Steady motional entanglement between two distant levitated nanoparticles

TL;DR

This paper proposes a method to generate and verify steady motional entanglement between two distant levitated nanoparticles using ultrastrong optomechanical coupling and entanglement swapping, feasible at room temperature over 10 km.

Contribution

It introduces a novel scheme for steady remote entanglement of macroscopic nanoparticles via ultrastrong optomechanical coupling and entanglement swapping, with realistic experimental parameters.

Findings

Steady motional entanglement can be achieved over 10 km distance.

Ultrastrong optomechanical coupling enables large entanglement.

Room temperature entanglement is feasible with current technology.

Abstract

Quantum entanglement in macroscopic systems is not only essential for practical quantum information processing, but also valuable for the study of the boundary between quantum and classical world. However, it is very challenge to achieve the steady remote entanglement between distant macroscopic systems. We consider two distant nanoparticles, both of which are optically trapped in two cavities. Based on the coherent scattering mechanism, we find that the ultrastrong optomechanical coupling between the cavity modes and the motion of the levitated nanoparticles could achieve. The large and steady entanglement between the filtered output cavity modes and the motion of nanosparticles can be generated, if the trapping laser is under the red sideband. Then through entanglement swapping, the steady motional entanglement between the distant nanoparticles can be realized. We numerically simulate and find that the two nanoparticles with 10 km distance can be entangled for the experimentally feasible parameters, even in room temperature environment.