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.