Anisotropic motion of an electric dipole in a photon gas near a flat conducting boundary

TL;DR

This paper investigates the quantum Brownian motion of a neutral electric dipole near a conducting boundary within a photon gas, revealing anisotropic motion, quantum dispersions, and a novel quantum cooling effect influenced by the environment.

Contribution

It introduces a detailed analysis of the anisotropic quantum motion of an electric dipole near a conducting wall, highlighting a new quantum cooling mechanism driven by vacuum fluctuations.

Findings

Dipole rotation energy exceeds translational energy under typical conditions.

Presence of the wall can reduce the particle's kinetic energy, indicating quantum cooling.

Observable effects include anisotropic dispersions and energy exchange with the vacuum.

Abstract

The quantum Brownian motion of a single neutral particle with nonzero electric dipole moment placed in a photon gas at fixed temperature and close to a conducting wall is here examined. The interaction of the particle with the photon field leads to quantum dispersions of its linear and angular momenta, whose magnitudes depend on the temperature, distance to the wall, and also on the dipole moment characteristics. It is shown that for typical experimental parameters the amount of energy held by the dipole rotation is expressively larger than the one related to the center of mass translation. Furthermore, the particle kinetic energy in presence of a thermal bath can decrease if the wall is added to the system, representing a novel quantum cooling effect where the work done by the quantum vacuum extracts energy from the particle. Finally, possible observable consequences are discussed.