title: Spin-orbit suppression of cold inelastic collisions of aluminum and helium.
abstract: We present a quantitative study of suppression of cold inelastic collisions by the spin-orbit interaction. We prepare cold ensembles of >10(11) Al(2P(1/2)) atoms via cryogenic buffer-gas cooling and use a single-beam optical pumping method to measure their magnetic (m(J)-changing) and fine-structure (J-changing) collisions with 3He atoms at millikelvin temperatures over a range of magnetic fields from 0.5 to 6 T. The experimentally determined rates are in good agreement with the functional form predicted by quantum scattering calculations using ab initio potentials. This comparison provides direct experimental evidence for a proposed model of suppressed inelasticity in collisions of atoms in 2P(1/2) states [T. V. Tscherbul et al., Phys. Rev. A 80, 040701(R) (2009)], which may allow for sympathetic cooling of other 2P(1/2) atoms (e.g., In, Tl and metastable halogens).
authors.affiliation: Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Colin Bryant
authors.initials: CB
authors.lastname: Connolly
authors.forename: Yat Shan
authors.initials: YS
authors.lastname: Au
authors.forename: Eunmi
authors.initials: E
authors.lastname: Chae
authors.forename: Timur V
authors.initials: TV
authors.lastname: Tscherbul
authors.forename: Alexei A
authors.initials: AA
authors.lastname: Buchachenko
authors.forename: Hsin-I
authors.initials: HI
authors.lastname: Lu
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Ketterle
authors.forename: John M
authors.initials: JM
authors.lastname: Doyle