Quantum entanglement in a four-partite hybrid system containing three macroscopic subsystems

TL;DR

This paper investigates a complex four-partite quantum system with macroscopic subsystems, demonstrating the generation of steady-state entanglement between different pairs, including atomic ensembles, mechanical mirrors, and LC circuits, under realistic conditions.

Contribution

It introduces a hybrid four-partite quantum system with three macroscopic subsystems and shows how to generate and analyze entanglement among them using a cavity field.

Findings

Steady-state bipartite Gaussian entanglement can be achieved between subsystems.

Entanglement between atomic ensemble and LC circuit is feasible for quantum memory and processing.

Environmental temperature affects the degree of quantum entanglement.

Abstract

The combination of different quantum systems may allow the exploration of the distinctive features of each system for the investigation of fundamental phenomena as well as for quantum technologies. In this work we consider a setup consisting of an atomic ensemble enclosed within a laser-driven optomechanical cavity, having the moving mirror further (capacitively) coupled to a low frequency LC circuit. This constitutes a four-partite optoelectromechanical quantum system containing three macroscopic quantum subsystems of a different nature, viz, the atomic ensemble, the massive mirror and the LC circuit. The quantized cavity field plays the role of an auxiliary system that allows the coupling of two other quantum subsystems. We show that for experimentally achievable parameters, it is possible to generate steady state bipartite Gaussian entanglement between pairs of macroscopic systems. In particular, we find under which conditions it is possible to obtain a reasonable amount of entanglement between the atomic ensemble and the LC circuit, systems that might be suitable for constituting a quantum memory and for quantum processing, respectively. For complementarity, we discuss the effect of the environmental temperature on quantum entanglement.