Bose-Einstein Condensation and Spin Mixtures of Optically Trapped Metastable Helium

Guthrie B. Partridge (1) , Jean-Christophe Jaskula (1) , Marie Bonneau (1) , Denis Boiron (1) , Christoph I Westbrook (1)

1 laboratoire Charles Fabry de l'Institut d'Optique / Optique atomique

We report the realization of a BEC of metastable helium-4 atoms ($^4$He$^*$) in an all optical potential. Up to 10$^5$ spin polarized $^4$He$^*$ atoms are condensed in an optical dipole trap formed from a single, focused, vertically propagating far off-resonance laser beam. The vertical trap geometry is chosen to best match the resolution characteristics of a delay-line anode micro-channel plate detector capable of registering single He$^*$ atoms. We also confirm the instability of certain spin state combinations of $^4$He$^*$ to two-body inelastic processes, which necessarily affects the scope of future experiments using optically trapped spin mixtures. In order to better quantify this constraint, we measure spin state resolved two-body inelastic loss rate coefficients in the optical trap.

Mots clés: Bose Einstein condensation; optical trapping; inelastic collisions

Domaines: Physique Quantique [quant-ph]; Optique [physics.optics]

Guthrie B. Partridge, Jean-Christophe Jaskula, Marie Bonneau, Denis Boiron, Christoph I Westbrook. Bose-Einstein Condensation and Spin Mixtures of Optically Trapped Metastable Helium. Physical Review A : Atomic, molecular, and optical physics [1990-2015], 2010, 81 (5), pp.053631. ⟨10.1103/PhysRevA.81.053631⟩. ⟨hal-00467005⟩