Interspecies collision-induced losses in a dual species⁷Li–⁸⁵Rb magneto-optical trap

Abstract

In this article, we report the measurement of collision-induced loss rate coefficients , Li Rb  and , Rb Li  , and also discuss means to significantly suppress such collision induced losses. We first describe our dual-species magneto-optical trap (MOT) that allows us to simultaneously trap ≥ 5×10 8 7 Li atoms loaded from a Zeeman slower and ≥ 2×10 8 85 Rb atoms loaded from a dispenser. We observe strong interspecies collision-induced losses in the MOTs which dramatically reduce the maximum atom number achievable in the MOTs. We measure the trap loss rate coefficients , Li Rb and , Rb Li  , and, from a study of their dependence on the MOT parameters, determine the cause for the losses observed. Our results provide valuable insights into ultracold collisions between 7 Li and 85 Rb, guide our efforts to suppress collision induced losses, and also pave the way for the production of ultracold 7 Li 85 Rb molecules. DOI:PACS number(s): 34.50.-s, 37.10.De

Formation of ultracold 7Li85Rb molecules in the lowest triplet electronic state by photoassociation and their detection by ionization spectroscopy

“…We use a dark spot Rb MOT to reduce collisional losses in the trap [21], leaving most of the trapped 85 Rb atoms in the F = 2 ground hyperfine level. We monitor the MOT operation and the overlap of the Li and Rb atomic clouds with a 4 pair of CCD cameras.…”

Formation of ultracold LiRb molecules by photoassociation near the Li(2 s 2 S 1/2 ) + Rb(5 p 2 P 1/2 ) asymptote

“…The fluorescence from both MOTs is collected using a lens, separated using a dichroic mirror and recorded on two separate photodiodes. More details of our dual species apparatus are described elsewhere [30].…”

Two-photon photoassociation spectroscopy of an ultracold heteronuclear molecule

“…We also report the binding energies for previously unobserved, loosely bound levels of 7 The experiment is performed in a dual-species magnetooptical trap (MOT) apparatus for simultaneous cooling and trapping of 7 Li and 85 Rb atoms, the details of which are described elsewhere [35,36]. The 85 Rb MOT is operated as a dark spot MOT in order to reduce atom loss by light assisted collisions [35,36] and to optically pump 85 Rb atoms to the 5s 2 S 1/2 (F = 2) state.…”

“…The implication of this observation on direct atom to molecule conversion using stimulated Raman adiabatic passage (STIRAP) is discussed and the prospect for electronic ground state molecule production is theoretically analyzed. The experiment is performed in a dual-species magnetooptical trap (MOT) apparatus for simultaneous cooling and trapping of 7 Li and 85 Rb atoms, the details of which are described elsewhere [35,36]. The 85 Rb MOT is operated as a dark spot MOT in order to reduce atom loss by light assisted collisions [35,36] and to optically pump 85 Rb atoms to the 5s 2 S 1/2 (F = 2) state.…”