Vacuum fluctuations and radiation reaction contributions to the resonance dipole-dipole interaction between two atoms near a reflecting boundary

TL;DR

This paper analyzes how a reflecting boundary influences the resonance dipole-dipole interaction between two atoms, revealing that only radiation reaction contributes to the interaction and demonstrating boundary effects on interaction strength and spatial dependence.

Contribution

It demonstrates that vacuum fluctuations do not contribute to the resonance interaction and shows how a boundary can be used to control atomic interactions and energy transfer.

Findings

Only the source field contributes to the resonance interaction.

The boundary significantly alters the interaction's spatial dependence.

The boundary can be used to tailor atomic energy transfer processes.

Abstract

We investigate the resonance dipole-dipole interaction energy between two identical atoms, one in the ground state and the other in the excited state, interacting with the electromagnetic field in the presence of a perfectly reflecting plane boundary. The atoms are prepared in a correlated (symmetric or anti-symmetric) Bell-type state. Following a procedure due to Dalibard et. al. [J. Dalibard et. al., J. Phys. (Paris) {\bf 43}, 1617 (1982); {\bf 45}, 637 (1984)], we separate the contributions of vacuum fluctuations and radiation reaction (source) field to the resonance interaction energy between the two atoms, and show that only the source field contributes to the interatomic interaction, while vacuum field fluctuations do not. By considering specific geometric configurations of the two-atom-system with respect to the mirror and specific choices of dipole orientations, we show that the presence of the mirror significantly affects the resonance interaction energy and that different features appear with respect to the case of atoms in free space, for example a change in the spatial dependence of the interaction. Our findings also suggest that the presence of a boundary can be exploited to tailor and control the resonance interaction between two atoms, as well as the related energy transfer process. The possibility of observing these phenomena is also discussed.