Magnetic effects on nonlinear mechanical properties of a suspended carbon nanotube

TL;DR

This paper presents a microscopic model demonstrating how an external magnetic field can tune the nonlinear mechanical properties of a suspended carbon nanotube, affecting damping, noise, and resonance frequencies.

Contribution

It introduces a novel microscopic model showing magnetic field control over nonlinear mechanical behavior of CNTs in nanoelectromechanical systems.

Findings

Magnetic field induces enhanced damping and noise in CNT dynamics.

Quality factor shows quadratic dependence on magnetic field strength.

Resonance frequencies exhibit a dip-peak structure with increasing magnetic field.

Abstract

We propose a microscopic model for a nanoelectromechanical system made by a radio-frequency driven suspended carbon nanotube (CNT) in the presence of an external magnetic field perpendicular to the current. As a main result, we show that, when the device is driven far from equilibrium, one can tune the CNT mechanical properties by varying the external magnetic field. Indeed, the magnetic field affects the CNT bending mode dynamics inducing an enhanced damping as well as a noise term due to the electronic phase fluctuations. The quality factor, as observed experimentally, exhibits a quadratic dependence on external magnetic field strength. Finally, CNT resonance frequencies as a function of gate voltage acquire, increasing the magnetic field strength, a peculiar dip-peak structure that should be experimentally observed.