Spontaneous Emission of an Atom Near an Oscillating Mirror

Alessandro Ferreri,Roberto Passante,Michelangelo Domina,Lucia Rizzuto

doi:10.3390/sym11111384

Alessandro Ferreri, Roberto Passante + Show 2 more

Open Access

https://doi.org/10.3390/sym11111384

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Abstract

We investigate the spontaneous emission of one atom placed near an oscillating reflecting plate. We consider the atom modeled as a two-level system, interacting with the quantum electromagnetic field in the vacuum state, in the presence of the oscillating mirror. We suppose that the plate oscillates adiabatically, so that the time-dependence of the interaction Hamiltonian is entirely enclosed in the time-dependent mode functions, satisfying the boundary conditions at the plate surface, at any given time. Using time-dependent perturbation theory, we evaluate the transition rate to the ground-state of the atom, and show that it depends on the time-dependent atom–plate distance. We also show that the presence of the oscillating mirror significantly affects the physical features of the spontaneous emission of the atom, in particular the spectrum of the emitted radiation. Specifically, we find the appearance of two symmetric lateral peaks in the spectrum, not present in the case of a static mirror, due to the modulated environment. The two lateral peaks are separated from the central peak by the modulation frequency, and we discuss the possibility to observe them with actual experimental techniques of dynamical mirrors and atomic trapping. Our results indicate that a dynamical (i.e., time-modulated) environment can give new possibilities to control and manipulate also other radiative processes of two or more atoms or molecules nearby, for example their cooperative decay or the resonant energy transfer.

Highlights

Recent advances in quantum optics techniques and atomic physics have opened new perspectives for cavity quantum electrodynamics and solid state physics, making possible engineering systems with a tunable atom-photon coupling
These findings suggested that a dynamical environment can give further possibilities to control radiative processes of atoms, which is of fundamental importance for many processes in quantum optics and its applications
We found a similar behavior of the spectrum for a two-level atom located inside a dynamical photonic crystal [40]; in that case, the two lateral peaks were strongly asymmetric due to the different density of states at the edges of the the photonic band gap

Summary

Introduction

Recent advances in quantum optics techniques and atomic physics have opened new perspectives for cavity quantum electrodynamics and solid state physics, making possible engineering systems with a tunable atom-photon coupling. The spontaneous emission rate and the emission spectrum of an atom inside a dynamical (time-modulated) photonic crystal, when its transition frequency is close to the gap of the crystal, have been recently investigated by the authors, finding modifications strictly related to the time-dependent photonic density of states [40] These findings suggested that a dynamical environment can give further possibilities to control radiative processes of atoms, which is of fundamental importance for many processes in quantum optics and its applications. In this framework, the main aim of the present paper is to investigate the effects of a different kind of dynamical (time-dependent) environment, an oscillating mirror, on the spontaneous decay of one atom in the vacuum, discussing both the decay rate and the emitted spectrum.

Spontaneous Emission Rate of One Atom near an Oscillating Mirror

Spectrum of the Radiation Emitted

Conclusions