Acceleration of atoms by a strong resonance field

A. P. Kazantsev

Qiulong Cheng, Zhiying Zhu

Abstract We investigate a two-level atom interacting with a massless real scalar field inside an infinitely long cylindrical cavity, and calculate separately the contributions of vacuum fluctuations and radiation reaction to the mean atomic energy-change rate when the atom moves along the cavity axis. Using the formalism suggested by Dalibard, Dupont-Roc, and Cohen-Tannoudji, we analyze both inertial and uniformly accelerated motion, and discuss the behavior in the low-acceleration and high-acceleration regimes. For the inertial atom, we further introduce a finite cavity quality factor Q to phenomenologically account for cavity dissipation, which regularizes the resonant singularity of the ideal lossless cavity and yields finite resonant peaks. For a uniformly accelerated excited-state atom in the low-acceleration regime, the energy-change rate remains finite at the nominal resonance points, but exhibits pronounced oscillatory enhancement near resonance. In certain parameter regions, the cavity result can exceed both the corresponding inertial result in the same cavity and the uniformly accelerated result in free space, revealing the combined effect of acceleration-induced broadening and the discrete transverse mode structure of the cylindrical boundary. In the high-acceleration regime, a ground-state atom may undergo spontaneous excitation, while the cavity resonance structure is strongly suppressed and the energy-change rate gradually approaches the corresponding free-space value. These results show that the cylindrical geometry can significantly reshape the radiative response of accelerated atoms, enhancing acceleration-induced effects at low acceleration while washing out cavity-induced resonances at high acceleration.

Wenting Zhou, Roberto Passante, Lucia Rizzuto

We study the resonant dipole–dipole interaction energy between two non-inertial identical atoms, one excited and the other in the ground state, prepared in a correlated Bell-type state, and interacting with the scalar field or the electromagnetic field nearby a perfectly reflecting plate. We suppose the two atoms move with the same uniform acceleration, parallel to the plane boundary, and that their separation is constant during the motion. By separating the contributions of radiation reaction field and vacuum fluctuations to the resonance energy shift of the two-atom system, we show that Unruh thermal fluctuations do not affect the resonance interaction, which is exclusively related to the radiation reaction field. However, non-thermal effects of acceleration in the radiation-reaction contribution, beyond the Unruh acceleration–temperature equivalence, affect the resonance interaction energy. By considering specific geometric configurations of the two-atom system relative to the plate, we show that the presence of the mirror significantly modifies the resonance interaction energy between the two accelerated atoms. In particular, we find that new and different features appear with respect to the case of atoms in the free-space, related to the presence of the boundary and to the peculiar structure of the quantum electromagnetic field vacuum in the locally inertial frame. Our results suggest the possibility to exploit the resonance interaction between accelerated atoms as a probe for detecting the elusive effects of atomic acceleration on radiative processes.

Sergey G. Rautian, Gennady I. Smirnov

Lucia Rizzuto, Margherita Lattuca, Jamir Marino +4 more

We study the resonance interaction between two uniformly accelerated identical atoms, one excited and the other in the ground state, prepared in a correlated (symmetric or antisymmetric) state and interacting with the scalar field or the electromagnetic field in the vacuum state. In this case (resonance interaction), the interatomic interaction is a second-order effect in the atom-field coupling. We separate the contributions of vacuum fluctuations and radiation reaction to the resonance energy shift of the system, and show that only radiation reaction contributes, while Unruh thermal fluctuations do not affect the resonance interaction. We also find that beyond a characteristic length scale related to the atomic acceleration, nonthermal effects in the radiation-reaction contribution change the distance dependence of the resonance interaction. Finally, we find that previously unidentified features appear, compared with the scalar field case, when the interaction with the electromagnetic field is considered, as a consequence of the peculiar nature of the vacuum quantum noise of the electromagnetic field in a relativistically accelerated background.

M. L. Ter-Mikaelian, M. A. Sarkissian