Puglia, D., Odessey, R., Burns, P. S., Luhmann, N., Schmid, S., & Higginbotham, A. P. (2025). Room Temperature, Cavity-Free Capacitive Strong Coupling to Mechanical Motion. Nano Letters, 25(7), 2749–2755. https://doi.org/10.1021/acs.nanolett.4c05796
The back-action damping of mechanical motion by electromagnetic radiation is typically overwhelmed by internal loss channels unless demanding experimental ingredients such as superconducting resonators, high-quality optical cavities, or large magnetic fields are employed. Here we demonstrate the first room temperature, cavity-free, all-electric device where back-action damping exceeds internal loss, enabled by a mechanically compliant parallel-plate capacitor with a nanoscale plate separation and an aspect ratio exceeding 1,000. The device has 4 orders of magnitude lower insertion loss than a comparable commercial quartz crystal and achieves a position imprecision rivaling optical interferometers. With the help of a back-action isolation scheme, we observe radiative cooling of mechanical motion by a remote cryogenic load. This work provides a technologically accessible route to high-precision sensing, transduction, and signal processing.
