Strong optomechanical coupling at room temperature by coherent scattering

Andrés De Los Ríos Sommer,Nadine Meyer,Romain Quidant

doi:10.1038/s41467-020-20419-2

Abstract

Quantum control of a system requires the manipulation of quantum states faster than any decoherence rate. For mesoscopic systems, this has so far only been reached by few cryogenic systems. An important milestone towards quantum control is the so-called strong coupling regime, which in cavity optomechanics corresponds to an optomechanical coupling strength larger than cavity decay rate and mechanical damping. Here, we demonstrate the strong coupling regime at room temperature between a levitated silica particle and a high finesse optical cavity. Normal mode splitting is achieved by employing coherent scattering, instead of directly driving the cavity. The coupling strength achieved here approaches three times the cavity linewidth, crossing deep into the strong coupling regime. Entering the strong coupling regime is an essential step towards quantum control with mesoscopic objects at room temperature.

Highlights

Quantum control of a system requires the manipulation of quantum states faster than any decoherence rate
After a decade of experimental and theoretical efforts employing the same techniques[1,2,3,4,5,6,7,8], the motional ground state of levitated silica nanoparticles at room temperature has been reported[9]. While this represents an important milestone towards the creation of mesoscopic quantum objects, coherent quantum control of levitated nanoparticles[10,11] still remains elusive
The trap is mounted on a nano-positioning stage allowing for precise 3D placement of the particle inside the low loss, high finesse Fabry-Pérot cavity with a cavity linewidth κ ≈ 2π × 10 kHz, cavity finesse F = 5.4 × 105 and free spectral range ΔωFSR = πc/Lc = 2π × 5.4 GHz

Summary

Introduction

Quantum control of a system requires the manipulation of quantum states faster than any decoherence rate. After a decade of experimental and theoretical efforts employing the same techniques[1,2,3,4,5,6,7,8], the motional ground state of levitated silica nanoparticles at room temperature has been reported[9] While this represents an important milestone towards the creation of mesoscopic quantum objects, coherent quantum control of levitated nanoparticles[10,11] still remains elusive. Cooling with CS is less sensitive to phase noise heating than actively driving the cavity[7,24], because optimal coupling takes place at the intensity node This has enabled phonon occupation numbers of less than one[9]

Methods

Results

Conclusion