Quantum Correlation via Skew Information and Bell Function Beyond Entanglement in a Two-Qubit Heisenberg XYZ Model: Effect of the Phase Damping (original) (raw)
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Alexandria Engineering Journal, 2024
In this paper, we explore nonlocal correlation and Bell non-locality in a two-qubit Heisenberg XYZ model by using Bell-CHSH inequality and uncertainty induced nonlocality (UIN) as well as log-negativity. We consider the effects of spin-qubits XYZ-Heisenberg couplings, the-component of DM interaction, and intrinsic decoherence. Our results show that spin-qubits Heisenberg couplings have a strong ability to create two-qubit nonlocal correlations, enhanced by combining with DM interactions. The generated Bell-CHSH nonlocality and entanglement conform to the hierarchy principle. The UIN correlation is more resistant to intrinsic decoherence compared to Bell-CHSH inequality and log-negativity. Intrinsic decoherence causes the disappearance of Bell-CHSH non-locality and log-negativity entanglement, while leading to the appearance of partial stationary spin-qubits UIN correlation.
Correlations dynamics of two-spin XY Z Heisenberg model via negativity and skew information
World Scientific Publishing Company, 2022
We introduce a new framework for quantum two-spin correlations based on a quantum skew information quantity and long-negativity. The quantum correlations for an anisotropic twoqubit Heisenberg XYZ model are a®ected by physical parameters such as intrinsic decoherence, Werner states and time-dependent magnetic¯elds. In particular, the joint e®ects of Werner states, magnetic¯elds and anisotropic parameters on quantum correlation robustness are investigated in the presence of intrinsic decoherence. For an initially uncorrelated state, robust entanglement is generated while skew information between the two quantum bits no longer exists. It is shown that the magnetic¯eld makes the system strongly correlated with incredibly signi¯cant steady-state values in uncorrelated states. The phenomenon of sudden death and sudden birth appear during the evolution process of initial conditions. Finally, if the system starts from a mixed state or a Werner state, the magnetic¯eld does not play a signi¯cant role in the monotonically decreasing correlations. By leveraging our framework, one can create a kind of stability between the uncertainty-induced quantum nonlocality and the local quantum uncertainty correlations.
Thermal Fisher and Wigner-Yanase information correlations in two-qubit Heisenberg XYZ chain
Results in Physics , 2023
Using Wigner-Yanase and Fisher information [including local quantum uncertainty (LQU) and local quantum Fisher information (LQFI)] as well as log-negativity, we investigate the thermal non-local correlations of twoqubit Heisenberg XYZ non-X states produced in the presence of the Dzyaloshinskii-Moriya (DM) interaction. The two-spin XYZ-Heisenberg non-local correlation decay can be weakened by increasing the DM interaction as well as the spin-spin XYZ-Heisenberg interactions. The LQFI correlation has greater resistance to thermal degradation. The spin-spin-component antiferromagnetic coupling has a higher ability to protect the generated spin-spin nonlocal correlations against high temperatures. The emergence of the phenomena of the sudden death of log-negativity and the sudden change of the LQFI and LQU depend on the spin-spin XYZ-Heisenberg and DM interactions as well as on the bath temperature. The generated asymmetric correlations resulting due to the ,-component spin interactions confirm that the antiferromagnetic coupling has a high ability to generate a maximally correlated two-qubit state. While the generated correlations, due to twospin-component interaction, present symmetric dynamics, and its amount depends on the-component spin interaction.
Physical Review A, 2011
We study the effect of Dzyaloshinskii-Moriya (DM) interaction on pairwise quantum discord, entanglement, and classical correlation in the anisotropic XY spin-half chain. Analytical expressions for both quantum and classical correlations are obtained from the spin-spin correlation functions. We show that these pairwise quantities exhibit various behaviors in relation to the relative strengths of the DM interaction, the anisotropy and the magnetic intensity. We observe non-analyticities of the derivatives of both quantum and classical correlations with respect to the magnetic intensity at the critical point, with consideration of the DM interaction.
Various Correlations in the Anisotropic Heisenberg XYZ Model with Dzyaloshinski—Moriya Interaction
Chinese Physics Letters, 2013
Various thermal correlations as well as the effect of intrinsic decoherence on the correlations are studied in a two-qubit Heisenberg XYZ spin chain with the Dzyaloshinski-Moriya (DM) interaction along the z direction (Dz). It is found that tunable parameter Dz may play a constructive role to the concurrence (C), classical correlation (CC) and quantum discord (QD) in thermal equilibrium while it plays a destructive role to the C, CC and QD in the intrinsic decoherence case.
International Journal of Theoretical Physics, 2020
In the present paper, the quantum entanglement dynamics of two qubits Heisenberg-XYZ spin chain under a time dependent magnetic field effects, and considering the Dzyaloshinskii-Moriya (DM) interactions is studied. Assuming the system as being influenced by a non-Markovian environment, the dynamics of entanglement through the concurrence is studied. It follows from the simulations that the time dependency character of the DM coupling, the external magnetic field, and the Heisenberg spin-spin coupling preserves longer entanglement in the system compared to the case with these parameters constant. Moreover, it also follows that the effects of the environment on the system induces the loss of entanglement and then, the time interval of entanglement sudden death highly depends on the initial state considered. It is also observed that by tuning the strength of the DM coupling associated with a time varying magnetic field and a time varying spinspin anisotropic coupling, the system can be better protected from unwanted effects of the environment and thus, entanglement can be preserved for a longer period of time.
Dynamics of quantum correlations in two-qubit systems within non-Markovian environments
International Journal of Modern Physics B 27, 1345053, 2012
Knowledge of the dynamical behavior of correlations with no classical counterpart, like entanglement, nonlocal correlations and quantum discord, in open quantum systems is of primary interest because of the possibility to exploit these correlations for quantum information tasks. Here we review some of the most recent results on the dynamics of correlations in bipartite systems embedded in non-Markovian environments that, with their memory effects, influence in a relevant way the system dynamics and appear to be more fundamental than the Markovian ones for practical purposes. Firstly, we review the phenomenon of entanglement revivals in a two-qubit system for both independent environments and a common environment. We then consider the dynamics of quantum discord in non-Markovian dephasing channel and briefly discuss the occurrence of revivals of quantum correlations in classical environments.
2012
We consider the quantum correlations (entanglement and quantum discord) dynamics of two coupled spin qubits with Dzyaloshinsky-Moriya interaction influenced by a locally external magnetic field along z-direction and coupled to bath spin-1 2 particles as independent non-Markovian environment. We find that with increasing D z and decreasing J z , the value of entanglement and quantum discord increase for both antiferromagnetic and ferromagnetic materials. Not that, this growth is more for the ferromagnetic materials. In addition, we perceive that entanglement and quantum discord decrease with increased temperature and increased coupling constants between reduced system and bath. But, strong quantum correlations within the spins of bath reduce decoherence effects. We discuss about type of the constituent material of the central spins that it can speedup the quantum information processing and as a result, we perceive that one can improve and control the quantum information processing with correct selection of the properties of the reduced system (J, J z , D z).
2023
This study explores the dynamics of the formation of quantum correlations, namely: local quantum Fisher information and concurrence in a two-spin Heisenberg XXX system. The-direction of Kaplan-Shekhtman-Entin-Wohlman-Aharony (KSEA) and Dzyaloshinskii-Moriya (DM) interactions as well as the intrinsic decoherence are considered. We show that the interactions are responsible of transforming separable states to correlated states. We point out that by strengthening the two-spin antiferromagnetic interaction coupling, it is possible to increase the capacity to develop semi-regularly maximal two-spin correlations. By increasing the DM and KSEA-components, the two-spin XXX-Heisenberg exalts maximal local Fisher information and concurrence correlations with large amplitudes and high frequencies. As the intrinsic decoherence increases, the amplitudes and frequencies of the correlations decrease, which also causes the phenomena of sudden deathbirth and sudden changes of the correlations. The two-spin correlation produced by the unitary-component interactions can be shielded from the intrinsic decoherence by increasing the two-spin antiferromagnetic interaction coupling.
2014
We investigate the exact entanglement dynamics of a two-qubit Heisenberg XXZ chain with Dzyaloshinskii-Moriya (DM) interactions, interacting with an anisotropic spin bath in thermal equi- librium at a temperature T, driven by an external magnetic field B along the z-axis. We establish that, for an initially entangled qubit pair, the DM interactions generate entanglement and enhance the entanglement in the revival region. The effects of the DM interaction are also seen to be very important at high temperatures and for weak coupling between the two qubits where it is seen to preserve entanglement. These effects are weakened when the magnetic field B and the Heisenberg coupling are switched on. If the two-qubits are prepared in an initially separable state, the DM in- teraction instead has a negative effect on their entanglement. On a whole entanglement can better be preserve in the spin chain even at high temperatures by increases the external magnetic field B and the Heisenberg couplings, and by tuning the strength of the DM interaction.