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Physical Review A

Two-color laser cooling for K40−Rb87 quantum gas mixtures

Yann Kiefer, Max Hachmann, Andreas Hemmerich

Published Feb 14, 2024• 0 citations
Publisher

Abstract

We present an efficient cooling scheme for fermionic $^{40}\mathrm{K}$ atoms, using laser light red and blue detuned with respect to the D2 and D1 principle fluorescence lines, respectively. The cooling scheme is found to significantly increase the saturation level for loading of a $^{40}\mathrm{K}$ magneto-optical trap (MOT), resulting in increased atom numbers or decreased cycle times. While the attainable $^{40}\mathrm{K}$ atom number is approximately doubled if exclusively $^{40}\mathrm{K}$ atoms are cooled, the scheme is particularly powerful for dual-species MOTs, for example, if $^{40}\mathrm{K}$ and $^{87}\mathrm{Rb}$ atoms are cooled simultaneously in the same MOT configuration. The typical atom losses due to light-assisted heteronuclear collisions between $^{40}\mathrm{K}$ and $^{87}\mathrm{Rb}$ seem to be reduced, giving rise to a threefold improvement of the $^{40}\mathrm{K}$ atom number as compared to that in a conventional dual-species MOT, operating merely with D2 light. Our scheme can be a useful extension to most dual-species experiments, aiming to reach simultaneous degeneracy of both species.

DOI
10.1103/physreva.109.023320

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