Resonance interaction energy between two accelerated identical atoms in a coaccelerated frame and the Unruh effect

TL;DR

This paper studies the resonance interaction energy between two uniformly accelerated atoms in a coaccelerated frame, showing that radiation reaction, not Unruh thermal fluctuations, governs the interaction, and demonstrating frame equivalence without assuming Unruh temperature.

Contribution

It reveals that resonance interaction is unaffected by Unruh thermal fluctuations and can be analyzed in a coaccelerated frame without assuming Unruh temperature, confirming frame equivalence.

Findings

Resonance interaction is solely due to radiation reaction.

Unruh thermal fluctuations do not influence the resonance energy.

Resonance interaction in coaccelerated and inertial frames are equivalent.

Abstract

We investigate the resonance interaction energy between two uniformly accelerated identical atoms, interacting with the scalar field or the electromagnetic field in the vacuum state, in the reference frame coaccelerating with the atoms. We assume that one atom is excited and the other in the ground state, and that they are prepared in their correlated symmetric or antisymmetric state. Using perturbation theory, we separate, at the second order in the atom-field coupling, the contributions of vacuum fluctuations and radiation reaction field to the energy shift of the interacting system. We show that only the radiation reaction term contributes to the resonance interaction between the two atoms, while Unruh thermal fluctuations, related to the vacuum fluctuations contribution, do not affect the resonance interatomic interaction. We also show that the resonance interaction between two uniformly accelerated atoms, recently investigated in the comoving (locally inertial) frame, can be recovered in the coaccelerated frame, without the additional assumption of the Fulling-Davies-Unruh temperature for the quantum fields (as necessary for the Lamb-shift, for example). This indicates, in the case considered, the equivalence between the coaccelerated frame and the locally inertial frame.