Near-field coupling of a levitated nanoparticle to a photonic crystal cavity

TL;DR

This paper demonstrates a nanophotonic system where a levitated nanoparticle is coupled to a photonic crystal cavity, significantly enhancing measurement sensitivity and coupling strength, paving the way for room temperature quantum optomechanics.

Contribution

The work introduces a novel near-field coupling method between a levitated nanoparticle and a photonic crystal cavity, achieving unprecedented optomechanical coupling and detection sensitivity.

Findings

Achieved tunable single-photon optomechanical coupling of 9 kHz.

Enhanced per-photon displacement sensitivity by two orders of magnitude.

Demonstrated potential for room temperature quantum optomechanics.

Abstract

Quantum control of levitated dielectric particles is an emerging subject in quantum optomechanics. A major challenge is to efficiently measure and manipulate the particle's motion at the Heisenberg uncertainty limit. Here we present a nanophotonic interface suited to address this problem. By optically trapping a 150 nm silica particle and placing it in the near field of a photonic crystal cavity, we achieve tunable single-photon optomechanical coupling of up to $g_0/2\pi=9$ kHz, three orders of magnitude larger than previously reported for levitated cavity optomechanical systems. Efficient collection and guiding of light through the nanophotonic structure results in a per-photon displacement sensitivity that is increased by two orders of magnitude compared to conventional far-field detection. The demonstrated performance shows a promising route for room temperature quantum optomechanics.