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arXiv:1905.03555 · Physical Review A

Rapid production of large Li7 Bose-Einstein condensates using D1 gray molasses

Kyungtae Kim, SeungJung Huh, Kiryang Kwon, Jae-yoon Choi

Published May 8, 2019• 9 citations
arXivHTMLPDF

Abstract

We demonstrate the production of large $^{7}\mathrm{Li}$ Bose-Einstein condensates in an optical dipole trap using ${D}_{1}$ gray molasses. The sub-Doppler cooling technique reduces the temperature of $4\ifmmode\times\else\texttimes\fi{}{10}^{9}$ atoms to $25\phantom{\rule{0.28em}{0ex}}\ensuremath{\mu}\mathrm{K}$ in 3 ms. After microwave evaporation cooling in a magnetic quadrupole trap, we transfer the atoms to a crossed optical dipole trap, where we employ a magnetic Feshbach resonance on the $|F=1,{m}_{F}=1\ensuremath{\rangle}$ state. Fast evaporation cooling is achieved by tilting the optical potential using a magnetic field gradient on the top of the Feshbach field. Our setup produces pure condensates with $2.7\ifmmode\times\else\texttimes\fi{}{10}^{6}$ atoms in the optical potential for every 11 s. The trap tilt evaporation allows rapid thermal quench, and spontaneous vortices are observed in the condensates as a result of the Kibble-Zurek mechanism.

DOI
10.1103/physreva.99.053604

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