Optomechanical crystals (OMCs) enable coherent interactions between optical photons and microwave acoustic phonons, and represent a platform for implementing quantum transduction between microwave and optical signals. Optical absorption-induced thermal noise at cryogenic (millikelvin) temperatures is one of the primary limitations of performance for OMC-based quantum transducers. Here, we address this challenge with a two-dimensional silicon OMC resonator that is side-coupled to a mechanically detached optical waveguide, realizing a six-fold reduction in the heating rate of the acoustic resonator compared to prior state-of-the-art, while operating in a regime of high optomechanical-backaction and millikelvin base temperature. This reduced heating translates into a demonstrated phonon-to-photon conversion efficiency of 93.1 ± 0.8% at an added noise of 0.25 ± 0.01 quanta, representing a significant advance toward quantum-limited microwave-optical frequency conversion and optically-controlled quantum acoustic memories.
@article{arxiv.2406.15701,
title = {High-Efficiency Low-Noise Optomechanical Crystal Photon-Phonon Transducers},
author = {Sameer Sonar and Utku Hatipoglu and Srujan Meesala and David Lake and Hengjiang Ren and Oskar Painter},
journal= {arXiv preprint arXiv:2406.15701},
year = {2024}
}