Theory of charge density wave non-contact friction

TL;DR

This paper introduces a theoretical model explaining how charge density waves cause distance-dependent energy dissipation in atomic force microscopy, supported by simulations and experimental comparisons.

Contribution

It presents a novel mechanism linking charge density wave phase slips to non-contact friction, supported by numerical simulations and experimental data.

Findings

Model explains dissipation peaks in AFM over charge density wave surfaces

Simulations agree qualitatively with experimental observations

Hysteretic behavior of tip oscillations linked to phase slips

Abstract

A mechanism is proposed to describe the occurrence of distance-dependent dissipation peaks in the dynamics of an atomic force microscope tip oscillating over a surface characterized by a charge density wave state. The dissipation has its origin in the hysteretic behavior of the tip oscillations occurring at positions compatible with a localized phase slip of the charge density wave. This model is supported through static and dynamic numerical simulations of the tip surface interaction and is in good qualitative agreement with recently performed experiments on a NbSe$_2$ sample.