Excitation and decay of a multilevel atom

PAUL M. RADMORE

Е. Н. Попов, A. S. Kuraptsev, Igor M. Sokolov

Abstract On the basis of a consistent quantum microscopic approach, we consider the decay of a multilevel atom excited in an ensemble of resonant two-level atoms. We show that the decay rate of different Zeeman sublevels of the excited state can be different, unlike in the case of a free atom. This effect is observed even when the environment is isotropic. Furthermore, we find that different irreducible components of the density matrix of initially excited multilevel atoms also differ in terms of decay rate.

Igor I Sobel'man

Luı́s E. E. de Araujo

In this paper, I study the coherent control and suppression of the free-induction-decay emission associated with the decay from an excited multilevel atom to its ground state. It is shown here that a strong and ultrashort coupling pulse, resonant with the excited states and a lower state other than the ground state, can induce destructive quantum interferences in the decay process. The suppression is temporary and the free-induction-decay signal reappears one quantum-beat period (of the excited states) later. A sequence of equally spaced, ultrashort coupling pulses can control the moment the free-induction-decay emission occurs.

K. I. Rozgachev, V. A. Fabrikant

Asier Piñeiro Orioli, James K. Thompson, Ana María Rey

We investigate the collective decay dynamics of atoms with a generic multilevel structure (angular momenta F ↔ F 0 ) coupled to two light modes of different polarization inside a cavity.In contrast to twolevel atoms, we find that multilevel atoms can harbor eigenstates that are perfectly dark to cavity decay even within the subspace of permutationally symmetric states (collective Dicke manifold).The dark states arise from destructive interference between different internal transitions and are shown to be entangled.Remarkably, the superradiant decay of multilevel atoms can end up stuck in one of these dark states, where a macroscopic fraction of the atoms remains excited.This opens the door to the preparation of entangled dark states of matter through collective dissipation that are useful for quantum sensing and quantum simulation.Our predictions should be readily observable in current optical cavity experiments with alkaline-earth atoms or Raman-dressed transitions.