Coherent control of long-distance steady state entanglement in lossy resonator arrays

TL;DR

This paper demonstrates that long-distance steady-state entanglement between cavity-atom systems in lossy resonator arrays can be coherently controlled via phase tuning of driving fields, achieving high entanglement despite classical pumps.

Contribution

It introduces a method to control and maximize steady-state entanglement in lossy resonator arrays through phase adjustments, applicable to various implementations.

Findings

Steady-state entanglement can be coherently controlled by tuning phase differences.

High entanglement achievable despite classical driving fields.

Long-distance quantum correlations can be established via fibers.

Abstract

We show that coherent control of the steady-state long-distance entanglement between pairs of cavity-atom systems in an array of lossy and driven coupled resonators is possible. The cavities are doped with atoms and are connected through wave guides, other cavities or fibers depending on the implementation. We find that the steady-state entanglement can be coherently controlled through the tuning of the phase difference between the driving fields. It can also be surprisingly high in spite of the pumps being classical fields. For some implementations where the connecting element can be a fiber, long-distance steady state quantum correlations can be established. Furthermore, 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 establishment of coherence between otherwise uncoupled atomic levels using classical coherent fields. We suggest a method to measure this entanglement by analyzing the correlations of the emitted photons from the array and also analyze the above results for a range of values of the system parameters, different network geometries and possible implementation technologies.