12:QO QThF4 Mechanical effects of the resonant dipole-dipole interaction on two trapped atoms

U. Janicke, Martin Wilkens

Published Jan 1, 1995• 0 citations

Abstract

We study the mechanical impact of the emission of a photon on the center-of-mass state of two atoms in a trap. In optical diagnostics of trapped atoms, this problem is of relevance for the understanding of the back-action of photon scattering on the distribution of the atoms over the trap states. For the envisioned laser-like source of atoms (‘boser”) based on optical pumping [l], an understanding of the mechanical effects of the emitted photon is crucial as they effect strongly the small signal gain and also the atom number statistics in the “bosing” mode. For trap sizes L >> A, the resonant dipole-dipole interaction can be understood in terms of an exchange of “ballistic” photons which generally leads to heating and in 3D prevents the boser from reaching threshold [2]. For L A, the ballistic model becomes inapplicable and a refined treatment of the interaction is compulsory. We study the case of two atoms when one atom is excited initially while the other atom is in the electronic ground state. We take into account the full tensor character of the induced dipole-dipole interaction and also treat the center-of-mass motion quantum mechanically utilizing Monte-Carlo wave packet simulations [see Fig. l(left)]. We compare our findings with simplified models based on classical center-of-mass dynamics [see Fig. l(right)]. We also discuss our results with respect to the problem of small signal gain of the boser.

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