Entanglement in stationary nonequilibrium states at high energies

TL;DR

This paper demonstrates that in a one-dimensional spin chain, entanglement can exist in nonequilibrium stationary states at high energies, and it can be induced by strong driving but destroyed by dephasing.

Contribution

It analytically shows the presence of entanglement at high energies in nonequilibrium states of a spin chain, extending understanding beyond low-temperature equilibrium.

Findings

Entanglement exists at infinite temperature in driven spin chains.

Strong driving induces entanglement even at high energies.

Dissipative dephasing destroys entanglement.

Abstract

In recent years it has been found that quantum systems can posses entanglement in equilibrium thermal states provided temperature is low enough. In the present work we explore a possibility of having entanglement in nonequilibrium stationary states. We show analytically that, in a simple one-dimensional spin chain, there is entanglement even at highest attainable energies; that is, starting from an equilibrium state at infinite temperature, a sufficiently strong driving can induce entanglement, even in the thermodynamic limit. We also show that dissipative dephasing, on the other hand, destroys entanglement.