Steady-state entanglement of interacting masses in free space through optimal feedback control

TL;DR

This paper presents an optimal feedback control method to generate and maintain steady-state entanglement between two interacting masses in free space, surpassing traditional cooling strategies.

Contribution

It introduces a linear quadratic Gaussian control scheme with EPR-type constraints for unconditional entanglement in Gaussian systems.

Findings

Achieves stationary entanglement where cooling strategies fail

Uses LQG control to engineer phase space dynamics

Facilitates unconditional entanglement generation

Abstract

We develop a feedback strategy based on optimal quantum feedback control for Gaussian systems to maximise the likelihood of steady-state entanglement detection between two directly interacting masses. We employ linear quadratic Gaussian (LQG) control to engineer the phase space dynamics of the two masses and propose Einstein-Podolsky-Rosen (EPR)-type variance minimisation constraints for the feedback to facilitate unconditional entanglement generation. This scheme allows for stationary entanglement in parameter regimes where strategies based on total energy minimisation cooling would fail.