Quantum Discord Behaviors in Two Qubits Spin Squeezing Model with Intrinsic Decoherence

2015 ◽  
Vol 55 (5) ◽  
pp. 2588-2597 ◽  
Author(s):  
Yang Guo-Hui ◽  
Zhang Bing-Bing
Keyword(s):  
Quantum Discord ◽  
Spin Squeezing ◽  
Intrinsic Decoherence ◽  
Spin Squeezing Model

scholarly journals Effects of phase shift on bipartite and multipartite correlations of a spin chain under dephasing

Open Physics ◽  
2015 ◽  
Vol 13 (1) ◽  
Author(s):  
Ai-Xi Chen ◽  
Jian-Song Zhang
Keyword(s):  
Steady State ◽  
Phase Shift ◽  
Analytical Solution ◽  
Spin Chain ◽  
Quantum Discord ◽  
Present Model ◽  
Spin Squeezing ◽  
Heisenberg Chain ◽  
Initial Correlations ◽  
Long Time

AbstractWe investigate the effects of phase shift on entanglement, quantum discord, geometric discord, and spinsqueezing of a Heisenberg chain under dephasing. An analytical solution of the present model is obtained. Our results show that the initial correlations of the spin chain could be partially stored for a long time in the presence of dephasing and the amount of steady state correlations can be adjusted via phase shift. Particularly, we find the effects of phase shift on quantum discord and geometric discord are not always the same, i.e., the increase of geometric discord does not always imply the increase of quantum discord. Then, we calculate the spin-squeezing of the spin chain and find that spin-squeezing first increases with time and then reaches a plateau. The amount of spin-squeezing can be controlled via phase shift.

Robustness of Quantum Correlations in Entangled Two su(2) Systems Non-mutually Interacting with su(1, 1) System under Intrinsic Decoherence

2018 ◽  
Vol 25 (03) ◽  
pp. 1850015
Author(s):  
A.-B. A. Mohamed ◽  
M. S. Abdalla ◽  
A.-S. F. Obada
Keyword(s):  
Steady State ◽  
Quantum Correlation ◽  
Quantum Discord ◽  
Bell State ◽  
Analytical Description ◽  
Quantum Correlations ◽  
Total System ◽  
Intrinsic Decoherence ◽  
Geometric Quantum Discord ◽  
Phase Decoherence

Two two-level systems generated by su(2) algebra are initially prepared in a maximum nonsymmetric Bell state and having no mutual interaction. Each su(2)-system spatially interacts with two-mode cavity field in the nondegenerate parametric amplifier type cast through operators governed by su(1, 1) Lie algebra. An analytical description for the time evolution of the final state of the total system with the effect of intrinsic decoherence is found. Therefore, the robustness of the quantum correlations between the two su(2)-system is investigated by means of geometric quantum discord, measurement-induced nonlocality and negativity. We analyze in some detail the influence of initial coherence intensities, detuning and phase decoherence parameters on the steady-state correlation. We find that the steady-state correlations can be generated and enhanced by controlling the parameters of: the initial coherence intensities, the Bargmman index and the detuning. It is shown that the phenomenon of sudden death and re-birth of entanglement, and the sudden changes of the geometric quantum correlation can be controlled by these parameters. We find that the robustness of the quantum correlation can be greatly enhanced by the Bargmman index and the resonance detuning. Negativity is the measure most susceptible to phase decoherence, while geometric quantum discord and measurement-induced nonlocality are the more robust measures.

Dense Coding in Two Kinds of Two-Qubit Spin Squeezing Model

2019 ◽  
Vol 58 (10) ◽  
pp. 3602-3610 ◽  
Author(s):  
Yong-Qiang Li ◽  
Xiao Zhao ◽  
Xiang-Fu Jia ◽  
Guo-Hui Yang
Keyword(s):  
Spin Squeezing ◽  
Dense Coding ◽  
Spin Squeezing Model
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