Improved magneto-optical trapping of a diatomic molecule

Abstract

We present experimental results from a new scheme for magneto-optically trapping strontium monofluoride (SrF) molecules, which provides increased confinement compared to our original work. The improved trap employs a new approach to magneto-optical trapping presented by M. Tarbutt, \emph{arXiv preprint} 1409.0244, which provided insight for the first time into the source of the restoring force in magneto-optical traps (MOTs) where the cycling transition includes dark Zeeman sublevels (known as type-II MOTs). We measure a radial spring constant $20\times$ greater than in our original work with SrF, comparable to the spring constants reported in atomic type-II MOTs. We achieve a trap lifetime ${\tau }_{\mathrm{MOT}}=136(2)$~ms, over $2\times$ longer than originally reported for SrF. Finally, we demonstrate further cooling of the trapped molecules by briefly increasing the trapping lasers' detunings. Our trapping scheme remains a straightforward extension of atomic techniques and marks a step towards the direct production of large, dense, ultracold molecular gases via laser cooling.

18 pages, 6 figures

References in corpus (5)

• A High Phase-Space-Density Gas of Polar Molecules
• Magneto-optical trapping of a diatomic molecule
• Magneto-Optical Trap for Polar Molecules
• Ultracold molecules: new probes on the variation of fundamental constants
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Cited by in corpus (14)

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• Laser cooling of molecules
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• Characteristics of a magneto-optical trap of molecules
• Three-dimensional Doppler, polarization-gradient, and magneto-optical forces for atoms and molecules with dark states
• Adimensional theory of shielding in ultracold collisions of dipolar rotors
• Prospects for a Narrow Line MOT in YO
• Principles and design of a Zeeman-Sisyphus decelerator for molecular beams
• A Blue-Detuned Magneto-Optical Trap of CaF Molecules
• One dimensional magneto-optical compression of a cold CaF molecular beam
• Fast optical transport of ultracold molecules over long distances
• Multivalent optical cycling centers in polyatomic molecules
• Laser cooling of molecules
• The Li + CaF $\to$ Ca + LiF chemical reaction under cold conditions