Nonlocal advantage of quantum coherence under relativistic frame

2018 ◽  
Vol 32 (31) ◽  
pp. 1850377 ◽  
Author(s):  
Long-Fei Wang ◽  
Ming-Ming Du ◽  
Wen-Yang Sun ◽  
Dong Wang ◽  
Liu Ye
Keyword(s):  
Sudden Death ◽  
Quantum Coherence ◽  
Quantum Discord ◽  
Thermal Noise ◽  
Unruh Effect ◽  
Qubit System ◽  
Bell Nonlocality ◽  
Better Than

In this paper, we investigate the influence of the Unruh effect on the achievement of the nonlocal advantage of quantum coherence for a two-qubit system under a relativistic frame. The results show that with the increase of acceleration, it is difficult to realize the nonlocal advantage of quantum coherence and when the acceleration exceeds a certain value, nonlocal advantage of quantum coherence cannot be realized. In addition, we explore the dynamics of Bell nonlocality, steering, quantum coherence, entanglement and quantum discord (QD) under Unruh thermal noise. It is shown that nonlocal advantage of quantum coherence, Bell nonlocality, steering and entanglement experience “sudden death” for a finite acceleration, while quantum coherence and QD vanish only in the limit of an infinite acceleration. We also find that not all nonlocal states can achieve the nonlocal advantage of quantum coherence. It is also demonstrated that the robustness of Bell nonlocality is better than nonlocal advantage of quantum coherence under the influence of the Unruh noise.

scholarly journals Quantum coherence versus nonclassical correlations in optomechanics

2019 ◽  
Vol 33 (29) ◽  
pp. 1950343
Author(s):  
Y. Lahlou ◽  
M. Amazioug ◽  
J. El Qars ◽  
N. Habiballah ◽  
M. Daoud ◽  
...  
Keyword(s):  
Quantum Mechanics ◽  
Quantum Coherence ◽  
Quantum Discord ◽  
Thermal Noise ◽  
Superposition Principle ◽  
Quantum Correlations ◽  
Entanglement Of Formation ◽  
Mechanical Subsystem ◽  
Optomechanical Coupling ◽  
Gaussian Quantum Discord

Coherence arises from the superposition principle, where it plays a central role in quantum mechanics. In Phys. Rev. Lett. 114, 210401 (2015), it has been shown that the freezing phenomenon of quantum correlations beyond entanglement is intimately related to the freezing of quantum coherence (QC). In this paper, we compare the behavior of entanglement and quantum discord with quantum coherence in two different subsystems (optical and mechanical). We use respectively the entanglement of formation (EoF) and the Gaussian quantum discord (GQD) to quantify entanglement and quantum discord. Under thermal noise and optomechanical coupling effects, we show that EoF, GQD and QC behave in the same way. Remarkably, when entanglement vanishes, GQD and QC remain almost unaffected by thermal noise, keeping nonzero values even for high-temperature, which is in concordance with Phys. Rev. Lett. 114, 210401 (2015). Also, we find that the coherence associated with the optical subsystem is more robust — against thermal noise — than those of the mechanical subsystem. Our results confirm that optomechanical cavities constitute a powerful resource of QC.

QUANTUM CORRELATIONS AT FINITE TEMPERATURE

2012 ◽  
Vol 10 (02) ◽  
pp. 1250027 ◽  
Author(s):  
LIANG QIU
Keyword(s):  
Sudden Death ◽  
Finite Temperature ◽  
Quantum Discord ◽  
Quantum Correlations ◽  
Entangled States ◽  
Dense Coding ◽  
Geometric Measure ◽  
Bell Nonlocality ◽  
Maximally Entangled States

We show that, under the influence of finite temperature reservoirs, for a board class of states, Bell nonlocality always endures sudden death. Furthermore, for two states evolved from two different maximally entangled states, the larger the concurrence and quantum discord, the better the resource for dense coding. However, the more usefulness of a state for teleportation could not be owed to the larger negativity and geometric measure of discord.

Protecting quantum coherence in an open system under non-inertial frames

2017 ◽  
Vol 31 (35) ◽  
pp. 1750336
Author(s):  
Long-Fei Wang ◽  
Ming-Ming Du ◽  
Liu Ye
Keyword(s):  
Open System ◽  
Significant Interaction ◽  
Quantum Coherence ◽  
Weak Measurement ◽  
Entangled State ◽  
Unruh Effect ◽  
Amplitude Damping ◽  
Inertial Frames ◽  
Weak Measurement And Reversal

In this paper, we explore the dynamics and protection of quantum coherence in an open system under non-inertial frames by weak measurement and reversal, and design four strategies to protect the quantum coherence of an initial two-qubit entangled state, when the systems suffer from amplitude damping (AD) channel and one subsystem is under non-inertial frames. In practice, there is no strict inertial frames, decoherence and degradation of the quantum coherence caused by the Unruh effect form acceleration will have a significant interaction, therefore it is important to find some means to protect quantum coherence under non-inertial frames.

Robustness of quantum discord to sudden death

2009 ◽  
Vol 80 (2) ◽  
Author(s):  
T. Werlang ◽  
S. Souza ◽  
F. F. Fanchini ◽  
C. J. Villas Boas
Keyword(s):  
Sudden Death ◽  
Quantum Discord

Effectiveness of Non-Markovian Methods for Quantum Discord Dynamics of Non-coupled Two-Qubit System

2018 ◽  
Vol 70 (3) ◽  
pp. 268 ◽  
Author(s):  
Yong-Gang Huang ◽  
Xiao-Yun Wang ◽  
Xue-Xian Yang ◽  
Ke Deng ◽  
Jin-Zhang Peng ◽  
...  
Keyword(s):  
Quantum Discord ◽  
Qubit System

Quantum correlations and coherence dynamics in qutrit–qutrit systems under mixed classical environmental noises

2017 ◽  
Vol 15 (06) ◽  
pp. 1750047 ◽  
Author(s):  
Tsamouo Tsokeng Arthur ◽  
Tchoffo Martin ◽  
Lukong Cornelius Fai
Keyword(s):  
Sudden Death ◽  
Quantum Discord ◽  
Quantum Correlations ◽  
Collective Effects ◽  
Markovian Environment ◽  
Dynamic Noise ◽  
Long Time ◽  
Noise Models ◽  
Markovian Regime ◽  
Static Noise

We investigate the dynamics of entanglement, quantum discord (QD) and state coherence in a bipartite and noninteracting spin-qutrits system under mixed classical noises. Specifically, the collective effects of static noise (SN) and random telegraphic noise (RTN) each being coupled with a marginal system, are analyzed. While the static noise models a non-Markovian environment, the dynamic noise can model both a Markovian or a non-Markovian environment, and both dynamics are studied. We show that quantum correlations and coherence may survive the noise degrading effects at sufficiently long time when the Markovian regime of the RTN is considered. Meanwhile, the opposite is found in the non-Markovian regime, wherein the nonmonotonic dynamics of quantum features avoid sudden death phenomena. However, the static noise is more fatal to the survival of quantum correlations and quantum state coherence as compared to the RTN.

Tripartite states Bell-nonlocality sudden death in a spin environment with multisite interaction

2011 ◽  
Vol 20 (8) ◽  
pp. 080301 ◽  
Author(s):  
Li-Jun Xie ◽  
Deng-Yu Zhang ◽  
Xin-Wen Wang ◽  
Xiao-Gui Zhan ◽  
Shi-Qing Tang ◽  
...  
Keyword(s):  
Sudden Death ◽  
Bell Nonlocality

scholarly journals Quasi-probability information in a coupled two-qubit system interacting non-linearly with a coherent cavity under intrinsic decoherence

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Abdel-Baset A. Mohamed ◽  
Hichem Eleuch
Keyword(s):  
Phase Space ◽  
Quantum Coherence ◽  
Coupling Constants ◽  
Light Quantum ◽  
Wehrl Entropy ◽  
Intrinsic Decoherence ◽  
Highly Sensitive ◽  
Qubit System ◽  
Probability Information ◽  
Q Function

AbstractWe explore the phase space quantum effects, quantum coherence and non-classicality, for two coupled identical qubits with intrinsic decoherence. The two qubits are in a nonlinear interaction with a quantum field via an intensity-dependent coupling. We investigate the non-classicality via the Wigner functions. We also study the phase space information and the quantum coherence via the Q-function, Wehrl density, and Wehrl entropy. It is found that the robustness of the non-classicality for the superposition of coherent states, is highly sensitive to the coupling constants. The phase space quantum information and the matter-light quantum coherence can be controlled by the two-qubit coupling, initial cavity-field and the intrinsic decoherence.

Frozen Quantum Coherence for a Central Two-Qubit System in a Spin-Chain Environment

2018 ◽  
Vol 35 (8) ◽  
pp. 080301
Author(s):  
Yang Yang ◽  
An-Min Wang ◽  
Lian-Zhen Cao ◽  
Jia-Qiang Zhao ◽  
Huai-Xin Lu
Keyword(s):  
Spin Chain ◽  
Quantum Coherence ◽  
Qubit System
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