Decoherence and Brownian motion of a polarizable particle near a surface

TL;DR

This paper investigates how electromagnetic field fluctuations near a surface cause classical Brownian motion and quantum decoherence of a polarizable particle, deriving a master equation linking classical diffusion and quantum localization.

Contribution

It introduces a position localization master equation for a polarizable particle's quantum motion near a medium, connecting classical and quantum Brownian behaviors.

Findings

Field fluctuations induce momentum diffusion and drag.

Derivation of a master equation for quantum position localization.

Illustration of classical-quantum correspondence in Brownian motion.

Abstract

We analyze the classical and quantized center-of-mass motion of a polarizable particle interacting with the fluctuations of the electromagnetic (EM) field in the presence of a medium. As a polarizable particle is immersed in a thermal environment, the momentum impulses imparted by the field fluctuations lead to momentum diffusion and drag for the particle's classical center of mass. When considering the quantized center-of-mass motion of the particle, these very fluctuations gain information about its position, leading to decoherence in the position basis. We derive a position localization master equation for the particle's quantized center of mass, and examine its classical center-of-mass momentum diffusion, elucidating correspondences between classical and quantum Brownian motion of polarizable particles near media.