Detection of mechanical resonance of a single-electron transistor by direct current

TL;DR

This paper demonstrates the detection of mechanical resonance in a suspended single-electron transistor by observing changes in current, combining experimental fabrication with simulations based on the orthodox model.

Contribution

It introduces a novel method to detect mechanical resonance in a single-electron transistor using direct current measurements and enhanced coupling via a bottom gate.

Findings

Resonance detected through current variations

Device modeled successfully with orthodox theory

Enhanced coupling improves mechanical detection sensitivity

Abstract

We have suspended an Al based single-electron transistor whose island can resonate freely between the source and drain leads forming the clamps. In addition to the regular side gate, a bottom gate with a larger capacitance to the SET island is placed underneath to increase the SET coupling to mechanical motion. The device can be considered as a doubly clamped Al beam that can transduce mechanical vibrations into variations of the SET current. Our simulations based on the orthodox model, with the SET parameters estimated from the experiment, reproduce the observed transport characteristics in detail.