Quantum discord and entanglement in Heisenberg XXZ spin chain after quenches

TL;DR

This paper investigates how quantum discord and entanglement evolve over time in a Heisenberg XXZ spin chain after interaction quenches, revealing discord's ability to signal phase transitions.

Contribution

It introduces a detailed analysis of quantum discord dynamics in quenched XXZ chains using advanced numerical methods, highlighting discord's unique role in detecting phase transitions.

Findings

Quantum discord predicts quantum phase transitions.

Entanglement and discord oscillate before stabilizing.

Discord remains a reliable indicator of phase changes.

Abstract

Using the adaptive time-dependent density-matrix renormalization group method, the dynamics of entanglement and quantum discord of a one-dimensional spin-1/2 XXZ chain is studied when anisotropic interaction quenches are applied at different temperatures. The dynamics of the quantum discord and pairwise entanglement between the nearest qubits shows that the entanglement and quantum discord will first oscillate and then approach to a constant value. The quantum discord can be used to predict the quantum phase transition, while the entanglement cannot.