Quantum Discord Surge Heralds Entanglement Revival in an Infinite Spin Chain

TL;DR

This paper investigates how quantum discord can predict entanglement revival in an infinite quantum XY spin chain subjected to a time-dependent transverse field, revealing a correlation between discord increase and entanglement resurgence.

Contribution

It demonstrates that quantum discord serves as a predictor for entanglement revival in a nonequilibrium quantum spin system, linking quantum correlations to entanglement dynamics.

Findings

Entanglement revival correlates with increased quantum discord.

Quantum discord predicts entanglement behavior in a spin chain.

Results are applicable to current quantum technology implementations.

Abstract

A measure of quantum correlation defined from an information-theoretic perspective, namely, quantum discord, is applied to study the time-evolved nonequilibrium state of the infinite anisotropic quantum XY spin chain in a transverse time-dependent field. In particular, we probe whether the collapse and revival of nearest-neighbor entanglement of the state seen with a varying initial applied field strength, at a fixed evolution time, may be predicted from the behavior of the quantum correlation measure. For this quantum many-body system, realizable with currently available technology, we find that the revival of entanglement of the evolved state occurs if there is an increase in quantum discord in the vicinity of entanglement collapse.