Polarization Enhanced Deep Optical Dipole Trapping of Λ -Cooled Polar Molecules
Thomas Langin, Varun Jorapur, Yuqi Zhu +2 more
We demonstrate loading of SrF molecules into an optical dipole trap (ODT) via in-trap $\mathrm{\ensuremath{\Lambda}}$-enhanced gray molasses cooling. We find that this cooling can be optimized by a proper choice of relative ODT and cooling beam polarizations. In this optimized configuration, we observe molecules with temperatures as low as $14(1)\text{ }\text{ }\ensuremath{\mu}\mathrm{K}$ in traps with depths up to $570\text{ }\text{ }\ensuremath{\mu}\mathrm{K}$. With optimized parameters, we transfer $\ensuremath{\sim}5%$ of molecules from our radio-frequency magneto-optical trap into the ODT, at a density of $\ensuremath{\sim}2\ifmmode\times\else\texttimes\fi{}{10}^{9}\text{ }\text{ }{\mathrm{cm}}^{\ensuremath{-}3}$, a phase space density of $\ensuremath{\sim}2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}7}$, and with a trap lifetime of $\ensuremath{\sim}1\text{ }\text{ }\mathrm{s}$.
arXiv:2106.00622•Physical Review Letters•Oct 12, 2021•45 citations