Dynamics of quantum correlations for central two-qubit coupled to an isotropic Lipkin-Meshkov-Glick bath

TL;DR

This paper studies how quantum correlations like discord and entanglement evolve over time for two qubits interacting with an isotropic Lipkin-Meshkov-Glick bath, revealing phase-dependent behaviors and critical points.

Contribution

It demonstrates the distinct dynamics of quantum discord and entanglement across different bath phases and identifies the bath's quantum phase transition through correlation behaviors.

Findings

Quantum discord remains constant in the symmetry broken phase.

Quantum discord and entanglement oscillate periodically in the symmetric phase.

Quantum discord is significantly enhanced during evolution while entanglement periodically vanishes.

Abstract

We investigate the dynamics of quantum discord and entanglement for two central spin qubits coupled to an isotropic Lipkin-Meshkov-Glick bath. It is found that both quantum discord and entanglement have quite distinct behaviors with respect to the two different phases of the bath. In the case of the symmetry broken phase bath, quantum discord and entanglement can remain as constant. In the case of the symmetric phase bath, quantum discord and entanglement always periodically oscillate with time. The critical point of quantum phase transition of the bath can be revealed clearly by the distinct behaviors of quantum correlations. Furthermore, it is observed that quantum discord is significantly enhanced during the evolution while entanglement periodically vanishes.