Conference

Displaying 3013 - 3024 of 4905

Entanglement Resonances

June 26, 2012

PIRSA:12060055
Finite Size Detectors in RQI

Antony Lee University of Nottingham

June 26, 2012

PIRSA:12060054
Quantum Time-Like Curves: From Thought Experiment to Real Experiment

June 26, 2012

PIRSA:12060053
Localised Detection of the Unruh Effect

June 26, 2012

PIRSA:12060052
Localised Detection of Relativistic Quantum Fields in Non-Inertial Frames

Andrzej Dragan University of Warsaw

June 26, 2012

PIRSA:12060040
Quantum Interference of “Clocks”

Časlav Brukner Institute for Quantum Optics and Quantum Information (IQOQI) - Vienna

June 26, 2012

PIRSA:12060050
Nonlocality, Entanglement Witnesses and Supra-Correlations

Paul Alsing United States Air Force Research Laboratory

June 25, 2012

PIRSA:12060076
Towards Universal Quantum Computation Out of Relativistic Motion of Particle Detectors

David Aasen California Institute of Technology

June 25, 2012

PIRSA:12060049
Boundary Effects on Quantum Entanglement and its Dynamics in a Detector-Field System

June 25, 2012

PIRSA:12060074
Tripartite Entanglement, Svetlichny Inequalities, and Non-inertial Observers

Robert Mann University of Waterloo

June 25, 2012

PIRSA:12060042
Geometric Discord in Non-Inertial Frames

Eric Brown University of Chicago

June 25, 2012

PIRSA:12060058
Quantum Teleportation from Alice to Rob in Vacuum

Shih-Yuin Lin National Changhua University of Education

June 25, 2012

PIRSA:12060047

Entanglement Resonances

June 26, 2012

PIRSA:12060055

We investigate entanglement creation between modes of a quantum field contained within a cavity which undergoes noninertial motion. We find that, in the the low acceleration regime, or equivalently in the small cavity regime, entanglement can be created from initially separable states and it can be linearly increased by repeating travel scenarios. We are able to fin analytically how all the parameter involved affect the entanglement. We suggest that this can be of interest when looking for experimental veriications of predictions within the field of relativistic quantum information.
Finite Size Detectors in RQI

Antony Lee University of Nottingham

June 26, 2012

PIRSA:12060054
Quantum Time-Like Curves: From Thought Experiment to Real Experiment

June 26, 2012

PIRSA:12060053

Thought experiments involving quantum mechanics in the presence of closed time-like curves (CTCs) seem to have little to do with reality. However, even particles that traverse the CTC passively and without interactions can lead to highly non-trivial effects, such as the maximal violation of the uncertainty principle. Moreover, these effects may carry over to curved space-times without CTCs, presenting novel opportunities for testing non-standard physics in the relativistic regime.
Localised Detection of the Unruh Effect

June 26, 2012

PIRSA:12060052

I will discuss a new proposal with the potential to experimentally probe the validity of Rindler quantisation from the recent completely localized framework of non-inertial projective detectors of quantum fields.
Localised Detection of Relativistic Quantum Fields in Non-Inertial Frames

Andrzej Dragan University of Warsaw

June 26, 2012

PIRSA:12060040

We introduce a novel approach to measurements in QFT in non-inertial frames. A simple, localised, analytical model of state detection allows us to study all the standard questions of RQI and yielding simple answers with a clear physical interpretation. We apply the model to investigate extraction of the entanglement from the vacuum, completely characterize entangled state of two localised inertial wave-packets in the accelerating frame and study the entanglement degradation as a function of the proper acceleration of the detector.
Quantum Interference of “Clocks”

Časlav Brukner Institute for Quantum Optics and Quantum Information (IQOQI) - Vienna

June 26, 2012

PIRSA:12060050

Experimental tests of general relativity performed so far involve systems that can be effectively described by classical physics. On the other hand, observed gravity effects on quantum systems do not go beyond the Newtonian limit of the theory. In light of the conceptual differences between general relativity and quantum mechanics, as well as those of finding a unified theoretical framework for the two theories, it is of particular interest to look for feasible experiments that can only be explained if both theories apply. We propose testing general relativistic time dilation with a single “clock” in a superposition of two paths in space-time, along which time flows at different rates. We show that the interference visibility in such an experiment will decrease to the extent to which the path information becomes available from reading out the time from the “clock”. This effect would provide the first test of the genuine general relativistic notion of time in quantum mechanics. We consider implementation of the “clock” in evolving internal degrees of freedom of a massive particle and, alternatively, in the external degree of a photon and analyze the feasibility of the experiment.
Nonlocality, Entanglement Witnesses and Supra-Correlations

Paul Alsing United States Air Force Research Laboratory

June 25, 2012

PIRSA:12060076

While entanglement is believed to underlie the power of quantum computation and communication, it is not generally well understood for multipartite systems. Recently, it has been appreciated that there exists proper no-signaling probability distributions derivable from operators that do not represent valid quantum states. Such systems exhibit supra-correlations that are stronger than allowed by quantum mechanics, but less than the algebraically allowed maximum in Bell-inequalities (in the bipartite case). Some of these probability distributions are derivable from an entanglement witness W, which is a non-positive Hermitian operator constructed such that its expectation value with a separable quantum state (positive density matrix) rho_sep is non-negative (so that Tr[W rho]< 0 indicates entanglement in quantum state rho). In the bipartite case, it is known that by a modification of the local no-signaling measurements by spacelike separated parties A and B, the supra-correlations exhibited by any W can be modeled as derivable from a physically realizable quantum state ρ. However, this result does not generalize to the n-partite case for n>2. Supra-correlations can also be exhibited in 2- and 3-qubit systems by explicitly constructing "states" O (not necessarily positive quantum states) that exhibit PR correlations for a fixed, but arbitrary number, of measurements available to each party. In this paper we examine the structure of "states" that exhibit supra-correlations. In addition, we examine the affect upon the distribution of the correlations amongst the parties involved when constraints of positivity and purity are imposed. We investigate circumstances in which such "states" do and do not represent valid quantum states.
Towards Universal Quantum Computation Out of Relativistic Motion of Particle Detectors

David Aasen California Institute of Technology

June 25, 2012

PIRSA:12060049
Boundary Effects on Quantum Entanglement and its Dynamics in a Detector-Field System

June 25, 2012

PIRSA:12060074

We analyze an exactly solvable model consisting of an inertial Unruh-DeWitt detector which interacts linearly with a massless quantum field in Minkowski spacetime with a perfectly reflecting flat plane boundary. This model is related to proposed mirror-field superposition and relevant experiments in macroscopic quantum phenomena, as well as atomic fluctuation forces near a conducting surface. Firstly a coupled set of equations for the detector’s and the field’s Heisenberg operators are derived. After coarse graining the field, the dynamics of the detector’s internal degreeof freedom is described by a quantum Langevin equation, where the dissipation and noise kernels respectively correspond to the retarded Green’s functions and Hadamard elementary functions of the free quantum field in half space. We use the linear entropy as measures of entanglement between the detector and the quantum field under mirror reflection, then solve the early-time detector-fieldentanglement dynamics. At late times when the combined system is in a stationary state, we obtain exact expressions for the detector’s covariance matrix and show that the detector-field entanglement decreases for smaller separation between the detector and the mirror.We explain the behavior of detector-field entanglement qualitatively with the help of a detector’s mirror image, compare them with the case of two real detectors and explain the differences.
Tripartite Entanglement, Svetlichny Inequalities, and Non-inertial Observers

Robert Mann University of Waterloo

June 25, 2012

PIRSA:12060042

I discuss the behaviour of bipartite and tripartite non-locality between fermionic entangled states shared by observers, one of whom uniformly accelerates. Although fermionic entanglement persists for arbitrarily large acceleration, the Bell/CHSH inequalities cannot be violated for sufficiently large but finite acceleration. However the Svetlichny inequality, which is a measure of genuine tripartite non-locality, can be violated for any finite value of the acceleration.
Geometric Discord in Non-Inertial Frames

Eric Brown University of Chicago

June 25, 2012

PIRSA:12060058

I review the recent work performed on computing the geometric discord in non-inertial frames. We consider the well-known case of an inertially maximally entangled state shared by inertial Alice and non-inertial Robb. It is found that for high accelerations the geometric discord decays to a negligible amount; this is in stark contrast to the entropic definition of quantum discord which asymptotes to a finite value in the same limit. Such a result has two different implications: the first being that usable quantum correlations are more limited in this regime than previously thought and the second being that geometric discord may not be a sufficient measure of quantum correlations. I will discuss both of these perspectives.
Quantum Teleportation from Alice to Rob in Vacuum

Shih-Yuin Lin National Changhua University of Education

June 25, 2012

PIRSA:12060047

We consider quantum teleportation of continuous variables in a relativistic system with the Unruh-DeWitt detectorscoupled to a common quantum field initially in the Minkowski vacuum. An unknown coherent state of an Unruh-DeWitt detector is teleported from one inertial agent (Alice) to an almost uniformly accelerated agent (Rob), using a detector pair initially entangled and shared by these two agents. Results for the averaged physical fidelity of quantum teleportation will be discussed.

Title	Speaker(s)	Date	Talk Type	Info link
Entanglement Resonances		2012-06-26	Conference	View details
Finite Size Detectors in RQI	Antony Lee	2012-06-26	Conference	View details
Quantum Time-Like Curves: From Thought Experiment to Real Experiment		2012-06-26	Conference	View details
Localised Detection of the Unruh Effect		2012-06-26	Conference	View details
Localised Detection of Relativistic Quantum Fields in Non-Inertial Frames	Andrzej Dragan	2012-06-26	Conference	View details
Quantum Interference of “Clocks”	Časlav Brukner	2012-06-26	Conference	View details
Nonlocality, Entanglement Witnesses and Supra-Correlations	Paul Alsing	2012-06-25	Conference	View details
Towards Universal Quantum Computation Out of Relativistic Motion of Particle Detectors	David Aasen	2012-06-25	Conference	View details
Boundary Effects on Quantum Entanglement and its Dynamics in a Detector-Field System		2012-06-25	Conference	View details
Tripartite Entanglement, Svetlichny Inequalities, and Non-inertial Observers	Robert Mann	2012-06-25	Conference	View details
Geometric Discord in Non-Inertial Frames	Eric Brown	2012-06-25	Conference	View details
Quantum Teleportation from Alice to Rob in Vacuum	Shih-Yuin Lin	2012-06-25	Conference	View details

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Format results

Entanglement Resonances

Finite Size Detectors in RQI

Quantum Time-Like Curves: From Thought Experiment to Real Experiment

Localised Detection of the Unruh Effect

Localised Detection of Relativistic Quantum Fields in Non-Inertial Frames

Quantum Interference of “Clocks”

Nonlocality, Entanglement Witnesses and Supra-Correlations

Towards Universal Quantum Computation Out of Relativistic Motion of Particle Detectors

Boundary Effects on Quantum Entanglement and its Dynamics in a Detector-Field System

Tripartite Entanglement, Svetlichny Inequalities, and Non-inertial Observers

Geometric Discord in Non-Inertial Frames

Quantum Teleportation from Alice to Rob in Vacuum

Entanglement Resonances

Finite Size Detectors in RQI

Quantum Time-Like Curves: From Thought Experiment to Real Experiment

Localised Detection of the Unruh Effect

Localised Detection of Relativistic Quantum Fields in Non-Inertial Frames

Quantum Interference of “Clocks”

Nonlocality, Entanglement Witnesses and Supra-Correlations

Towards Universal Quantum Computation Out of Relativistic Motion of Particle Detectors

Boundary Effects on Quantum Entanglement and its Dynamics in a Detector-Field System

Tripartite Entanglement, Svetlichny Inequalities, and Non-inertial Observers

Geometric Discord in Non-Inertial Frames

Quantum Teleportation from Alice to Rob in Vacuum