Suppression of Zeeman Relaxation in Cold Collisions of \(^2P_{1/2}\) Atoms

Abstract

We present a combined experimental and theoretical study of angular momentum depolarization in cold collisions of (^2P) atoms in the presence of an external magnetic field. We show that collision-induced Zeeman relaxation of Ga(^2P_{1/2}) and In (^2P_{1/2}) atoms in cold (^4)He gas is dramatically suppressed compared to atoms in (^2P_{3/2}) states. Using rigorous quantum-scattering calculations based on ab initio interaction potentials, we demonstrate that Zeeman transitions in collisions of atoms in (^2P) electronic states occur via couplings to the (^2P_{3/2}) state induced by the anisotropy of the interaction potential. Our results suggest the feasibility of sympatheticthetic cooling and magnetic trapping of (^2P_{1/2})-state atoms, such as halogens, thereby opening up exciting areas of research in precision spectroscopy and cold-controlled chemistry.