Minimization of phonon-tunneling dissipation in mechanical resonators

TL;DR

This paper introduces a numerical method to predict and experimentally verify support-induced losses in micro- and nanoscale mechanical resonators, advancing understanding and control of mechanical damping for improved device performance.

Contribution

It presents a new phonon-tunneling based numerical solver and demonstrates its accuracy in predicting support-induced losses through experimental validation.

Findings

Support-induced losses depend strongly on device geometry.

The phonon-tunneling model accurately predicts damping in resonators.

Device engineering can significantly reduce mechanical dissipation.

Abstract

Micro- and nanoscale mechanical resonators have recently emerged as ubiquitous devices for use in advanced technological applications, for example in mobile communications and inertial sensors, and as novel tools for fundamental scientific endeavors. Their performance is in many cases limited by the deleterious effects of mechanical damping. Here, we report a significant advancement towards understanding and controlling support-induced losses in generic mechanical resonators. We begin by introducing an efficient numerical solver, based on the "phonon-tunneling" approach, capable of predicting the design-limited damping of high-quality mechanical resonators. Further, through careful device engineering, we isolate support-induced losses and perform the first rigorous experimental test of the strong geometric dependence of this loss mechanism. Our results are in excellent agreement with theory, demonstrating the predictive power of our approach. In combination with recent progress on complementary dissipation mechanisms, our phonon-tunneling solver represents a major step towards accurate prediction of the mechanical quality factor.