Spontaneous excitation of an accelerated multilevel atom in dipole coupling to the derivative of a scalar field

TL;DR

This paper investigates how an accelerated multilevel atom interacts with a derivative-coupled scalar field, revealing acceleration-induced corrections and anisotropic effects distinct from monopole interactions.

Contribution

It introduces the analysis of an atom's spontaneous excitation with derivative coupling, highlighting new acceleration-dependent corrections and anisotropic polarization effects.

Findings

Acceleration induces corrections proportional to acceleration squared.

Anisotropic contributions from longitudinal and transverse polarizations.

Acceleration effects depend on the type of atom-field interaction.

Abstract

We study the spontaneous excitation of an accelerated multilevel atom in dipole coupling to the derivative of a massless quantum scalar field and separately calculate the contributions of the vacuum fluctuation and radiation reaction to the rate of change of the mean atomic energy of the atom. It is found that, in contrast to the case where a monopole like interaction between the atom and the field is assumed, there appear extra corrections proportional to the acceleration squared, in addition to corrections which can be viewed as a result of an ambient thermal bath at the Unruh temperature, as compared with the inertial case, and the acceleration induced correction terms show anisotropy with the contribution from longitudinal polarization being four times that from the transverse polarization for isotropically polarized accelerated atoms. Our results suggest that the effect of acceleration on the rate of change of the mean atomic energy is dependent not only on the quantum field to which the atom is coupled, but also on the type of the interaction even if the same quantum scalar field is considered.