Velocity effect on the stimulated transition process of a multilevel atom in a thermal bath

Huabing Cai

doi:10.1140/epjc/s10052-021-09477-y

Abstract

This paper investigates the stimulated transition process of a uniformly moving atom in interaction with a thermal bath of the quantum electromagnetic field. Using the perturbation theory, the atomic stimulated emission and absorption rates are calculated. The results indicate that the atomic transition rates depend crucially on the atomic velocity, the temperature of the thermal bath, and the atomic polarizability. As these factors change, the atomic stimulated transition processes can be enhanced or weakened at different degrees. In particular, slowly moving atoms in the thermal bath with high temperature (Tgg omega _{0}) perceive a smaller effective temperature T big ( 1-frac{1}{10} v^{2} big ) for the polarizability perpendicular to the atomic velocity or T big ( 1-frac{3}{10} v^{2} big ) for the polarizability parallel to the atomic velocity. However, ultra-relativistic atoms perceive no influence of the background thermal bath. In turn, in terms of the atomic transition rates, this paper explores and examines the relativity of temperature of the quantum electromagnetic field.

Highlights

Slowly moving atoms in the thermal bath with high temperature (T ω0) perceive a smaller effective temperature T
From a completely different point of view, Costa and Matas considered a uniformly moving Unruh–DeWitt detector coupled to a thermal bath of the massless quantum scalar field in the framework of the combination of quantum thermodynamics and special relativity [11]
Papadatos and Anastopoulos analyzed the thermodynamics of a quantum system in a trajectory of constant velocity that interacts with a static thermal bath of the massless quantum scalar field [18]

Summary

Introduction

The discovery of special relativity inevitably gives rise to the problem of constructing a relativistic thermodynamical theory. From a completely different point of view, Costa and Matas considered a uniformly moving Unruh–DeWitt detector coupled to a thermal bath of the massless quantum scalar field in the framework of the combination of quantum thermodynamics and special relativity [11]. Papadatos and Anastopoulos analyzed the thermodynamics of a quantum system in a trajectory of constant velocity that interacts with a static thermal bath of the massless quantum scalar field [18]. Their analysis of the second law of thermodynamics leads to a surprising equivalence: a moving heat bath is physically equivalent to a mixture of heat baths at rest, each with a different temperature.

The general formalism

Transition rate of a uniformly moving atom in a background thermal bath

Conclusions