Radiation Damping of a Polarizable Particle

TL;DR

This paper derives a relativistic expression for radiation damping of a polarizable particle in an electromagnetic field, linking classical and quantum effects to explain particle cooling and heating balance.

Contribution

It introduces a new relativistic formula for radiation damping force based on scattered power, connecting classical electromagnetic theory with quantum mechanical heating effects.

Findings

Radiation damping depends solely on scattered power.

Equilibrium temperature relates to field frequency and particle mass.

Damping is relativistic; heating stems from quantum radiation pressure.

Abstract

A polarizable body moving in an external electromagnetic field will slow down. This effect is referred to as radiation damping and is analogous to Doppler cooling in atomic physics. Using the principles of special relativity we derive an expression for the radiation damping force and find that it solely depends on the scattered power. The cooling of the particle's center-of-mass motion is balanced by heating due to radiation pressure shot noise, giving rise to an equilibrium that depends on the ratio of the field's frequency and the particle's mass. While damping is of relativistic nature heating has it's roots in quantum mechanics.