A quantum degenerate Bose-Fermi mixture of $^{41}$K and $^6$Li

TL;DR

This paper presents a new experimental setup for creating a quantum degenerate mixture of $^{41}$K Bose-Einstein condensate and $^{6}$Li Fermi gas, demonstrating advanced cooling and transfer techniques.

Contribution

The authors develop a comprehensive apparatus combining advanced cooling, magnetic transport, and sympathetic cooling to achieve simultaneous quantum degeneracy of $^{41}$K and $^{6}$Li atoms.

Findings

Achieved Bose-Einstein condensate of $^{41}$K with 1.4×10^5 atoms

Realized degenerate Fermi gas of $^{6}$Li with 5.4×10^5 atoms

Successfully combined cooling and transfer techniques for two-species quantum gases

Abstract

We report a new apparatus for the study of two-species quantum degenerate mixture of $^{41}$K and $^6$Li atoms. We develop and combine several advanced cooling techniques to achieve both large atom number and high phase space density of the two-species atom clouds. Furthermore, we build a high-efficiency two-species magnetic transport system to transfer atom clouds from the 3D magneto-optical-trap chamber to a full glass science chamber of extreme high vacuum environment and good optical access. We perform a forced radio-frequency evaporative cooling for $^{41}$K atoms while the $^6$Li atoms are sympathetically cooled in an optically-plugged magnetic trap. Finally, we achieve the simultaneous quantum degeneracy for the $^{41}$K and $^6$Li atoms. The Bose-Einstein condensate of $^{41}$K has 1.4$\times$10$^5$ atoms with a condensate fraction of about 62%, while the degenerate Fermi gas of $^6$Li has a total atom number of 5.4$\times$10$^5$ at 0.25 Fermi temperature.