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.
@article{arxiv.2006.11599,
title = {Single-Phonon Addition and Subtraction to a Mechanical Thermal State},
author = {Georg Enzian and John J. Price and Lars Freisem and Joshua Nunn and Jiri Janousek and Ben C. Buchler and Ping Koy Lam and Michael R. Vanner},
journal= {arXiv preprint arXiv:2006.11599},
year = {2021}
}