Single-Phonon Addition and Subtraction to a Mechanical Thermal State

TL;DR

This paper demonstrates experimentally that adding or subtracting a single phonon to a mechanical thermal state can nearly double its mean occupation, using Brillouin optomechanics and advanced detection techniques.

Contribution

First experimental demonstration of single-phonon addition and subtraction effects on a mechanical thermal state outside optics.

Findings

Doubling of mechanical thermal fluctuations observed.

Implementation via Brillouin optomechanics in microresonators.

Enhanced detection scheme combining photon counting and heterodyne detection.

Abstract

Adding or subtracting a single quantum of excitation to a thermal state of a bosonic system has the counter-intuitive effect of approximately doubling its mean occupation. We perform the first experimental demonstration of this effect outside optics by implementing single-phonon addition and subtraction to a thermal state of a mechanical oscillator via Brillouin optomechanics in an optical whispering-gallery microresonator. Using a detection scheme that combines single-photon counting and optical heterodyne detection, we observe this doubling of the mechanical thermal fluctuations to a high precision. The capabilities of this joint click-dyne detection scheme adds a significant new dimension for optomechanical quantum science and applications.