Brownian motion of a charged test particle near a reflecting boundary at finite temperature

TL;DR

This paper investigates how quantum electromagnetic fluctuations influence the random motion of charged particles near a reflecting boundary at finite temperature, revealing conditions where quantum effects dominate over thermal noise.

Contribution

It provides a detailed analysis of quantum fluctuation-induced motion near boundaries at finite temperature, highlighting the conditions where quantum effects surpass thermal noise.

Findings

Quantum-driven motion is generally less significant than thermal noise in unbounded space.

Near a reflecting boundary at low temperature, quantum effects can dominate over thermal fluctuations.

The study quantifies mean squared velocity and position fluctuations due to quantum and thermal effects.

Abstract

We discuss the random motion of charged test particles driven by quantum electromagnetic fluctuations at finite temperature in both the unbounded flat space and flat spacetime with a reflecting boundary and calculate the mean squared fluctuations in the velocity and position of the test particle. We show that typically the random motion driven by the quantum fluctuations is one order of magnitude less significant than that driven by thermal noise in the unbounded flat space. However, in the flat space with a reflecting plane boundary, the random motion of quantum origin can become much more significant than that of thermal origin at very low temperature.