Interaction of Atoms in the Approximation of Depolarizing Collisions

E. Duman

E. E. Nikitin, Anatoly I. Burshtein

E. E. Nikitin

Igor V. Yevseyev, Valery M. Yermachenko, Самарцев Виталий Владимирович

The effect of atomic collisions on the optical characteristics of an ensemble of excited atoms is well known [ 1 , 2 ]. The evolution of laser techniques and the resulting interest in various nonlinear-spectroscopy methods have suggested that atomic collisions have a significant effect on the lasing mode of gas lasers and the shape and width of various nonlinear signals. For a long time attention has been focused on the important role of elastic collisions, among other things, and various methods have been proposed for describing such collisions [ 3 ].

H. R. Sadeghpour

Mechanisms of spin depolarization, spin relaxation and spin exchange in cold atom-atom, atom-molecule collisions are discussed. The formation of weakly-bound van der Waals molecules in buffer-gas cooled magnetic traps, intermediated by anisotropic hyperfine interaction is considered.

Timur V. Tscherbul, P Zhang, H. R. Sadeghpour +1 more

Collisions of atoms and molecules in external electromagnetic fields can depolarize electronic and nuclear spins, leading to decoherence of quantum superposition states. The fundamental microscopic processes giving rise to spin depolarization are spin exchange and spin relaxation. In this work, we present an analysis of spin exchange transitions in collision of alkali metal atoms with 3He. We use accurate ab initio calculations to evaluate the electron spin density of Li-He and the interaction energy of Rb-He. The Fermi contact interaction constants for the complexes of Na, K, and Rb atoms with 3He are extracted from the measured frequency shift enhancement factors using the ab initio interaction potentials. The spin density calculations also yield the hyperfine pressure shift of Li-He.