Spontaneous recoil effects of optical pumping on trapped atoms

TL;DR

This paper provides an exact calculation of recoil effects during optical pumping of trapped atoms, revealing non-Gaussian recoil distributions and conditions for optimal quantum state protection.

Contribution

It introduces a precise, non-approximate analysis of recoil effects considering arbitrary laser parameters, advancing understanding of atomic motion during optical pumping.

Findings

Recoil shift density is non-Gaussian and anisotropic.

Isotropic recoil distribution occurs only at specific fluorescence conditions.

Optimal parameters depend on the property to be protected from disturbance.

Abstract

The recoil effects of spontaneous photon emissions during optical pumping of a trapped three-level atom are exactly calculated. Without resort to the Lamb-Dicke approximation, and considering arbitrary detuning and saturation of the pump laser, the density of recoil shifts in phase space is derived. It is shown that this density is not of Gaussian shape, and that it becomes isotropic in phase space only for a branching ratio corresponding to fluorescence scattering but unfavorable for optical pumping. The dependence of its anisotropy on the laser saturation is discussed in the resonant case, and the mapping of moments of the atom's center-of-mass motion due to the pumping is presented. Moreover, it is shown how optimum parameters for protecting the center-of-mass quantum state from pump-induced disturbance depend on the specific property to be protected.