Probing nonlinear mechanical effects through electronic currents: the case of a nanomechanical resonator acting as electronic transistor

TL;DR

This paper models a suspended carbon nanotube as a self-detecting transistor, revealing how nonlinear mechanical vibrations influence electronic current signals, with implications for understanding nanoelectromechanical systems.

Contribution

It introduces a comprehensive model capturing nonlinear mechanical effects on electronic currents in a nanomechanical resonator acting as a transistor, aligning well with experimental observations.

Findings

Current peaks indicate mechanical resonance at low currents.

Current dips occur in high current regimes.

Nonlinear effects cause asymmetric current-frequency responses.

Abstract

We study a general model describing a self-detecting single electron transistor realized by a suspended carbon nanotube actuated by a nearby antenna. The main features of the device, recently observed in a number of experiments, are accurately reproduced. When the device is in a low current-carrying state, a peak in the current signals a mechanical resonance. On the contrary, a dip in the current is found in high current-carrying states. In the nonlinear vibration regime of the resonator, we are able to reproduce quantitatively the characteristic asymmetric shape of the current-frequency curves. We show that the nonlinear effects coming out at high values of the antenna amplitude are related to the effective nonlinear force induced by the electronic flow. The interplay between electronic and mechanical degrees of freedom is understood in terms of an unifying model including in an intrinsic way the nonlinear effects driven by the external probe.