Dynamics of quantum correlations for two-qubit coupled to a spin chain with Dzyaloshinskii-Moriya interaction

TL;DR

This paper investigates how quantum discord and entanglement evolve over time for two qubits coupled to a spin chain with Dzyaloshinskii-Moriya interaction, revealing critical behavior effects and decoherence phenomena.

Contribution

It provides analytical and numerical analysis of quantum correlation dynamics in a spin chain environment with DM interaction, highlighting the impact of environment criticality and anisotropy.

Findings

Quantum correlations decay rapidly at the environment's critical point.

Quantum discord can be maximized due to environmental criticality while entanglement vanishes.

Sudden transition between classical and quantum decoherence observed.

Abstract

We study the dynamics of quantum discord and entanglement for two spin qubits coupled to a spin chain with Dzyaloshinsky-Moriya (DM) interaction. We numerically and analytically investigate the time evolution of quantum discord and entanglement for two-qubit initially prepared in a class of $X-$structure state. In the case of evolution from a pure state, quantum correlations decay to zero in a very short time at the critical point of the environment. In the case of evolution from a mixed state, It is found that quantum discord may get maximized due to the quantum critical behavior of the environment while entanglement vanishes under the same condition. Moreover, we observed sudden transition between classical and quantum decoherence when single qubit interacts with the environment. The effects of DM interaction on quantum correlations are also considered and revealed in the two cases. It can enhance the decay of quantum correlations and its effect on quantum correlations can be strengthened by anisotropy parameter.