the notion of a metric distance is well defined in that space and the velocity of the representative point of the system is an invariant of motion, then a generalized version of Fermat's principle will hold. We substantiate this conjecture for time-independent quantum systems and for a classical system consisting of coupled harmonic oscillators. An exception to this principle is the configuration space of a charged particle in a constant magnetic field; in this case the principle is valid in a frame rotating by half the Larmor frequency, not the stationary lab frame
Media framing and social movements
Vliegenthart, R.; Snow, D.A.; Della Porta, D.; Klandermans, B.; McAdam, D.
2013-01-01
In their study of media content, mass communication scholars commonly rely on Entman's (1993: 52) definition of framing: "[selecting] some aspects of a perceived reality and make them more salient in a communicating text, in such a way as to promote a particular problem definition, causal
MINAMI, Haruo
2016-01-01
For a compact simple Lie group $G$, we show that the element $[G, \\mathcal{L}] \\in \\pi^S_*(S^0)$ represented by the pair $(G, \\mathcal{L})$ is zero, where $\\mathcal{L}$ denotes the left invariant framing of $G$. The proof relies on the method of E. Ossa [Topology, 21 (1982), 315–323].
Handedness differences in information framing.
Jasper, John D; Fournier, Candice; Christman, Stephen D
2014-02-01
Previous research has shown that strength of handedness predicts differences in sensory illusions, Stroop interference, episodic memory, and beliefs about body image. Recent evidence also suggests handedness differences in the susceptibility to common decision biases such as anchoring and sunk cost. The present paper extends this line of work to attribute framing effects. Sixty-three undergraduates were asked to advise a friend concerning the use of a safe allergy medication during pregnancy. A third of the participants received negatively-framed information concerning the fetal risk of the drug (1-3% chance of having a malformed child); another third received positively-framed information (97-99% chance of having a normal child); and the final third received no counseling information and served as the control. Results indicated that, as predicted, inconsistent (mixed)-handers were more responsive than consistent (strong)-handers to information changes and readily update their beliefs. Although not significant, the data also suggested that only inconsistent handers were affected by information framing. Theoretical implications as well as ongoing work in holistic versus analytic processing, contextual sensitivity, and brain asymmetry will be discussed. Copyright © 2013 Elsevier Inc. All rights reserved.
Meta framing and polyphonic structures
DEFF Research Database (Denmark)
Pedersen, Karsten
2017-01-01
in various ways in BT’s 2012 coverage of a doping case involving Riis. In this article I investigate the way in which BT meta frames itself and its own actions in order to show and underline the seriousness with which BT treats sports journalism. The study is part of a recurring Danish project harvesting...
Watson, Andrew B.
2012-01-01
To enhance the quality of the theatre experience, the film industry is interested in achieving higher frame rates for capture and display. In this talk I will describe the basic spatio-temporal sensitivities of human vision, and how they respond to the time sequence of static images that is fundamental to cinematic presentation.
Reference frame for Product Configuration
DEFF Research Database (Denmark)
Ladeby, Klaes Rohde; Oddsson, Gudmundur Valur
2011-01-01
a reference frame for configuration that permits 1) a more precise understanding of a configuration system, 2) a understanding of how the configuration system relate to other systems, and 3) a definition of the basic concepts in configuration. The total configuration system, together with the definition...
Plasma physics in noninertial frames
International Nuclear Information System (INIS)
Thyagaraja, A.; McClements, K. G.
2009-01-01
Equations describing the nonrelativistic motion of a charged particle in an arbitrary noninertial reference frame are derived from the relativistically invariant form of the particle action. It is shown that the equations of motion can be written in the same form in inertial and noninertial frames, with the effective electric and magnetic fields in the latter modified by inertial effects associated with centrifugal and Coriolis accelerations. These modifications depend on the particle charge-to-mass ratio, and also the vorticity, specific kinetic energy, and compressibility of the frame flow. The Newton-Lorentz, Vlasov, and Fokker-Planck equations in such a frame are derived. Reduced models such as gyrokinetic, drift-kinetic, and fluid equations are then derivable from these equations in the appropriate limits, using standard averaging procedures. The results are applied to tokamak plasmas rotating about the machine symmetry axis with a nonrelativistic but otherwise arbitrary toroidal flow velocity. Astrophysical applications of the analysis are also possible since the power of the action principle is such that it can be used to describe relativistic flows in curved spacetime.
Framing the future of fracking
Metze, Tamara
2017-01-01
Hydraulic fracturing is a technology developed to improve and increase the production of natural gas. In many countries, including the Netherlands, it has caused environmental controversies. In these controversies, 'futurity framing' may open up debates for alternative paradigms such as
Frames and generalized shift-invariant systems
DEFF Research Database (Denmark)
Christensen, Ole
2004-01-01
With motivation from the theory of Hilbert-Schmidt operators we review recent topics concerning frames in L 2 (R) and their duals. Frames are generalizations of orthonormal bases in Hilbert spaces. As for an orthonormal basis, a frame allows each element in the underlying Hilbert space...... to be written as an unconditionally convergent infinite linear combination of the frame elements; however, in contrast to the situation for a basis, the coefficients might not be unique. We present the basic facts from frame theory and the motivation for the fact that most recent research concentrates on tight...... frames or dual frame pairs rather than general frames and their canonical dual. The corresponding results for Gabor frames and wavelet frames are discussed in detail....
Fundamental Structure of Loop Quantum Gravity
Han, Muxin; Ma, Yongge; Huang, Weiming
In the recent twenty years, loop quantum gravity, a background independent approach to unify general relativity and quantum mechanics, has been widely investigated. The aim of loop quantum gravity is to construct a mathematically rigorous, background independent, non-perturbative quantum theory for a Lorentzian gravitational field on a four-dimensional manifold. In the approach, the principles of quantum mechanics are combined with those of general relativity naturally. Such a combination provides us a picture of, so-called, quantum Riemannian geometry, which is discrete on the fundamental scale. Imposing the quantum constraints in analogy from the classical ones, the quantum dynamics of gravity is being studied as one of the most important issues in loop quantum gravity. On the other hand, the semi-classical analysis is being carried out to test the classical limit of the quantum theory. In this review, the fundamental structure of loop quantum gravity is presented pedagogically. Our main aim is to help non-experts to understand the motivations, basic structures, as well as general results. It may also be beneficial to practitioners to gain insights from different perspectives on the theory. We will focus on the theoretical framework itself, rather than its applications, and do our best to write it in modern and precise langauge while keeping the presentation accessible for beginners. After reviewing the classical connection dynamical formalism of general relativity, as a foundation, the construction of the kinematical Ashtekar-Isham-Lewandowski representation is introduced in the content of quantum kinematics. The algebraic structure of quantum kinematics is also discussed. In the content of quantum dynamics, we mainly introduce the construction of a Hamiltonian constraint operator and the master constraint project. At last, some applications and recent advances are outlined. It should be noted that this strategy of quantizing gravity can also be extended to
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.)
On the structures of Grassmannian frames
Haas IV, John I.; Casazza, Peter G.
2017-01-01
A common criterion in the design of finite Hilbert space frames is minimal coherence, as this leads to error reduction in various signal processing applications. Frames that achieve minimal coherence relative to all unit-norm frames are called Grassmannian frames, a class which includes the well-known equiangular tight frames. However, the notion of "coherence minimization" varies according to the constraints of the ambient optimization problem, so there are other types of "minimally coherent...
Device-independent two-party cryptography secure against sequential attacks
DEFF Research Database (Denmark)
Kaniewski, Jedrzej; Wehner, Stephanie
2016-01-01
The goal of two-party cryptography is to enable two parties, Alice and Bob, to solve common tasks without the need for mutual trust. Examples of such tasks are private access to a database, and secure identification. Quantum communication enables security for all of these problems in the noisy......-storage model by sending more signals than the adversary can store in a certain time frame. Here, we initiate the study of device-independent (DI) protocols for two-party cryptography in the noisy-storage model. Specifically, we present a relatively easy to implement protocol for a cryptographic building block...... known as weak string erasure and prove its security even if the devices used in the protocol are prepared by the dishonest party. DI two-party cryptography is made challenging by the fact that Alice and Bob do not trust each other, which requires new techniques to establish security. We fully analyse...
Confidence in the safety of blood for transfusion: the effect of message framing.
Farrell, K; Ferguson, E; James, V; Lowe, K C
2001-11-01
Blood transfusion is a universally used, life-saving medical intervention. However, there are increasing concerns among patients about blood safety. This study investigates the effect of message framing, a means of presenting information, on confidence in blood transfusion safety. The same factual information regarding the safety of blood for transfusion was presented to a sample of 254 adult students (donors and nondonors) as either a gain frame (lives saved), a loss frame (lives lost), or a combined frame (a loss frame expressed in a positive context). This provided a basic two-way, between-subjects design with 1) blood donation history (donors vs. nondonors) and 2) message frame (gain, loss, and combined) functioning as the between-groups factors. It was hypothesized that participants would consider blood safer if information was presented as a gain frame. The role of stress appraisals as potential mediators of the framing effect was also explored. As predicted, participants receiving the gain-frame information were significantly more confident of the safety of blood for transfusion than those receiving loss-frame information or both. This was unaffected by donation history or appraisals of stress associated with transfusion. The extent to which blood was considered safe was negatively associated, independently of framing effects, with perceptions that transfusion was threatening. Information about transfusion should be conveyed to patients in a form focusing on the positive, rather than the negative, known facts about the safety of blood.
Quantum robots and quantum computers
Energy Technology Data Exchange (ETDEWEB)
Benioff, P.
1998-07-01
Validation of a presumably universal theory, such as quantum mechanics, requires a quantum mechanical description of systems that carry out theoretical calculations and systems that carry out experiments. The description of quantum computers is under active development. No description of systems to carry out experiments has been given. A small step in this direction is taken here by giving a description of quantum robots as mobile systems with on board quantum computers that interact with different environments. Some properties of these systems are discussed. A specific model based on the literature descriptions of quantum Turing machines is presented.
Quantum computers and quantum computations
International Nuclear Information System (INIS)
Valiev, Kamil' A
2005-01-01
This review outlines the principles of operation of quantum computers and their elements. The theory of ideal computers that do not interact with the environment and are immune to quantum decohering processes is presented. Decohering processes in quantum computers are investigated. The review considers methods for correcting quantum computing errors arising from the decoherence of the state of the quantum computer, as well as possible methods for the suppression of the decohering processes. A brief enumeration of proposed quantum computer realizations concludes the review. (reviews of topical problems)
Control aspects of quantum computing using pure and mixed states
Schulte-Herbrüggen, Thomas; Marx, Raimund; Fahmy, Amr; Kauffman, Louis; Lomonaco, Samuel; Khaneja, Navin; Glaser, Steffen J.
2012-01-01
Steering quantum dynamics such that the target states solve classically hard problems is paramount to quantum simulation and computation. And beyond, quantum control is also essential to pave the way to quantum technologies. Here, important control techniques are reviewed and presented in a unified frame covering quantum computational gate synthesis and spectroscopic state transfer alike. We emphasize that it does not matter whether the quantum states of interest are pure or not. While pure states underly the design of quantum circuits, ensemble mixtures of quantum states can be exploited in a more recent class of algorithms: it is illustrated by characterizing the Jones polynomial in order to distinguish between different (classes of) knots. Further applications include Josephson elements, cavity grids, ion traps and nitrogen vacancy centres in scenarios of closed as well as open quantum systems. PMID:22946034
Control aspects of quantum computing using pure and mixed states.
Schulte-Herbrüggen, Thomas; Marx, Raimund; Fahmy, Amr; Kauffman, Louis; Lomonaco, Samuel; Khaneja, Navin; Glaser, Steffen J
2012-10-13
Steering quantum dynamics such that the target states solve classically hard problems is paramount to quantum simulation and computation. And beyond, quantum control is also essential to pave the way to quantum technologies. Here, important control techniques are reviewed and presented in a unified frame covering quantum computational gate synthesis and spectroscopic state transfer alike. We emphasize that it does not matter whether the quantum states of interest are pure or not. While pure states underly the design of quantum circuits, ensemble mixtures of quantum states can be exploited in a more recent class of algorithms: it is illustrated by characterizing the Jones polynomial in order to distinguish between different (classes of) knots. Further applications include Josephson elements, cavity grids, ion traps and nitrogen vacancy centres in scenarios of closed as well as open quantum systems.
Taking a Quantum Leap in Cyber Deterrence
2010-02-17
frame an adversary‘s rationale and decision calculus. 82 Understanding a group‘s rationale helps frame a strategy for deterrence. Emanuel Adler ...to leverage against America. 8586 Adler adds that when deterrence culture in this context is driven by religious and ethnic- nationalist beliefs...Path to the Quantum Computer. New York: Alfred A. Knopf, 2003. Kapur, S. Paul. "Deterring Nuclear Terrorists." In Complex Deterrence: Strategy in
Chanda, Rajat
1997-01-01
The book discusses the laws of quantum mechanics, several amazing quantum phenomena and some recent progress in understanding the connection between the quantum and the classical worlds. We show how paradoxes arise and how to resolve them. The significance of Bell's theorem and the remarkable experimental results on particle correlations are described in some detail. Finally, the current status of our understanding of quantum theory is summerised.
International Nuclear Information System (INIS)
Rovelli, C.
1996-01-01
I suggest that the common unease with taking quantum mechanics as a fundamental description of nature (the open-quotes measurement problemclose quotes) could derive from the use of an incorrect notion, as the unease with the Lorentz transformations before Einstein derived from the notion of observer-independent time. I suggest that this incorrect notion that generates the unease with quantum mechanics is the notion of open-quotes observer-independent stateclose quotes of a system, or open-quotes observer-independent values of physical quantities.close quotes I reformulate the problem of the open-quotes interpretation of quantum mechanicsclose quotes as the problem of deriving the formalism from a set of simple physical postulates. I consider a reformulation of quantum mechanics in terms of information theory. All systems are assumed to be equivalent, there is no observer-observed distinction, and the theory describes only the information that systems have about each other; nevertheless, the theory is complete
Tomographic Approach in Three-Orthogonal-Basis Quantum Key Distribution
International Nuclear Information System (INIS)
Liang Wen-Ye; Yin Zhen-Qiang; Chen Hua; Li Hong-Wei; Chen Wei; Han Zheng-Fu; Wen Hao
2015-01-01
At present, there is an increasing awareness of some three-orthogonal-basis quantum key distribution protocols, such as, the reference-frame-independent (RFI) protocol and the six-state protocol. For secure key rate estimations of these protocols, there are two methods: one is the conventional approach, and another is the tomographic approach. However, a comparison between these two methods has not been given yet. In this work, with the general model of rotation channel, we estimate the key rate using conventional and tomographic methods respectively. Results show that conventional estimation approach in RFI protocol is equivalent to tomographic approach only in the case of that one of three orthogonal bases is always aligned. In other cases, tomographic approach performs much better than the respective conventional approaches of the RFI protocol and the six-state protocol. Furthermore, based on the experimental data, we illustrate the deep connections between tomography and conventional RFI approach representations. (paper)
Coleman, Piers; Schofield, Andrew J
2005-01-20
As we mark the centenary of Albert Einstein's seminal contribution to both quantum mechanics and special relativity, we approach another anniversary--that of Einstein's foundation of the quantum theory of solids. But 100 years on, the same experimental measurement that puzzled Einstein and his contemporaries is forcing us to question our understanding of how quantum matter transforms at ultra-low temperatures.
Indian Academy of Sciences (India)
In the first part of this article, we had looked at how quantum physics can be harnessed to make the building blocks of a quantum computer. In this concluding part, we look at algorithms which can exploit the power of this computational device, and some practical difficulties in building such a device. Quantum Algorithms.
I, Quantum Robot: Quantum Mind control on a Quantum Computer
Zizzi, Paola
2008-01-01
The logic which describes quantum robots is not orthodox quantum logic, but a deductive calculus which reproduces the quantum tasks (computational processes, and actions) taking into account quantum superposition and quantum entanglement. A way toward the realization of intelligent quantum robots is to adopt a quantum metalanguage to control quantum robots. A physical implementation of a quantum metalanguage might be the use of coherent states in brain signals.
Ultra-fast framing camera tube
Kalibjian, Ralph
1981-01-01
An electronic framing camera tube features focal plane image dissection and synchronized restoration of the dissected electron line images to form two-dimensional framed images. Ultra-fast framing is performed by first streaking a two-dimensional electron image across a narrow slit, thereby dissecting the two-dimensional electron image into sequential electron line images. The dissected electron line images are then restored into a framed image by a restorer deflector operated synchronously with the dissector deflector. The number of framed images on the tube's viewing screen is equal to the number of dissecting slits in the tube. The distinguishing features of this ultra-fast framing camera tube are the focal plane dissecting slits, and the synchronously-operated restorer deflector which restores the dissected electron line images into a two-dimensional framed image. The framing camera tube can produce image frames having high spatial resolution of optical events in the sub-100 picosecond range.
Variance based OFDM frame synchronization
Directory of Open Access Journals (Sweden)
Z. Fedra
2012-04-01
Full Text Available The paper deals with a new frame synchronization scheme for OFDM systems and calculates the complexity of this scheme. The scheme is based on the computing of the detection window variance. The variance is computed in two delayed times, so a modified Early-Late loop is used for the frame position detection. The proposed algorithm deals with different variants of OFDM parameters including guard interval, cyclic prefix, and has good properties regarding the choice of the algorithm's parameters since the parameters may be chosen within a wide range without having a high influence on system performance. The verification of the proposed algorithm functionality has been performed on a development environment using universal software radio peripheral (USRP hardware.
Quantum Logic and Quantum Reconstruction
Stairs, Allen
2015-01-01
Quantum logic understood as a reconstruction program had real successes and genuine limitations. This paper offers a synopsis of both and suggests a way of seeing quantum logic in a larger, still thriving context.
Quantum dynamics of quantum bits
International Nuclear Information System (INIS)
Nguyen, Bich Ha
2011-01-01
The theory of coherent oscillations of the matrix elements of the density matrix of the two-state system as a quantum bit is presented. Different calculation methods are elaborated in the case of a free quantum bit. Then the most appropriate methods are applied to the study of the density matrices of the quantum bits interacting with a classical pumping radiation field as well as with the quantum electromagnetic field in a single-mode microcavity. The theory of decoherence of a quantum bit in Markovian approximation is presented. The decoherence of a quantum bit interacting with monoenergetic photons in a microcavity is also discussed. The content of the present work can be considered as an introduction to the study of the quantum dynamics of quantum bits. (review)
Predicting the Strength of Online News Frames
Directory of Open Access Journals (Sweden)
Hrvoje Jakopović
2017-10-01
Full Text Available Framing theory is one of the most significant approaches to understanding media and their potential impact on publics. Leaving aside that fact, the author finds that publicity effects seem to be dispersed and difficult to catch for public relations. This article employs a specific research design, which could be applied to public relations practice, namely with a view to observing correlations between specific media frames and individual frames. The approach is based on the typology of news frames. The author attributes negative, positive and neutral determinants to the types of frames in his empirical research. Online news regarding three transport organizations and the accompanying user comments (identified as negative, positive and neutral are analysed by means of the method of content and sentiment analysis. The author recognizes user comments and reviews as individual frames that take part in the creation of online image. Furthermore, he identifies the types of media frames as well as individual frames manifested as image, and undertakes correlation research in order to establish their prediction potential. The results expose the most frequently used types of media frames concerning the transport domain. The media are keen to report through the attribution of responsibility frame, and after that, through the economic frame and the conflict frame, but, on the other hand, they tend to neglect the human interest frame and the morality frame. The results show that specific types of news frames enable better prediction of user reactions. The economic frame and the human interest frame therefore represent the most predictable types of frame.
Sovereignty Frames and Sovereignty Claims
Walker, Neil
2013-01-01
This essay argues that much of the contemporary confusion and controversy over the meaning and continuing utility of the concept of sovereignty stems from a failure to distinguish between sovereignty as a deep framing device for making sense of the modern legal and political word on the one hand, and the particular claims which are made on behalf of particular institutions, agencies, rules or other entities to possess sovereign authority on the other. The essay begins by providing a basic acc...
Synchronization in Quantum Key Distribution Systems
Directory of Open Access Journals (Sweden)
Anton Pljonkin
2017-10-01
Full Text Available In the description of quantum key distribution systems, much attention is paid to the operation of quantum cryptography protocols. The main problem is the insufficient study of the synchronization process of quantum key distribution systems. This paper contains a general description of quantum cryptography principles. A two-line fiber-optic quantum key distribution system with phase coding of photon states in transceiver and coding station synchronization mode was examined. A quantum key distribution system was built on the basis of the scheme with automatic compensation of polarization mode distortions. Single-photon avalanche diodes were used as optical radiation detecting devices. It was estimated how the parameters used in quantum key distribution systems of optical detectors affect the detection of the time frame with attenuated optical pulse in synchronization mode with respect to its probabilistic and time-domain characteristics. A design method was given for the process that detects the time frame that includes an optical pulse during synchronization. This paper describes the main quantum communication channel attack methods by removing a portion of optical emission. This paper describes the developed synchronization algorithm that takes into account the time required to restore the photodetector’s operation state after the photon has been registered during synchronization. The computer simulation results of the developed synchronization algorithm were analyzed. The efficiency of the developed algorithm with respect to synchronization process protection from unauthorized gathering of optical emission is demonstrated herein.
Zurek, Wojciech Hubert
2009-03-01
Quantum Darwinism describes the proliferation, in the environment, of multiple records of selected states of a quantum system. It explains how the quantum fragility of a state of a single quantum system can lead to the classical robustness of states in their correlated multitude; shows how effective `wave-packet collapse' arises as a result of the proliferation throughout the environment of imprints of the state of the system; and provides a framework for the derivation of Born's rule, which relates the probabilities of detecting states to their amplitudes. Taken together, these three advances mark considerable progress towards settling the quantum measurement problem.
Orthogonal Multiwavelet Frames in L2Rd
Directory of Open Access Journals (Sweden)
Liu Zhanwei
2012-01-01
Full Text Available We characterize the orthogonal frames and orthogonal multiwavelet frames in L2Rd with matrix dilations of the form (Df(x=detAf(Ax, where A is an arbitrary expanding d×d matrix with integer coefficients. Firstly, through two arbitrarily multiwavelet frames, we give a simple construction of a pair of orthogonal multiwavelet frames. Then, by using the unitary extension principle, we present an algorithm for the construction of arbitrarily many orthogonal multiwavelet tight frames. Finally, we give a general construction algorithm for orthogonal multiwavelet tight frames from a scaling function.
Spacetime transformations from a uniformly accelerated frame
International Nuclear Information System (INIS)
Friedman, Yaakov; Scarr, Tzvi
2013-01-01
We use the generalized Fermi–Walker transport to construct a one-parameter family of inertial frames which are instantaneously comoving to a uniformly accelerated observer. We explain the connection between our approach and that of Mashhoon. We show that our solutions of uniformly accelerated motion have constant acceleration in the comoving frame. Assuming the weak hypothesis of locality, we obtain local spacetime transformations from a uniformly accelerated frame K′ to an inertial frame K. The spacetime transformations between two uniformly accelerated frames with the same acceleration are Lorentz. We compute the metric at an arbitrary point of a uniformly accelerated frame. (paper)
Quadratic independence of coordinate functions of certain ...
Indian Academy of Sciences (India)
... are `quadratically independent' in the sense that they do not satisfy any nontrivial homogeneous quadratic relations among them. Using this, it is proved that there is no genuine compact quantum group which can act faithfully on C ( M ) such that the action leaves invariant the linear span of the above coordinate functions.
Mars Science Laboratory Frame Manager for Centralized Frame Tree Database and Target Pointing
Kim, Won S.; Leger, Chris; Peters, Stephen; Carsten, Joseph; Diaz-Calderon, Antonio
2013-01-01
The FM (Frame Manager) flight software module is responsible for maintaining the frame tree database containing coordinate transforms between frames. The frame tree is a proper tree structure of directed links, consisting of surface and rover subtrees. Actual frame transforms are updated by their owner. FM updates site and saved frames for the surface tree. As the rover drives to a new area, a new site frame with an incremented site index can be created. Several clients including ARM and RSM (Remote Sensing Mast) update their related rover frames that they own. Through the onboard centralized FM frame tree database, client modules can query transforms between any two frames. Important applications include target image pointing for RSM-mounted cameras and frame-referenced arm moves. The use of frame tree eliminates cumbersome, error-prone calculations of coordinate entries for commands and thus simplifies flight operations significantly.
Scopes and limits of modality in quantum mechanics
International Nuclear Information System (INIS)
Domenech, G.; Freytes, H.; de Ronde, C.
2006-01-01
We develop an algebraic frame for the simultaneous treatment of actual and possible properties of quantum systems. We show that, in spite of the fact that the language is enriched with the addition of a modal operator to the orthomodular structure, contextuality remains a central feature of quantum systems. (Abstract Copyright [2006], Wiley Periodicals, Inc.)
Scopes and limits of modality in quantum mechanics
Energy Technology Data Exchange (ETDEWEB)
Domenech, G. [Instituto de Astronomia y Fisica del Espacio (IAFE), Buenos Aires (Argentina); Freytes, H. [Dipartimento di Scienze e Pedagogiche e Filosofiche, Universita degli Studi di Cagliari, Cagliari (Italy); de Ronde, C. [Center Leo Apostel (CLEA) and Foundations of the Exact Sciences (FUND), Brussels Free University, Brussels (Belgium)
2006-12-15
We develop an algebraic frame for the simultaneous treatment of actual and possible properties of quantum systems. We show that, in spite of the fact that the language is enriched with the addition of a modal operator to the orthomodular structure, contextuality remains a central feature of quantum systems. (Abstract Copyright [2006], Wiley Periodicals, Inc.)
Classical-Quantum Correspondence by Means of Probability Densities
Vegas, Gabino Torres; Morales-Guzman, J. D.
1996-01-01
Within the frame of the recently introduced phase space representation of non relativistic quantum mechanics, we propose a Lagrangian from which the phase space Schrodinger equation can be derived. From that Lagrangian, the associated conservation equations, according to Noether's theorem, are obtained. This shows that one can analyze quantum systems completely in phase space as it is done in coordinate space, without additional complications.
A critical analysis of the quantum theory of measurement
International Nuclear Information System (INIS)
Fer, F.
1984-01-01
Keeping strictly in the positivist and probabilistic, hence hilbertian frame of Quantum Mechanics, the author tries to ascertain whether or not Quantum Mechanics, starting from its axioms, reaches the aim of any physical theory, that is, comparison with experiment. The answer is: no, as long as it keeps close to the existing axiomatics, and also to accurate mathematics. (Auth.)
International Nuclear Information System (INIS)
Kouwenhoven, L.; Marcus, C.
1998-01-01
Quantum dots are man-made ''droplets'' of charge that can contain anything from a single electron to a collection of several thousand. Their typical dimensions range from nanometres to a few microns, and their size, shape and interactions can be precisely controlled through the use of advanced nanofabrication technology. The physics of quantum dots shows many parallels with the behaviour of naturally occurring quantum systems in atomic and nuclear physics. Indeed, quantum dots exemplify an important trend in condensed-matter physics in which researchers study man-made objects rather than real atoms or nuclei. As in an atom, the energy levels in a quantum dot become quantized due to the confinement of electrons. With quantum dots, however, an experimentalist can scan through the entire periodic table by simply changing a voltage. In this article the authors describe how quantum dots make it possible to explore new physics in regimes that cannot otherwise be accessed in the laboratory. (UK)
From quantum foundations to applications and back.
Gisin, Nicolas; Fröwis, Florian
2018-07-13
Quantum non-locality has been an extremely fruitful subject of research, leading the scientific revolution towards quantum information science, in particular, to device-independent quantum information processing. We argue that the time is ripe to work on another basic problem in the foundations of quantum physics, the quantum measurement problem, which should produce good physics in theoretical, mathematical, experimental and applied physics. We briefly review how quantum non-locality contributed to physics (including some outstanding open problems) and suggest ways in which questions around macroscopic quantumness could equally contribute to all aspects of physics.This article is part of a discussion meeting issue 'Foundations of quantum mechanics and their impact on contemporary society'. © 2018 The Author(s).
Quantum generalisation of feedforward neural networks
Wan, Kwok Ho; Dahlsten, Oscar; Kristjánsson, Hlér; Gardner, Robert; Kim, M. S.
2017-09-01
We propose a quantum generalisation of a classical neural network. The classical neurons are firstly rendered reversible by adding ancillary bits. Then they are generalised to being quantum reversible, i.e., unitary (the classical networks we generalise are called feedforward, and have step-function activation functions). The quantum network can be trained efficiently using gradient descent on a cost function to perform quantum generalisations of classical tasks. We demonstrate numerically that it can: (i) compress quantum states onto a minimal number of qubits, creating a quantum autoencoder, and (ii) discover quantum communication protocols such as teleportation. Our general recipe is theoretical and implementation-independent. The quantum neuron module can naturally be implemented photonically.
Simulation of quantum dynamics with integrated photonics
Sansoni, Linda; Sciarrino, Fabio; Mataloni, Paolo; Crespi, Andrea; Ramponi, Roberta; Osellame, Roberto
2012-12-01
In recent years, quantum walks have been proposed as promising resources for the simulation of physical quantum systems. In fact it is widely adopted to simulate quantum dynamics. Up to now single particle quantum walks have been experimentally demonstrated by different approaches, while only few experiments involving many-particle quantum walks have been realized. Here we simulate the 2-particle dynamics on a discrete time quantum walk, built on an array of integrated waveguide beam splitters. The polarization independence of the quantum walk circuit allowed us to exploit the polarization entanglement to encode the symmetry of the two-photon wavefunction, thus the bunching-antibunching behavior of non interacting bosons and fermions has been simulated. We have also characterized the possible distinguishability and decoherence effects arising in such a structure. This study is necessary in view of the realization of a quantum simulator based on an integrated optical array built on a large number of beam splitters.
Quantum information. Teleporation - cryptography - quantum computer
International Nuclear Information System (INIS)
Breuer, Reinhard
2010-01-01
The following topics are dealt with: Reality in the test house, quantum teleportation, 100 years of quantum theory, the reality of quanta, interactionless quantum measurement, rules for quantum computers, quantum computers with ions, spintronics with diamond, the limits of the quantum computers, a view into the future of quantum optics. (HSI)
Device-Independent Certification of a Nonprojective Qubit Measurement
Gómez, Esteban S.; Gómez, Santiago; González, Pablo; Cañas, Gustavo; Barra, Johanna F.; Delgado, Aldo; Xavier, Guilherme B.; Cabello, Adán; Kleinmann, Matthias; Vértesi, Tamás; Lima, Gustavo
2016-12-01
Quantum measurements on a two-level system can have more than two independent outcomes, and in this case, the measurement cannot be projective. Measurements of this general type are essential to an operational approach to quantum theory, but so far, the nonprojective character of a measurement can only be verified experimentally by already assuming a specific quantum model of parts of the experimental setup. Here, we overcome this restriction by using a device-independent approach. In an experiment on pairs of polarization-entangled photonic qubits we violate by more than 8 standard deviations a Bell-like correlation inequality that is valid for all sets of two-outcome measurements in any dimension. We combine this with a device-independent verification that the system is best described by two qubits, which therefore constitutes the first device-independent certification of a nonprojective quantum measurement.
A Novel Quantum Video Steganography Protocol with Large Payload Based on MCQI Quantum Video
Qu, Zhiguo; Chen, Siyi; Ji, Sai
2017-11-01
As one of important multimedia forms in quantum network, quantum video attracts more and more attention of experts and scholars in the world. A secure quantum video steganography protocol with large payload based on the video strip encoding method called as MCQI (Multi-Channel Quantum Images) is proposed in this paper. The new protocol randomly embeds the secret information with the form of quantum video into quantum carrier video on the basis of unique features of video frames. It exploits to embed quantum video as secret information for covert communication. As a result, its capacity are greatly expanded compared with the previous quantum steganography achievements. Meanwhile, the new protocol also achieves good security and imperceptibility by virtue of the randomization of embedding positions and efficient use of redundant frames. Furthermore, the receiver enables to extract secret information from stego video without retaining the original carrier video, and restore the original quantum video as a follow. The simulation and experiment results prove that the algorithm not only has good imperceptibility, high security, but also has large payload.
Quantum symmetry in quantum theory
International Nuclear Information System (INIS)
Schomerus, V.
1993-02-01
Symmetry concepts have always been of great importance for physical problems like explicit calculations, classification or model building. More recently, new 'quantum symmetries' ((quasi) quantum groups) attracted much interest in quantum theory. It is shown that all these quantum symmetries permit a conventional formulation as symmetry in quantum mechanics. Symmetry transformations can act on the Hilbert space H of physical states such that the ground state is invariant and field operators transform covariantly. Models show that one must allow for 'truncation' in the tensor product of representations of a quantum symmetry. This means that the dimension of the tensor product of two representations of dimension σ 1 and σ 2 may be strictly smaller than σ 1 σ 2 . Consistency of the transformation law of field operators local braid relations leads us to expect, that (weak) quasi quantum groups are the most general symmetries in local quantum theory. The elements of the R-matrix which appears in these local braid relations turn out to be operators on H in general. It will be explained in detail how examples of field algebras with weak quasi quantum group symmetry can be obtained. Given a set of observable field with a finite number of superselection sectors, a quantum symmetry together with a complete set of covariant field operators which obey local braid relations are constructed. A covariant transformation law for adjoint fields is not automatic but will follow when the existence of an appropriate antipode is assumed. At the example of the chiral critical Ising model, non-uniqueness of the quantum symmetry will be demonstrated. Generalized quantum symmetries yield examples of gauge symmetries in non-commutative geometry. Quasi-quantum planes are introduced as the simplest examples of quasi-associative differential geometry. (Weak) quasi quantum groups can act on them by generalized derivations much as quantum groups do in non-commutative (differential-) geometry
Quantum algebraic representation of localization and motion of a Dirac electron
International Nuclear Information System (INIS)
Jaekel, Marc-Thierry; Reynaud, Serge
2001-01-01
Quantum algebraic observables representing localization in space-time of a Dirac electron are defined. Inertial motion of the electron is represented in the quantum algebra with electron mass acting as the generator of motion. Since transformations to uniformly accelerated frames are naturally included in this conformally invariant description, the quantum algebra is also able to deal with uniformly accelerated motion
Benchmarking gate-based quantum computers
Michielsen, Kristel; Nocon, Madita; Willsch, Dennis; Jin, Fengping; Lippert, Thomas; De Raedt, Hans
2017-11-01
With the advent of public access to small gate-based quantum processors, it becomes necessary to develop a benchmarking methodology such that independent researchers can validate the operation of these processors. We explore the usefulness of a number of simple quantum circuits as benchmarks for gate-based quantum computing devices and show that circuits performing identity operations are very simple, scalable and sensitive to gate errors and are therefore very well suited for this task. We illustrate the procedure by presenting benchmark results for the IBM Quantum Experience, a cloud-based platform for gate-based quantum computing.
International Nuclear Information System (INIS)
Uiler, Dzh.
1982-01-01
General approach to the structure of the Universe is discussed. Two properties of physical laws: symmetry and changeability are considered from this view point. Each physical law permits simpler formulation in the notion of symmetry. But the simplicity of this description conceals interval mechanisms which make up the base of the physical law. The problem of physical law stability is analyzed. It is concluded that unrestricted changeability is the main property of physics. Primary attention is paid to the problem of ''quantum and Universe''. The effect of measuring process on the experimental results is the most difficult problem of quantum mechanisms. The quantum principle rejected an attempt to conceptually present the reality as it is pictured independently from its observation and it made the description of the Universe structure still more complicated and confused
Energy Technology Data Exchange (ETDEWEB)
Pinto-Neto, N.; Santini, E. Sergio. E-mail: nelsonpn@lafex.cbpf.br; santini@lafex.cbpf.br
2000-12-01
We consider quantum geometrodynamics and parametrized quantum field theories in the frame-work of the Bohm-de Broglie interpretation. In the first case, and following the lines of our previous work, where a Hamiltonian formalism for the bohmian trajectories was constructed, we show the consistency of the theory for any quantum potential, completing the scenarios for canonical quantum cosmology presented there. In the latter case, we prove the consistency of scalar field theory in Minkowski spacetime for any quantum potential, and we show, using this alternative Hamiltonian method, a concrete example already known in the literature where Lorentz invariance of individual events is broken. (author)
Characterization of Oblique Dual Frame Pairs
DEFF Research Database (Denmark)
Christensen, Ole; Eldar, Yonina
2006-01-01
Given a frame for a subspace W of a Hilbert space H, we consider all possible families of oblique dual frame vectors on an appropriately chosen subspace V. In place of the standard description, which involves computing the pseudoinverse of the frame operator, we develop an alternative characteriz...... for the case of shift-invariant spaces with a single generator. The theory is also adapted to the standard frame setting in which the original and dual frames are defined on the same space. Copyright (C) 2006 Hindawi Publishing Corporation. All rights reserved.......Given a frame for a subspace W of a Hilbert space H, we consider all possible families of oblique dual frame vectors on an appropriately chosen subspace V. In place of the standard description, which involves computing the pseudoinverse of the frame operator, we develop an alternative...
International Nuclear Information System (INIS)
Kalibjian, R.
1978-01-01
The optoelectronic framing-camera tube described is capable of recording two-dimensional image frames with high spatial resolution in the <100-ps range. Framing is performed by streaking a two-dimensional electron image across narrow slits. The resulting dissected electron line images from the slits are restored into framed images by a restorer deflector operating synchronously with the dissector deflector. The number of framed images on the tube's viewing screen equals the number of dissecting slits in the tube. Performance has been demonstrated in a prototype tube by recording 135-ps-duration framed images of 2.5-mm patterns at the cathode. The limitation in the framing speed is in the external drivers for the deflectors and not in the tube design characteristics. Faster frame speeds in the <100-ps range can be obtained by use of faster deflection drivers
Mercury's Reference Frames After the MESSENGER Mission
Stark, A.; Oberst, J.; Preusker, F.; Burmeister, S.; Steinbrügge, G.; Hussmann, H.
2018-05-01
We provide an overview of Mercury's reference frames based on MESSENGER observations. We discuss the dynamical, the principal-axes, the ellipsoid, as well as the cartographic frame, which was adopted for MESSENGER data products.
Device-independent entanglement certification of all entangled states
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...
Quantum potentiality revisited
Jaeger, Gregg
2017-10-01
Heisenberg offered an interpretation of the quantum state which made use of a quantitative version of an earlier notion, , of Aristotle by both referring to it using its Latin name, potentia, and identifying its qualitative aspect with . The relationship between this use and Aristotle's notion was not made by Heisenberg in full detail, beyond noting their common character: that of signifying the system's objective capacity to be found later to possess a property in actuality. For such actualization, Heisenberg required measurement to have taken place, an interaction with external systems that disrupts the otherwise independent, natural evolution of the quantum system. The notion of state actualization was later taken up by others, including Shimony, in the search for a law-like measurement process. Yet, the relation of quantum potentiality to Aristotle's original notion has been viewed as mainly terminological, even by those who used it thus. Here, I reconsider the relation of Heisenberg's notion to Aristotle's and show that it can be explicated in greater specificity than Heisenberg did. This is accomplished through the careful consideration of the role of potentia in physical causation and explanation, and done in order to provide a fuller understanding of this aspect of Heisenberg's approach to quantum mechanics. Most importantly, it is pointed out that Heisenberg's requirement of an external intervention during measurement that disrupts the otherwise independent, natural evolution of the quantum system is in accord with Aristotle's characterization of spontaneous causation. Thus, the need for a teleological understanding of the actualization of potentia, an often assumed requirement that has left this fundamental notion neglected, is seen to be spurious. This article is part of the themed issue `Second quantum revolution: foundational questions'.
Quantum potentiality revisited.
Jaeger, Gregg
2017-11-13
Heisenberg offered an interpretation of the quantum state which made use of a quantitative version of an earlier notion, [Formula: see text], of Aristotle by both referring to it using its Latin name, potentia , and identifying its qualitative aspect with [Formula: see text] The relationship between this use and Aristotle's notion was not made by Heisenberg in full detail, beyond noting their common character: that of signifying the system's objective capacity to be found later to possess a property in actuality. For such actualization, Heisenberg required measurement to have taken place, an interaction with external systems that disrupts the otherwise independent, natural evolution of the quantum system. The notion of state actualization was later taken up by others, including Shimony, in the search for a law-like measurement process. Yet, the relation of quantum potentiality to Aristotle's original notion has been viewed as mainly terminological, even by those who used it thus. Here, I reconsider the relation of Heisenberg's notion to Aristotle's and show that it can be explicated in greater specificity than Heisenberg did. This is accomplished through the careful consideration of the role of potentia in physical causation and explanation, and done in order to provide a fuller understanding of this aspect of Heisenberg's approach to quantum mechanics. Most importantly, it is pointed out that Heisenberg's requirement of an external intervention during measurement that disrupts the otherwise independent, natural evolution of the quantum system is in accord with Aristotle's characterization of spontaneous causation. Thus, the need for a teleological understanding of the actualization of potentia, an often assumed requirement that has left this fundamental notion neglected, is seen to be spurious.This article is part of the themed issue 'Second quantum revolution: foundational questions'. © 2017 The Author(s).
Lütkenhaus, N.; Shields, A. J.
2009-04-01
work done to date relates to point-to-point links. Another recent advance has been the development of trusted networks for QKD. This is important for further increasing the range of the technology, and for overcoming denial-of-service attacks on an individual link. It is interesting to see that the optimization of QKD devices differs for point-to-point and network applications. Network operation is essential for widespread adoption of the technology, as it can dramatically reduce the deployment costs and allow connection flexibility. Also important is the multiplexing of the quantum signals with conventional network traffic. For the future, quantum repeaters should be developed for longer range links. On the theoretical side, different approaches to security proofs have recently started to converge, offering several paradigms of the same basic idea. Our improved theoretical understanding places more stringent demands on the QKD devices. We are aware by now that finite size effects in key generation arise not only from parameter estimation. It will not be possible to generate a key from just a few hundred received signals. It is a stimulating challenge for the theory of security proofs to develop lean proof strategies that work with finite signal block sizes. As QKD advances to a real-world cryptographic solution, side channel attacks must be carefully analysed. Theoretical security proofs for QKD schemes are so far based on physical models of these devices. It is in the nature of models that any real implementation will deviate from this model, creating a potential weakness for an eavesdropper to exploit. There are two solutions to this problem: the traditional path of refining the models to reduce the deviations, or the radically different approach of device-independent security proofs, in which none or only a few well controlled assumptions about the devices are made. Clearly, it is desirable to find security proofs that require only minimal or fairly general model
Intrinsic irreversibility in quantum theory
International Nuclear Information System (INIS)
Prigogine, I.; Petrosky, T.Y.
1987-01-01
Quantum theory has a dual structure: while solutions of the Schroedinger equation evolve in a deterministic and time reversible way, measurement introduces irreversibility and stochasticity. This presents a contrast to Bohr-Sommerfeld-Einstein theory, in which transitions between quantum states are associated with spontaneous and induced transitions, defined in terms of stochastic processes. A new form of quantum theory is presented here, which contains an intrinsic form of irreversibility, independent of observation. This new form applies to situations corresponding to a continuous spectrum and to quantum states with finite life time. The usual non-commutative algebra associated to quantum theory is replaced by more general algebra, in which operators are also non-distributive. Our approach leads to a number of predictions, which hopefully may be verified or refuted in the next years. (orig.)
Entanglement in open quantum systems
International Nuclear Information System (INIS)
Isar, A.
2007-01-01
In the framework of the theory of open systems based on quantum dynamical semigroups, we solve the master equation for two independent bosonic oscillators interacting with an environment in the asymptotic long-time regime. We give a description of the continuous-variable entanglement in terms of the covariance matrix of the quantum states of the considered system for an arbitrary Gaussian input state. Using the Peres-Simon necessary and sufficient condition for separability of two-mode Gaussian states, we show that the two non-interacting systems immersed in a common environment and evolving under a Markovian, completely positive dynamics become asymptotically entangled for certain environments, so that their non-local quantum correlations exist in the long-time regime. (author) Key words: quantum information theory, open systems, quantum entanglement, inseparable states
Quantum games as quantum types
Delbecque, Yannick
In this thesis, we present a new model for higher-order quantum programming languages. The proposed model is an adaptation of the probabilistic game semantics developed by Danos and Harmer [DH02]: we expand it with quantum strategies which enable one to represent quantum states and quantum operations. Some of the basic properties of these strategies are established and then used to construct denotational semantics for three quantum programming languages. The first of these languages is a formalisation of the measurement calculus proposed by Danos et al. [DKP07]. The other two are new: they are higher-order quantum programming languages. Previous attempts to define a denotational semantics for higher-order quantum programming languages have failed. We identify some of the key reasons for this and base the design of our higher-order languages on these observations. The game semantics proposed in this thesis is the first denotational semantics for a lambda-calculus equipped with quantum types and with extra operations which allow one to program quantum algorithms. The results presented validate the two different approaches used in the design of these two new higher-order languages: a first one where quantum states are used through references and a second one where they are introduced as constants in the language. The quantum strategies presented in this thesis allow one to understand the constraints that must be imposed on quantum type systems with higher-order types. The most significant constraint is the fact that abstraction over part of the tensor product of many unknown quantum states must not be allowed. Quantum strategies are a new mathematical model which describes the interaction between classical and quantum data using system-environment dialogues. The interactions between the different parts of a quantum system are described using the rich structure generated by composition of strategies. This approach has enough generality to be put in relation with other
Controlled Photon Switch Assisted by Coupled Quantum Dots
Luo, Ming-Xing; Ma, Song-Ya; Chen, Xiu-Bo; Wang, Xiaojun
2015-01-01
Quantum switch is a primitive element in quantum network communication. In contrast to previous switch schemes on one degree of freedom (DOF) of quantum systems, we consider controlled switches of photon system with two DOFs. These controlled photon switches are constructed by exploring the optical selection rules derived from the quantum-dot spins in one-sided optical microcavities. Several double controlled-NOT gate on different joint systems are greatly simplified with an auxiliary DOF of the controlling photon. The photon switches show that two DOFs of photons can be independently transmitted in quantum networks. This result reduces the quantum resources for quantum network communication. PMID:26095049
Mechanical Energy Change in Inertial Reference Frames
Ghanbari, Saeed
2016-01-01
The mechanical energy change of a system in an inertial frame of reference equals work done by the total nonconservative force in the same frame. This relation is covariant under the Galilean transformations from inertial frame S to S', where S' moves with constant velocity relative to S. In the presence of nonconservative forces, such as normal…
Framing, intentions, and trust-choice incompatibility
Keren, G.B.
2007-01-01
The present paper examines how framing of messages and the intentions inferred from different—positive vs. negative—framings, interact with the development of trust. Empirical evidence is presented showing that different, logically equivalent, frames are supposedly interpreted as implying different
Inertial reference frames and gravitational forces
International Nuclear Information System (INIS)
Santavy, I.
1981-01-01
The connection between different definitions of inertial, i.e. fundamental, reference frames and the corresponding characterisation of gravitational fields by gravitational forces are considered from the point of view of their possible interpretation in university introductory courses. The introduction of a special class of reference frames, denoted 'mixed reference frames' is proposed and discussed. (author)
Computable Frames in Computable Banach Spaces
Directory of Open Access Journals (Sweden)
S.K. Kaushik
2016-06-01
Full Text Available We develop some parts of the frame theory in Banach spaces from the point of view of Computable Analysis. We define computable M-basis and use it to construct a computable Banach space of scalar valued sequences. Computable Xd frames and computable Banach frames are also defined and computable versions of sufficient conditions for their existence are obtained.
Information Leakage from Logically Equivalent Frames
Sher, Shlomi; McKenzie, Craig R. M.
2006-01-01
Framing effects are said to occur when equivalent frames lead to different choices. However, the equivalence in question has been incompletely conceptualized. In a new normative analysis of framing effects, we complete the conceptualization by introducing the notion of information equivalence. Information equivalence obtains when no…
Influence of framing on medical decision making
Feng, Jun; Gong, Jingjing; Huang, Yonghua; Wei, Yazhou; Zhang, Weiwei; Zhang, Yan
2013-01-01
Numerous studies have demonstrated the robustness of the framing effect in a variety of contexts, especially in medical decision making. Unfortunately, research is still inconsistent as to how so many variables impact framing effects in medical decision making. Additionally, much attention should be paid to the framing effect not only in hypothetical scenarios but also in clinical experience.
Influence of framing on medical decision making.
Gong, Jingjing; Zhang, Yan; Feng, Jun; Huang, Yonghua; Wei, Yazhou; Zhang, Weiwei
2013-01-01
Numerous studies have demonstrated the robustness of the framing effect in a variety of contexts, especially in medical decision making. Unfortunately, research is still inconsistent as to how so many variables impact framing effects in medical decision making. Additionally, much attention should be paid to the framing effect not only in hypothetical scenarios but also in clinical experience.
Influence of framing on medical decision making
Gong, Jingjing; Zhang, Yan; Feng, Jun; Huang, Yonghua; Wei, Yazhou; Zhang, Weiwei
2013-01-01
Numerous studies have demonstrated the robustness of the framing effect in a variety of contexts, especially in medical decision making. Unfortunately, research is still inconsistent as to how so many variables impact framing effects in medical decision making. Additionally, much attention should be paid to the framing effect not only in hypothetical scenarios but also in clinical experience. PMID:27034630
Evaluation and the Framing of Race
House, Ernest R.
2017-01-01
Racial framing can have strong effects on programs, policies, and even evaluations. Racial framing developed as a justification for the exploitation of minorities and has been a primary causal factor in the persistence of racism. By being aware of its pattern, structure, origins, and how racial framing generates effects, we can significantly…
2010-01-01
... 10 Energy 4 2010-01-01 2010-01-01 false Time frames. 710.35 Section 710.35 Energy DEPARTMENT OF... Matter or Special Nuclear Material Miscellaneous § 710.35 Time frames. Statements of time established for processing aspects of a case under this subpart are the agency's desired time frames in implementing the...
21 CFR 886.5842 - Spectacle frame.
2010-04-01
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Spectacle frame. 886.5842 Section 886.5842 Food... DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5842 Spectacle frame. (a) Identification. A spectacle frame is a device made of metal or plastic intended to hold prescription spectacle lenses worn by a...
Common Frame of Reference and social justice
Hesselink, M.W.; Satyanarayana, R.
2009-01-01
The article "Common Frame of Reference and Social Justice" by Martijn W. Hesselink evaluates the Draft Common Frame of Reference (DCFR) of social justice. It discusses the important areas, namely a common frame of Reference in a broad sense, social justice and contract law, private law and
Quantum complexity of graph and algebraic problems
International Nuclear Information System (INIS)
Doern, Sebastian
2008-01-01
This thesis is organized as follows: In Chapter 2 we give some basic notations, definitions and facts from linear algebra, graph theory, group theory and quantum computation. In Chapter 3 we describe three important methods for the construction of quantum algorithms. We present the quantum search algorithm by Grover, the quantum amplitude amplification and the quantum walk search technique by Magniez et al. These three tools are the basis for the development of our new quantum algorithms for graph and algebra problems. In Chapter 4 we present two tools for proving quantum query lower bounds. We present the quantum adversary method by Ambainis and the polynomial method introduced by Beals et al. The quantum adversary tool is very useful to prove good lower bounds for many graph and algebra problems. The part of the thesis containing the original results is organized in two parts. In the first part we consider the graph problems. In Chapter 5 we give a short summary of known quantum graph algorithms. In Chapter 6 to 8 we study the complexity of our new algorithms for matching problems, graph traversal and independent set problems on quantum computers. In the second part of our thesis we present new quantum algorithms for algebraic problems. In Chapter 9 to 10 we consider group testing problems and prove quantum complexity bounds for important problems from linear algebra. (orig.)
General Quantum Interference Principle and Duality Computer
International Nuclear Information System (INIS)
Long Guilu
2006-01-01
In this article, we propose a general principle of quantum interference for quantum system, and based on this we propose a new type of computing machine, the duality computer, that may outperform in principle both classical computer and the quantum computer. According to the general principle of quantum interference, the very essence of quantum interference is the interference of the sub-waves of the quantum system itself. A quantum system considered here can be any quantum system: a single microscopic particle, a composite quantum system such as an atom or a molecule, or a loose collection of a few quantum objects such as two independent photons. In the duality computer, the wave of the duality computer is split into several sub-waves and they pass through different routes, where different computing gate operations are performed. These sub-waves are then re-combined to interfere to give the computational results. The quantum computer, however, has only used the particle nature of quantum object. In a duality computer, it may be possible to find a marked item from an unsorted database using only a single query, and all NP-complete problems may have polynomial algorithms. Two proof-of-the-principle designs of the duality computer are presented: the giant molecule scheme and the nonlinear quantum optics scheme. We also propose thought experiment to check the related fundamental issues, the measurement efficiency of a partial wave function.
Quantum complexity of graph and algebraic problems
Energy Technology Data Exchange (ETDEWEB)
Doern, Sebastian
2008-02-04
This thesis is organized as follows: In Chapter 2 we give some basic notations, definitions and facts from linear algebra, graph theory, group theory and quantum computation. In Chapter 3 we describe three important methods for the construction of quantum algorithms. We present the quantum search algorithm by Grover, the quantum amplitude amplification and the quantum walk search technique by Magniez et al. These three tools are the basis for the development of our new quantum algorithms for graph and algebra problems. In Chapter 4 we present two tools for proving quantum query lower bounds. We present the quantum adversary method by Ambainis and the polynomial method introduced by Beals et al. The quantum adversary tool is very useful to prove good lower bounds for many graph and algebra problems. The part of the thesis containing the original results is organized in two parts. In the first part we consider the graph problems. In Chapter 5 we give a short summary of known quantum graph algorithms. In Chapter 6 to 8 we study the complexity of our new algorithms for matching problems, graph traversal and independent set problems on quantum computers. In the second part of our thesis we present new quantum algorithms for algebraic problems. In Chapter 9 to 10 we consider group testing problems and prove quantum complexity bounds for important problems from linear algebra. (orig.)
Cooperation, framing and political attitudes
DEFF Research Database (Denmark)
Fosgaard, Toke Reinholt; Hansen, Lars Gårn; Wengström, Erik Roland
This paper shows that political attitudes are linked to cooperative behavior in an incentivized experiment with a large sample randomly drawn from the Danish population. However, this relationship depends on the way the experiment is framed. In the standard game in which subjects give to a public...... good, contributions are the same regardless of political attitudes. In an economically equivalent version, in which subjects take from a public good, left-wingers cooperate significantly more than subjects in the middle or to the right of the political spectrum. Through simulation techniques we find...
Meta framing and polyphonic structures
DEFF Research Database (Denmark)
Pedersen, Karsten
2017-01-01
in various ways in BT’s 2012 coverage of a doping case involving Riis. In this article I investigate the way in which BT meta frames itself and its own actions in order to show and underline the seriousness with which BT treats sports journalism. The study is part of a recurring Danish project harvesting......The present case study deals with the Danish tabloid BT’s coverage of Cycling team owner Bjarne Riis’s possible knowledge of doping use in his cycling teams. BT sees itself as a sports paper and tries to signal that it takes sports coverage as seriously other kinds of news. We see that reflected...
Quantum mechanics as total physical theory
International Nuclear Information System (INIS)
Slavnov, D.A.
2002-01-01
It is shown that the principles of the total physical theory and conclusions of the standard quantum mechanics are not at such an antagonistic variance as it is usually accepted. The axioms, which make it possible to plot the renewed mathematical scheme of the quantum mechanics are formulated within the frames of the algebraic approach. The above scheme includes the standard mathematical apparatus of the quantum mechanics. Simultaneously there exists the mathematical object, which adequately describes the individual experiment. The examples of applying the proposed scheme is presented [ru
Problem Solving in Physics: Undergraduates' Framing, Procedures, and Decision Making
Modir, Bahar
In this dissertation I will start with the broad research question of what does problem solving in upper division physics look like? My focus in this study is on students' problem solving in physics theory courses. Some mathematical formalisms are common across all physics core courses such as using the process of separation of variables, doing Taylor series, or using the orthogonality properties of mathematical functions to set terms equal to zero. However, there are slight differences in their use of these mathematical formalisms across different courses, possibly because of how students map different physical systems to these processes. Thus, my first main research question aims to answer how students perform these recurring processes across upper division physics courses. I break this broad question into three particular research questions: What knowledge pieces do students use to make connections between physics and procedural math? How do students use their knowledge pieces coherently to provide reasoning strategies in estimation problems? How do students look ahead into the problem to read the information out of the physical scenario to align their use of math in physics? Building on the previous body of the literature, I will use the theory family of Knowledge in Pieces and provide evidence to expand this theoretical foundation. I will compare my study with previous studies and provide suggestions on how to generalize these theory expansions for future use. My experimental data mostly come from video-based classroom data. Students in groups of 2-4 students solve in-class problems in quantum mechanics and electromagnetic fields 1 courses collaboratively. In addition, I will analyze clinical interviews to demonstrate how a single case study student plays an epistemic game to estimate the total energy in a hurricane. My second research question is more focused on a particular instructional context. How do students frame problem solving in quantum mechanics? I
Memory cost of quantum contextuality
International Nuclear Information System (INIS)
Kleinmann, Matthias; Gühne, Otfried; Portillo, José R; Larsson, Jan-Åke; Cabello, Adán
2011-01-01
The simulation of quantum effects requires certain classical resources, and quantifying them is an important step to characterize the difference between quantum and classical physics. For a simulation of the phenomenon of state-independent quantum contextuality, we show that the minimum amount of memory used by the simulation is the critical resource. We derive optimal simulation strategies for important cases and prove that reproducing the results of sequential measurements on a two-qubit system requires more memory than the information-carrying capacity of the system. (paper)
Busch, Paul; Pellonpää, Juha-Pekka; Ylinen, Kari
2016-01-01
This is a book about the Hilbert space formulation of quantum mechanics and its measurement theory. It contains a synopsis of what became of the Mathematical Foundations of Quantum Mechanics since von Neumann’s classic treatise with this title. Fundamental non-classical features of quantum mechanics—indeterminacy and incompatibility of observables, unavoidable measurement disturbance, entanglement, nonlocality—are explicated and analysed using the tools of operational quantum theory. The book is divided into four parts: 1. Mathematics provides a systematic exposition of the Hilbert space and operator theoretic tools and relevant measure and integration theory leading to the Naimark and Stinespring dilation theorems; 2. Elements develops the basic concepts of quantum mechanics and measurement theory with a focus on the notion of approximate joint measurability; 3. Realisations offers in-depth studies of the fundamental observables of quantum mechanics and some of their measurement implementations; and 4....
Walls, D F
2007-01-01
Quantum Optics gives a comprehensive coverage of developments in quantum optics over the past years. In the early chapters the formalism of quantum optics is elucidated and the main techniques are introduced. These are applied in the later chapters to problems such as squeezed states of light, resonance fluorescence, laser theory, quantum theory of four-wave mixing, quantum non-demolition measurements, Bell's inequalities, and atom optics. Experimental results are used to illustrate the theory throughout. This yields the most comprehensive and up-to-date coverage of experiment and theory in quantum optics in any textbook. More than 40 exercises helps readers test their understanding and provide practice in quantitative problem solving.
International Nuclear Information System (INIS)
Markov, M.A.; West, P.C.
1984-01-01
This book discusses the state of the art of quantum gravity, quantum effects in cosmology, quantum black-hole physics, recent developments in supergravity, and quantum gauge theories. Topics considered include the problems of general relativity, pregeometry, complete cosmological theories, quantum fluctuations in cosmology and galaxy formation, a new inflationary universe scenario, grand unified phase transitions and the early Universe, the generalized second law of thermodynamics, vacuum polarization near black holes, the relativity of vacuum, black hole evaporations and their cosmological consequences, currents in supersymmetric theories, the Kaluza-Klein theories, gauge algebra and quantization, and twistor theory. This volume constitutes the proceedings of the Second Seminar on Quantum Gravity held in Moscow in 1981
Reconstruction of abstract quantum theory
International Nuclear Information System (INIS)
Drieschner, M.; Goernitz, T.; von Weizsaecker, C.F.
1988-01-01
Understanding quantum theory as a general theory of prediction, we reconstruct abstract quantum theory. Abstract means the general frame of quantum theory, without reference to a three-dimensional position space, to concepts like particle or field, or to special laws of dynamics. Reconstruction is the attempt to do this by formulating simple and plausible postulates on prediction in order to derive the basic concepts of quantum theory from them. Thereby no law of classical physics is presupposed which would then have to be quantized. We briefly discuss the relationship of theory and interpretation in physics and the fundamental role of time as a basic concept for physics. Then a number of assertions are given, formulated as succinctly as possible in order to make them easily quotable and comparable. The assertations are arranged in four groups: heuristic principles, verbal definitions of some terms, three basic postulates, and consequences. The three postulates of separable alternatives, indeterminism, and kinematics are the central points of this work. These brief assertions are commented upon, and their relationship with the interpretation of quantum theory is discussed. Also given are an outlook on the further development into concrete quantum theory and some philosophical reflections
Automating quantum experiment control
Stevens, Kelly E.; Amini, Jason M.; Doret, S. Charles; Mohler, Greg; Volin, Curtis; Harter, Alexa W.
2017-03-01
The field of quantum information processing is rapidly advancing. As the control of quantum systems approaches the level needed for useful computation, the physical hardware underlying the quantum systems is becoming increasingly complex. It is already becoming impractical to manually code control for the larger hardware implementations. In this chapter, we will employ an approach to the problem of system control that parallels compiler design for a classical computer. We will start with a candidate quantum computing technology, the surface electrode ion trap, and build a system instruction language which can be generated from a simple machine-independent programming language via compilation. We incorporate compile time generation of ion routing that separates the algorithm description from the physical geometry of the hardware. Extending this approach to automatic routing at run time allows for automated initialization of qubit number and placement and additionally allows for automated recovery after catastrophic events such as qubit loss. To show that these systems can handle real hardware, we present a simple demonstration system that routes two ions around a multi-zone ion trap and handles ion loss and ion placement. While we will mainly use examples from transport-based ion trap quantum computing, many of the issues and solutions are applicable to other architectures.
Framing Effects: Dynamics and Task Domains
Wang
1996-11-01
The author examines the mechanisms and dynamics of framing effects in risky choices across three distinct task domains (i.e., life-death, public property, and personal money). The choice outcomes of the problems presented in each of the three task domains had a binary structure of a sure thing vs a gamble of equal expected value; the outcomes differed in their framing conditions and the expected values, raging from 6000, 600, 60, to 6, numerically. It was hypothesized that subjects would become more risk seeking, if the sure outcome was below their aspiration level (the minimum requirement). As predicted, more subjects preferred the gamble when facing the life-death choice problems than facing the counterpart problems presented in the other two task domains. Subjects' risk preference varied categorically along the group size dimension in the life-death domain but changed more linearly over the expected value dimension in the monetary domain. Framing effects were observed in 7 of 13 pairs of problems, showing a positive frame-risk aversion and negative frame-risk seeking relationship. In addition, two types of framing effects were theoretically defined and empirically identified. A bidirectional framing effect involves a reversal in risk preference, and occurs when a decision maker's risk preference is ambiguous or weak. Four bidirectional effects were observed; in each case a majority of subjects preferred the sure outcome under a positive frame but the gamble under a negative frame. In contrast, a unidirectional framing effect refers to a preference shift due to the framing of choice outcomes: A majority of subjects preferred one choice outcome (either the sure thing or the gamble) under both framing conditions, with positive frame augmented the preference for the sure thing and negative frame augmented the preference for the gamble. These findings revealed some dynamic regularities of framing effects and posed implications for developing predictive and testable
Stapp, Henry P.
2011-01-01
Robert Griffiths has recently addressed, within the framework of a 'consistent quantum theory' that he has developed, the issue of whether, as is often claimed, quantum mechanics entails a need for faster-than-light transfers of information over long distances. He argues that the putative proofs of this property that involve hidden variables include in their premises some essentially classical-physics-type assumptions that are fundamentally incompatible with the precepts of quantum physics. O...
Grifoni, Milena
1997-01-01
In this thesis, ratchet systems operating in the quantum regime are investigated. Ratchet systems, also known as Brownian motors, are periodic systems presenting an intrinsic asymmetry which can be exploited to extract work out of unbiased forces. As a model for ratchet systems, we consider the motion of a particle in a one-dimensional periodic and asymmetric potential, interacting with a thermal environment, and subject to an unbiased driving force. In quantum ratchets, intrinsic quantum flu...
Quantum space and quantum completeness
Jurić, Tajron
2018-05-01
Motivated by the question whether quantum gravity can "smear out" the classical singularity we analyze a certain quantum space and its quantum-mechanical completeness. Classical singularity is understood as a geodesic incompleteness, while quantum completeness requires a unique unitary time evolution for test fields propagating on an underlying background. Here the crucial point is that quantum completeness renders the Hamiltonian (or spatial part of the wave operator) to be essentially self-adjoint in order to generate a unique time evolution. We examine a model of quantum space which consists of a noncommutative BTZ black hole probed by a test scalar field. We show that the quantum gravity (noncommutative) effect is to enlarge the domain of BTZ parameters for which the relevant wave operator is essentially self-adjoint. This means that the corresponding quantum space is quantum complete for a larger range of BTZ parameters rendering the conclusion that in the quantum space one observes the effect of "smearing out" the singularity.
International Nuclear Information System (INIS)
Basdevant, J.L.; Dalibard, J.; Joffre, M.
2008-01-01
All physics is quantum from elementary particles to stars and to the big-bang via semi-conductors and chemistry. This theory is very subtle and we are not able to explain it without the help of mathematic tools. This book presents the principles of quantum mechanics and describes its mathematical formalism (wave function, Schroedinger equation, quantum operators, spin, Hamiltonians, collisions,..). We find numerous applications in the fields of new technologies (maser, quantum computer, cryptography,..) and in astrophysics. A series of about 90 exercises with their answers is included. This book is based on a physics course at a graduate level. (A.C.)
International Nuclear Information System (INIS)
Rodgers, P.
1998-01-01
There is more to information than a string of ones and zeroes the ability of ''quantum bits'' to be in two states at the same time could revolutionize information technology. In the mid-1930s two influential but seemingly unrelated papers were published. In 1935 Einstein, Podolsky and Rosen proposed the famous EPR paradox that has come to symbolize the mysteries of quantum mechanics. Two years later, Alan Turing introduced the universal Turing machine in an enigmatically titled paper, On computable numbers, and laid the foundations of the computer industry one of the biggest industries in the world today. Although quantum physics is essential to understand the operation of transistors and other solid-state devices in computers, computation itself has remained a resolutely classical process. Indeed it seems only natural that computation and quantum theory should be kept as far apart as possible surely the uncertainty associated with quantum theory is anathema to the reliability expected from computers? Wrong. In 1985 David Deutsch introduced the universal quantum computer and showed that quantum theory can actually allow computers to do more rather than less. The ability of particles to be in a superposition of more than one quantum state naturally introduces a form of parallelism that can, in principle, perform some traditional computing tasks faster than is possible with classical computers. Moreover, quantum computers are capable of other tasks that are not conceivable with their classical counterparts. Similar breakthroughs in cryptography and communication followed. (author)
Energy Technology Data Exchange (ETDEWEB)
Rodgers, P
1998-03-01
There is more to information than a string of ones and zeroes the ability of ''quantum bits'' to be in two states at the same time could revolutionize information technology. In the mid-1930s two influential but seemingly unrelated papers were published. In 1935 Einstein, Podolsky and Rosen proposed the famous EPR paradox that has come to symbolize the mysteries of quantum mechanics. Two years later, Alan Turing introduced the universal Turing machine in an enigmatically titled paper, On computable numbers, and laid the foundations of the computer industry one of the biggest industries in the world today. Although quantum physics is essential to understand the operation of transistors and other solid-state devices in computers, computation itself has remained a resolutely classical process. Indeed it seems only natural that computation and quantum theory should be kept as far apart as possible surely the uncertainty associated with quantum theory is anathema to the reliability expected from computers? Wrong. In 1985 David Deutsch introduced the universal quantum computer and showed that quantum theory can actually allow computers to do more rather than less. The ability of particles to be in a superposition of more than one quantum state naturally introduces a form of parallelism that can, in principle, perform some traditional computing tasks faster than is possible with classical computers. Moreover, quantum computers are capable of other tasks that are not conceivable with their classical counterparts. Similar breakthroughs in cryptography and communication followed. (author)
International Nuclear Information System (INIS)
Khrennikov, Andrei; Klein, Moshe; Mor, Tal
2010-01-01
In number theory, a partition of a positive integer n is a way of writing n as a sum of positive integers. The number of partitions of n is given by the partition function p(n). Inspired by quantum information processing, we extend the concept of partitions in number theory as follows: for an integer n, we treat each partition as a basis state of a quantum system representing that number n, so that the Hilbert-space that corresponds to that integer n is of dimension p(n); the 'classical integer' n can thus be generalized into a (pure) quantum state ||ψ(n) > which is a superposition of the partitions of n, in the same way that a quantum bit (qubit) is a generalization of a classical bit. More generally, ρ(n) is a density matrix in that same Hilbert-space (a probability distribution over pure states). Inspired by the notion of quantum numbers in quantum theory (such as in Bohr's model of the atom), we then try to go beyond the partitions, by defining (via recursion) the notion of 'sub-partitions' in number theory. Combining the two notions mentioned above, sub-partitions and quantum integers, we finally provide an alternative definition of the quantum integers [the pure-state |ψ'(n)> and the mixed-state ρ'(n),] this time using the sub-partitions as the basis states instead of the partitions, for describing the quantum number that corresponds to the integer n.
International Nuclear Information System (INIS)
Deutsch, D.
1992-01-01
As computers become ever more complex, they inevitably become smaller. This leads to a need for components which are fabricated and operate on increasingly smaller size scales. Quantum theory is already taken into account in microelectronics design. This article explores how quantum theory will need to be incorporated into computers in future in order to give them their components functionality. Computation tasks which depend on quantum effects will become possible. Physicists may have to reconsider their perspective on computation in the light of understanding developed in connection with universal quantum computers. (UK)
Energy Technology Data Exchange (ETDEWEB)
Rodgers, P
1998-03-01
There is more to information than a string of ones and zeroes the ability of ''quantum bits'' to be in two states at the same time could revolutionize information technology. In the mid-1930s two influential but seemingly unrelated papers were published. In 1935 Einstein, Podolsky and Rosen proposed the famous EPR paradox that has come to symbolize the mysteries of quantum mechanics. Two years later, Alan Turing introduced the universal Turing machine in an enigmatically titled paper, On computable numbers, and laid the foundations of the computer industry one of the biggest industries in the world today. Although quantum physics is essential to understand the operation of transistors and other solid-state devices in computers, computation itself has remained a resolutely classical process. Indeed it seems only natural that computation and quantum theory should be kept as far apart as possible surely the uncertainty associated with quantum theory is anathema to the reliability expected from computers? Wrong. In 1985 David Deutsch introduced the universal quantum computer and showed that quantum theory can actually allow computers to do more rather than less. The ability of particles to be in a superposition of more than one quantum state naturally introduces a form of parallelism that can, in principle, perform some traditional computing tasks faster than is possible with classical computers. Moreover, quantum computers are capable of other tasks that are not conceivable with their classical counterparts. Similar breakthroughs in cryptography and communication followed. (author)
Tartakovskii, Alexander
2012-07-01
Part I. Nanostructure Design and Structural Properties of Epitaxially Grown Quantum Dots and Nanowires: 1. Growth of III/V semiconductor quantum dots C. Schneider, S. Hofling and A. Forchel; 2. Single semiconductor quantum dots in nanowires: growth, optics, and devices M. E. Reimer, N. Akopian, M. Barkelid, G. Bulgarini, R. Heeres, M. Hocevar, B. J. Witek, E. Bakkers and V. Zwiller; 3. Atomic scale analysis of self-assembled quantum dots by cross-sectional scanning tunneling microscopy and atom probe tomography J. G. Keizer and P. M. Koenraad; Part II. Manipulation of Individual Quantum States in Quantum Dots Using Optical Techniques: 4. Studies of the hole spin in self-assembled quantum dots using optical techniques B. D. Gerardot and R. J. Warburton; 5. Resonance fluorescence from a single quantum dot A. N. Vamivakas, C. Matthiesen, Y. Zhao, C.-Y. Lu and M. Atature; 6. Coherent control of quantum dot excitons using ultra-fast optical techniques A. J. Ramsay and A. M. Fox; 7. Optical probing of holes in quantum dot molecules: structure, symmetry, and spin M. F. Doty and J. I. Climente; Part III. Optical Properties of Quantum Dots in Photonic Cavities and Plasmon-Coupled Dots: 8. Deterministic light-matter coupling using single quantum dots P. Senellart; 9. Quantum dots in photonic crystal cavities A. Faraon, D. Englund, I. Fushman, A. Majumdar and J. Vukovic; 10. Photon statistics in quantum dot micropillar emission M. Asmann and M. Bayer; 11. Nanoplasmonics with colloidal quantum dots V. Temnov and U. Woggon; Part IV. Quantum Dot Nano-Laboratory: Magnetic Ions and Nuclear Spins in a Dot: 12. Dynamics and optical control of an individual Mn spin in a quantum dot L. Besombes, C. Le Gall, H. Boukari and H. Mariette; 13. Optical spectroscopy of InAs/GaAs quantum dots doped with a single Mn atom O. Krebs and A. Lemaitre; 14. Nuclear spin effects in quantum dot optics B. Urbaszek, B. Eble, T. Amand and X. Marie; Part V. Electron Transport in Quantum Dots Fabricated by
Quantum key distribution with two-segment quantum repeaters
Energy Technology Data Exchange (ETDEWEB)
Kampermann, Hermann; Abruzzo, Silvestre; Bruss, Dagmar [Theoretische Physik III, Heinrich-Heine-Universitaet Duesseldorf (Germany)
2014-07-01
Quantum repeaters represent one possible way to achieve long-distance quantum key distribution. One way of improving the repeater rate and decreasing the memory coherence time is the usage of multiplexing. Motivated by the experimental fact that long-range connections are practically demanding, we extend the analysis of the quantum repeater multiplexing protocol to the case of short-range connections. We derive formulas for the repeater rate and we show that short-range connections lead to most of the benefits of a full-range multiplexing protocol. A less demanding QKD-protocol without quantum memories was recently introduced by Lo et al. We generalize this measurement-device-independent quantum key Distribution protocol to the scenario where the repeater Station contains also heralded quantum memories. We assume either single-photon sources or weak coherent pulse sources plus decay states. We show that it is possible to significantly outperform the original proposal, even in presence of decoherence of the quantum memory. We give formulas in terms of device imperfections i.e., the quantum bit error rate and the repeater rate.
Modeling laser wakefield accelerators in a Lorentz boosted frame
Energy Technology Data Exchange (ETDEWEB)
Vay, J.-L.; Geddes, C.G.R.; Cormier-Michel, E.; Grotec, D. P.
2010-06-15
Modeling of laser-plasma wakefield accelerators in an optimal frame of reference is shown to produce orders of magnitude speed-up of calculations from first principles. Obtaining these speedups requires mitigation of a high-frequency instability that otherwise limits effectiveness in addition to solutions for handling data input and output in a relativistically boosted frame of reference. The observed high-frequency instability is mitigated using methods including an electromagnetic solver with tunable coefficients, its extension to accomodate Perfectly Matched Layers and Friedman's damping algorithms, as well as an efficient large bandwidth digital filter. It is shown that choosing the frame of the wake as the frame of reference allows for higher levels of filtering and damping than is possible in other frames for the same accuracy. Detailed testing also revealed serendipitously the existence of a singular time step at which the instability level is minimized, independently of numerical dispersion, thus indicating that the observed instability may not be due primarily to Numerical Cerenkov as has been conjectured. The techniques developed for Cerenkov mitigation prove nonetheless to be very efficient at controlling the instability. Using these techniques, agreement at the percentage level is demonstrated between simulations using different frames of reference, with speedups reaching two orders of magnitude for a 0.1 GeV class stages. The method then allows direct and efficient full-scale modeling of deeply depleted laser-plasma stages of 10 GeV-1 TeV for the first time, verifying the scaling of plasma accelerators to very high energies. Over 4, 5 and 6 orders of magnitude speedup is achieved for the modeling of 10 GeV, 100 GeV and 1 TeV class stages, respectively.
Modeling laser wakefield accelerators in a Lorentz boosted frame
International Nuclear Information System (INIS)
Vay, J.-L.; Geddes, C.G.R.; Cormier-Michel, E.; Grote, D.P.
2010-01-01
Modeling of laser-plasma wakefield accelerators in an optimal frame of reference (1) is shown to produce orders of magnitude speed-up of calculations from first principles. Obtaining these speedups requires mitigation of a high frequency instability that otherwise limits effectiveness in addition to solutions for handling data input and output in a relativistically boosted frame of reference. The observed high-frequency instability is mitigated using methods including an electromagnetic solver with tunable coefficients, its extension to accommodate Perfectly Matched Layers and Friedman's damping algorithms, as well as an efficient large bandwidth digital filter. It is shown that choosing the frame of the wake as the frame of reference allows for higher levels of filtering and damping than is possible in other frames for the same accuracy. Detailed testing also revealed serendipitously the existence of a singular time step at which the instability level is minimized, independently of numerical dispersion, thus indicating that the observed instability may not be due primarily to Numerical Cerenkov as has been conjectured. The techniques developed for Cerenkov mitigation prove nonetheless to be very efficient at controlling the instability. Using these techniques, agreement at the percentage level is demonstrated between simulations using different frames of reference, with speedups reaching two orders of magnitude for a 0.1 GeV class stages. The method then allows direct and efficient full-scale modeling of deeply depleted laser-plasma stages of 10 GeV-1 TeV for the first time, verifying the scaling of plasma accelerators to very high energies. Over 4, 5 and 6 orders of magnitude speedup is achieved for the modeling of 10 GeV, 100 GeV and 1 TeV class stages, respectively.
Frame by Frame II: A Filmography of the African American Image, 1978-1994.
Klotman, Phyllis R.; Gibson, Gloria J.
A reference guide on African American film professionals, this book is a companion volume to the earlier "Frame by Frame I." It focuses on giving credit to African Americans who have contributed their talents to a film industry that has scarcely recognized their contributions, building on the aforementioned "Frame by Frame I,"…
Message framing in social networking sites.
Kao, Danny Tengti; Chuang, Shih-Chieh; Wang, Sui-Min; Zhang, Lei
2013-10-01
Online social networking sites represent significant new opportunities for Internet advertisers. However, results based on the real world cannot be generalized to all virtual worlds. In this research, the moderating effects of need for cognition (NFC) and knowledge were applied to examine the impact of message framing on attitudes toward social networking sites. A total of 216 undergraduates participated in the study. Results reveal that for social networking sites, while high-NFC individuals form more favorable attitudes toward negatively framed messages than positively framed messages, low-NFC individuals form more favorable attitudes toward positively framed messages than negatively framed messages. In addition, low-knowledge individuals demonstrate more favorable attitudes toward negatively framed messages than positively framed messages; however, the framing effect does not differentially affect the attitudes of high-knowledge individuals. Furthermore, the framing effect does not differentially affect the attitudes of high-NFC individuals with high knowledge. In contrast, low-NFC individuals with low knowledge hold more favorable attitudes toward positively framed messages than negatively framed messages.
COMPARING FRAMES, FRAMING COMPARISONS: GREECE/EU FRAMES ON GENDER INEQUALITY IN POLITICS
Maloutas, Maro Pantelidou
2016-01-01
This article intends to present the main similarities and differences between Greece and the EU in respect to the framing of gender inequality in political decision making as a policy issue, based on the ways that the problem is diagnosed. It also aims at the formulation of a hypothesis which argues that beyond the above similarities and differences, which may tint in a different colour measures and policies showing one case more gender sensitive or more «traditional» than the other, there ex...
Frames, operator representations, and open problems
DEFF Research Database (Denmark)
Christensen, Ole; Hasannasab, Marzieh
2018-01-01
, a topic that has recently attracted considerably interest within harmonic analysis. The goal of the paper is twofold, namely, that experts in operator theory will explore the potential of frames, and that frame theory will benefit from insight provided by the operator theory community.......A frame in a Hilbert space H is a countable collection of elements in H that allows each f Ïµ H to be expanded as an (infinite) linear combination of the frame elements. Frames generalize the wellknown orthonormal bases, but provide much more exibility and can often be constructed with properties...... that are not possible for orthonormal bases. We will present the basic facts in frame theory with focus on their operator theoretical characterizations and discuss open problems concerning representations of frames in terms of iterations of a fixed operator. These problems come up in the context of dynamical sampling...
Technological Frame Incongruence, Diffusion, and Noncompliance
Sobreperez, Polly
The technological frames of reference strand of social shaping of technology theory is used to overlay the issues arising from a case study looking at noncompliance with information systems. A recent review of the theory suggests that although frame content is often addressed, frame structure, the process of framing, and the characteristics and outcomes of frames are largely overlooked. This paper attempts to address this shortfall by applying the indicators identified by case study research to the frames of different groups and using them to highlight differing perceptions and attitudes. In this way, the author suggests that issues surrounding noncompliance should not be dismissed as resistance but instead should be further studied by managers and developers, leading to accommodation of differing views. Further examination of frame incongruence reveals dependence on inefficient or ineffective organizational situations and thus these indicators can be useful in future studies to identify and address procedural, acceptance and cultural issues leading to acts of noncompliance.
Towards a poetics of the cinematographic frame
Directory of Open Access Journals (Sweden)
Des O'Rawe
2011-05-01
Full Text Available In delineating a poetics of the cinematographic frame, this essay presents a typology of framing styles, and demonstrates ways in which filmmakers use the frame as an expressive resource—and ways in which the frame uses them. The examples discussed are modernist in orientation, and each has a particular association with a city—its history, architecture, and cultural character. Although it is common practice to refer to various—especially, modernist—framing situations as instances of deframing, the essay also enquires into the problematic nature of this term, suggesting alternative visual and cinematographic contexts more amenable to the deconstructive implications of this term. As the boundaries between cinema and the other arts continue to converge and relations between frame, image, and screen become more complex, this essay offers a reassessment of some first principles of film language, especially the aesthetic integrity of the cinematographic frame.
Characterization of Oblique Dual Frame Pairs
Directory of Open Access Journals (Sweden)
Christensen Ole
2006-01-01
Full Text Available Given a frame for a subspace of a Hilbert space , we consider all possible families of oblique dual frame vectors on an appropriately chosen subspace . In place of the standard description, which involves computing the pseudoinverse of the frame operator, we develop an alternative characterization which in some cases can be computationally more efficient. We first treat the case of a general frame on an arbitrary Hilbert space, and then specialize the results to shift-invariant frames with multiple generators. In particular, we present explicit versions of our general conditions for the case of shift-invariant spaces with a single generator. The theory is also adapted to the standard frame setting in which the original and dual frames are defined on the same space.
"Think" versus "feel" framing effects in persuasion.
Mayer, Nicole D; Tormala, Zakary L
2010-04-01
Three studies explored think ("I think . . . ") versus feel ("I feel . . . ") message framing effects on persuasion.The authors propose a matching hypothesis, suggesting that think framing will be more persuasive when the target attitude or message recipient is cognitively oriented, whereas feel framing will be more persuasive when the target attitude or message recipient is affectively oriented. Study 1 presented cognitively and affectively oriented individuals with a think- or feel-framed message. Study 2 primed cognitive or affective orientation and then presented a think- or feel-framed message. Study 3 presented male and female participants with an advertisement containing think- or feel-framed arguments. Results indicated that think (feel) framing was more persuasive when the target attitude or recipient was cognitively (affectively) oriented. Moreover, Study 2 demonstrated that this matching effect was mediated by processing fluency. Theoretical and practical implications are discussed.
Analisis Framing dalam Riset Public Relations
Directory of Open Access Journals (Sweden)
NARAYANA MAHENDRA PRASTYA
2016-12-01
Full Text Available This paper aims to give description about how to use frame analysis in Public Relations (PR research. The author use two framing models: Entman and Pan & Kosicki. The object is organization official statement about particular issue. Frame analysis method rarely used in Public Relations research. This methods commonly use in journalism study, to analyse the news in media. Meanwhile, the key word of framing is the social construction of reality. Organization can make social construction of realty in their official statement. In acacemic term, frame analysis in PR research is useful to know how organization positioned themselves in particular situation. Other benefit is use to evaluat whether the organization frame is conformable with the public opinion or agenda setting media or not. In practical term, frame analysis give benefit for PR practitioner to create the message that can be undserstood by public, also give positive image for organization.
Wave propagation properties of frame structures. Formulation for three-dimensional frame structures
International Nuclear Information System (INIS)
Nishida, Akemi
2006-01-01
Since it is generally difficult to predict the occurrence of natural disasters such as earth-quakes, a performance management system that constantly maintains the safety and functionality of structures is required, particularly for critical structures like nuclear power plants. In order to realize such a system, it is becoming important to carry out detailed modeling procedures and analyses to better understand actual phenomena. The aim of our research is to determine the dynamic behavior - especially the wave propagation phenomena - of piping systems in nuclear power plants, which are complicated assemblages of parts. The spectral element method is adopted in this study, and the formulation considering a shear deformation independently for a frame element is described. The Timoshenko beam theory is introduced for the purpose of this formulation. The validity of the presented element will be shown through comparisons with the conventional beam element. (author)
Quantum correlator outside a Schwarzschild black hole
Directory of Open Access Journals (Sweden)
Claudia Buss
2018-01-01
Full Text Available We calculate the quantum correlator in Schwarzschild black hole space–time. We perform the calculation for a scalar field in three different quantum states: Boulware, Unruh and Hartle–Hawking, and for points along a timelike circular geodesic. The results show that the correlator presents a global fourfold singularity structure, which is state-independent. Our results also show the different correlations in the three different quantum states arising in-between the singularities.
Quantum rewinding via phase estimation
Tabia, Gelo Noel
2015-03-01
In cryptography, the notion of a zero-knowledge proof was introduced by Goldwasser, Micali, and Rackoff. An interactive proof system is said to be zero-knowledge if any verifier interacting with an honest prover learns nothing beyond the validity of the statement being proven. With recent advances in quantum information technologies, it has become interesting to ask if classical zero-knowledge proof systems remain secure against adversaries with quantum computers. The standard approach to show the zero-knowledge property involves constructing a simulator for a malicious verifier that can be rewinded to a previous step when the simulation fails. In the quantum setting, the simulator can be described by a quantum circuit that takes an arbitrary quantum state as auxiliary input but rewinding becomes a nontrivial issue. Watrous proposed a quantum rewinding technique in the case where the simulation's success probability is independent of the auxiliary input. Here I present a more general quantum rewinding scheme that employs the quantum phase estimation algorithm. This work was funded by institutional research grant IUT2-1 from the Estonian Research Council and by the European Union through the European Regional Development Fund.
Quantum indistinguishability in chemical reactions.
Fisher, Matthew P A; Radzihovsky, Leo
2018-05-15
Quantum indistinguishability plays a crucial role in many low-energy physical phenomena, from quantum fluids to molecular spectroscopy. It is, however, typically ignored in most high-temperature processes, particularly for ionic coordinates, implicitly assumed to be distinguishable, incoherent, and thus well approximated classically. We explore enzymatic chemical reactions involving small symmetric molecules and argue that in many situations a full quantum treatment of collective nuclear degrees of freedom is essential. Supported by several physical arguments, we conjecture a "quantum dynamical selection" (QDS) rule for small symmetric molecules that precludes chemical processes that involve direct transitions from orbitally nonsymmetric molecular states. As we propose and discuss, the implications of the QDS rule include ( i ) a differential chemical reactivity of para- and orthohydrogen, ( ii ) a mechanism for inducing intermolecular quantum entanglement of nuclear spins, ( iii ) a mass-independent isotope fractionation mechanism, ( iv ) an explanation of the enhanced chemical activity of "reactive oxygen species", ( v ) illuminating the importance of ortho-water molecules in modulating the quantum dynamics of liquid water, and ( vi ) providing the critical quantum-to-biochemical linkage in the nuclear spin model of the (putative) quantum brain, among others.
Quantum group and quantum symmetry
International Nuclear Information System (INIS)
Chang Zhe.
1994-05-01
This is a self-contained review on the theory of quantum group and its applications to modern physics. A brief introduction is given to the Yang-Baxter equation in integrable quantum field theory and lattice statistical physics. The quantum group is primarily introduced as a systematic method for solving the Yang-Baxter equation. Quantum group theory is presented within the framework of quantum double through quantizing Lie bi-algebra. Both the highest weight and the cyclic representations are investigated for the quantum group and emphasis is laid on the new features of representations for q being a root of unity. Quantum symmetries are explored in selected topics of modern physics. For a Hamiltonian system the quantum symmetry is an enlarged symmetry that maintains invariance of equations of motion and allows a deformation of the Hamiltonian and symplectic form. The configuration space of the integrable lattice model is analyzed in terms of the representation theory of quantum group. By means of constructing the Young operators of quantum group, the Schroedinger equation of the model is transformed to be a set of coupled linear equations that can be solved by the standard method. Quantum symmetry of the minimal model and the WZNW model in conformal field theory is a hidden symmetry expressed in terms of screened vertex operators, and has a deep interplay with the Virasoro algebra. In quantum group approach a complete description for vibrating and rotating diatomic molecules is given. The exact selection rules and wave functions are obtained. The Taylor expansion of the analytic formulas of the approach reproduces the famous Dunham expansion. (author). 133 refs, 20 figs
Approximately dual frames in Hilbert spaces and applications to Gabor frames
Christensen, Ole; Laugesen, Richard S.
2011-01-01
Approximately dual frames are studied in the Hilbert space setting. Approximate duals are easier to construct than classical dual frames, and can be tailored to yield almost perfect reconstruction. Bounds on the deviation from perfect reconstruction are obtained for approximately dual frames constructed via perturbation theory. An alternative bound is derived for the rich class of Gabor frames, by using the Walnut representation of the frame operator to estimate the deviation from equality in...