Carbon nanotubes: Nonlinear high-Q resonators with strong coupling to single-electron tunneling

TL;DR

This paper explores the nonlinear dynamics of carbon nanotube resonators, highlighting their strong coupling to single-electron tunneling and potential for advanced sensing and mode coupling studies.

Contribution

It introduces methods to detect CNT resonator motion, analyzes various nonlinear effects, and demonstrates their suitability for parametric excitation and mode coupling research.

Findings

Single-electron tunneling causes sharp dips in resonance frequency.

CNT resonators exhibit multiple nonlinear oscillation mechanisms.

Resonance frequency is highly sensitive to gate voltage and tension.

Abstract

Carbon nanotubes (CNTs) are nonlinear high-Q resonators with strong coupling to single-electron tunneling. We begin by describing several methods to detect the flexural motion of a CNT resonator. Next, we illustrate how single-electron tunneling in quantum dot CNT resonators leads to sharp dips in the mechanical resonance frequency and significant damping. We discuss four different contributions to the nonlinear oscillation of a CNT resonator: beam-like mechanical nonlinearity, nonlinearity due to gate-induced mechanical tension, electrostatic nonlinearity, and nonlinearity due to single-electron tunneling, and provide quantitative estimates of their strengths. Finally, we show how the large response of the resonance frequency of a CNT resonator to a change in gate voltage or tension makes CNT resonators ideally suited for parametric excitation and for studying the coupling between different mechanical modes.