A room-temperature mechanical oscillator undergoes thermal Brownian motion with an amplitude much larger than the amplitude associated with a single phonon of excitation. This motion can be read out and manipulated using laser light using a cavity-optomechanical approach. By performing a strong quantum measurement, i.e., counting single photons in the sidebands imparted on a laser, we herald the addition and subtraction of single phonons on the 300K thermal motional state of a 4GHz mechanical oscillator. To understand the resulting mechanical state, we implement a tomography scheme and observe highly non-Gaussian phase-space distributions. Using a maximum likelihood method, we infer the density matrix of the oscillator and confirm the counter-intuitive doubling of the mean phonon number resulting from phonon addition and subtraction.
@article{arxiv.2102.04017,
title = {Room-temperature Mechanical Resonator with a Single Added or Subtracted Phonon},
author = {Rishi N. Patel and Timothy P. McKenna and Zhaoyou Wang and Jeremy D. Witmer and Wentao Jiang and Raphaël Van Laer and Christopher J. Sarabalis and Amir H. Safavi-Naeini},
journal= {arXiv preprint arXiv:2102.04017},
year = {2021}
}