Fabrication processes involving anhydrous hydrofluoric vapor etching are developed to create high-Q aluminum superconducting microwave resonators on free-standing silicon membranes formed from a silicon-on-insulator wafer. Using this fabrication process, a high-impedance 8.9GHz coil resonator is coupled capacitively with large participation ratio to a 9.7MHz micromechanical resonator. Two-tone microwave spectroscopy and radiation pressure back-action are used to characterize the coupled system in a dilution refrigerator down to temperatures of Tf=11~mK, yielding a measured electromechanical vacuum coupling rate of g0/2π≈24.6~Hz and a mechanical resonator Q-factor of Qm=1.7×107. Microwave back-action cooling of the mechanical resonator is also studied, with a minimum phonon occupancy of nm≈16 phonons being realized at an elevated fridge temperature of Tf=211~mK.
@article{arxiv.1601.04019,
title = {Superconducting cavity-electromechanics on silicon-on-insulator},
author = {Paul B. Dieterle and Mahmoud Kalaee and Johannes Fink and Oskar Painter},
journal= {arXiv preprint arXiv:1601.04019},
year = {2016}
}