Dynamics of nonequilibrium thermal entanglement

TL;DR

This paper analyzes how a two-spin system coupled to thermal baths evolves over time, revealing conditions that maximize and stabilize entanglement at steady state despite temperature differences.

Contribution

It provides an analytical solution for the system's reduced density matrix and explores how energy level differences influence entanglement stability.

Findings

Steady-state entanglement depends on bath temperature differences.

Maximum entanglement occurs at unequal bath temperatures when energy levels differ.

Energy level differences enhance entanglement stability at high temperatures.

Abstract

The dynamics of a simple spin chain (2 spins) coupled to bosonic baths at different temperatures is studied. The analytical solution for the reduced density matrix of the system is found. The dynamics and temperature dependence of spin-spin entanglement is analyzed. It is shown that the system converges to a steady-state. If the energy levels of the two spins are different, the steady-state concurrence assumes its maximum at unequal bath temperatures. It is found that a difference in local energy levels can make the steady-state entanglement more stable against high temperatures.