Detection of MEMS Acoustics via Scanning Tunneling Microscopy

TL;DR

This paper demonstrates a novel method combining STM and MEMS to perform high-precision, minimally invasive measurements of high-Q MEMS resonators at cryogenic temperatures, enabling access to their intrinsic dynamics.

Contribution

It introduces a new approach that unites STM and MEMS for non-invasive, high-precision measurements of micro-scale resonators, expanding capabilities in quantum and nanomechanical sensing.

Findings

Resolved acoustic modes of high-Q membranes with picometer precision

Achieved measurements without lasers or capacitive coupling

Enabled access to intrinsic dynamics of microgram oscillators

Abstract

Scanning tunneling microscopy (STM) and micro-electromechanical systems (MEMS) have traditionally addressed vastly different length scales - one resolving atoms, the other engineering macroscopic motion. Here we unite these two fields to perform minimally invasive-measurements of high aspect-ratio MEMS resonators using the STM tip as both actuator and detector. Operating at cryogenic temperatures, we resolve acoustic modes of millimeter-scale, high-Q membranes with picometer spatial precision, without making use of lasers or capacitive coupling. The tunneling junction introduces negligible back-action or heating, enabling direct access to the intrinsic dynamics of microgram-mass oscillators. In this work we explore three different measurement modalities, each offering unique advantages. Combined, they provide a pathway to quantum-level readout and exquisite high-precision measurements of forces, displacements, and pressures at cryogenic conditions. This technique provides a general platform for minimally-perturbative detection across a wide range of nanomechanical and quantum devices.