Stationary entanglement of a levitated oscillator with an optical field

TL;DR

This paper demonstrates the generation of stationary quantum entanglement between a levitated nanosphere's motion and an optical field at room temperature, highlighting its potential for quantum communication and macroscopic quantum tests.

Contribution

It reports the first observation of stationary entanglement in a levitated optomechanical system at room temperature, with full correlation reconstruction and violation of separability bounds.

Findings

Entanglement achieved at room temperature.

Violation of separability bounds observed.

Robust entanglement over broad parameters.

Abstract

Stationary entanglement between the motion of macroscopic objects and light is a long-standing goal of quantum optomechanics, with implications for both fundamental tests of quantum physics and emerging quantum technologies. We report the generation of quantum entanglement between the center-of-mass motion of a nanosphere levitated in an optical tweezer inside an optical cavity and the electromagnetic field. By heterodyne detection, we reconstruct the full set of optomechanical correlations and observe a violation of separability bounds between the mechanical motion and the quadratures of a propagating optical mode. This demonstrates the distribution of nonclassical correlations beyond the interaction region. The entanglement is generated at room temperature and remains robust over a broad range of parameters. Our results establish levitated optomechanical systems as a promising platform for continuous-variable quantum communication and for tests of macroscopic quantum physics.