Accessing nanomechanical resonators via a fast microwave circuit

TL;DR

This paper introduces a novel electrical detection method for conductive nanomechanical resonators up to 200 MHz, eliminating the need for magnetic fields or cryogenic conditions, and discusses potential quantum limit approaches.

Contribution

The paper presents a new microwave-based technique for fully electrical detection of nanomechanical vibrations without external magnetic fields or cryogenics.

Findings

Detects nanomechanical vibrations up to 200 MHz

Uses LC tank circuit to modulate and detect vibrations

Estimates approach to quantum limit of mechanical systems

Abstract

The measurement of micron-sized mechanical resonators by electrical techniques is difficult, because of the combination of a high frequency and a small mechanical displacement which together suppress the electromechanical coupling. The only electromagnetic technique proven up to the range of several hundred MHz requires the usage of heavy magnetic fields and cryogenic conditions. Here we show how, without the need of either of them, to fully electrically detect the vibrations of conductive nanomechanical resonators up to the microwave regime. We use the electrically actuated vibrations to modulate an LC tank circuit which blocks the stray capacitance, and detect the created sideband voltage by a microwave analyzer. We show the novel technique up to mechanical frequencies of 200 MHz. Finally, we estimate how one could approach the quantum limit of mechanical systems.