Velocity dependence of the quantum friction force on an atom near a dielectric surface

TL;DR

This paper examines different theoretical predictions for the velocity dependence of quantum friction on an atom near a dielectric surface, arguing that the force is linearly proportional to velocity, contrary to some claims of a cubic dependence.

Contribution

The authors clarify the velocity dependence of quantum friction, showing it aligns with linear models rather than the cubic dependence suggested by some previous approaches.

Findings

Force is proportional to velocity, not velocity cubed.

Oversimplified oscillator models lead to incorrect cubic dependence.

Theoretical analysis supports linear velocity dependence of quantum friction.

Abstract

Different approaches to the problem of the "quantum friction" force F acting on an atom moving with velocity v<<c parallel to a dielectric surface have resulted in different predictions for the way in which F depends on v. For instance, Scheel and Buhmann [Phys. Rev. A 80, 042902 (2009)] and Barton [New J. Phys. 12, 113045 (2010)] and others find a force linear in v, while Intravaia, Behunin, and Dalvit [arXiv:1308.0712, 2013] and others find that the force varies as v^3 to lowest order in v. We argue that the F proportional to v^3 prediction results from an oversimplified treatment of the atom as a linear oscillator, and that F depends on v in just the way predicted by Scheel and Buhmann and Barton.