Correlations and thermalization in driven cavity arrays

TL;DR

This paper demonstrates how long-distance quantum entanglement can be established and controlled in driven cavity arrays, revealing conditions for maximal entanglement and its relation to thermalization.

Contribution

It introduces a method to generate and control long-distance entanglement in cavity arrays, analyzing the effects of geometry, temperature, and driving strength.

Findings

Maximal entanglement occurs when direct coupling is much smaller than individual couplings.

Steady states at finite temperature are generally not thermal states.

The change in thermalization correlates with the entanglement degree.

Abstract

We show that long-distance steady-state quantum correlations (entanglement) between pairs of cavity-atom systems in an array of lossy and driven coupled resonators can be established and controlled. The maximal of entanglement for any pair is achieved when their corresponding direct coupling is much smaller than their individual couplings to the third party. This effect is reminiscent of the coherent trapping of the $\Lambda-$type three-level atoms using two classical coherent fields. Different geometries for coherent control are considered. For finite temperature, the steady state of the coupled lossy atom-cavity arrays with driving fields is in general not a thermal state. Using an appropriate distance measure for quantum states, we find that the change rate of the degree of thermalization with respect to the driving strength is consistent with the entanglement of the system.