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

Abstract: We report a new apparatus for the study of two-species quantum degenerate mixture of $<sup>{41}$K and $<sup>6$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 $<sup>{41}$K atoms while the $<sup>6$Li atoms are sympathetically cooled in an optically-plugged magnetic trap. Finally, we achieve the simultaneous quantum degeneracy for the $<sup>{41}$K and $<sup>6$Li atoms. The Bose-Einstein condensate of $<sup>{41}$K has 1.4$\times$10$<sup>5$ atoms with a condensate fraction of about 62%, while the degenerate Fermi gas of $<sup>6$Li has a total atom number of 5.4$\times$10$<sup>5$ at 0.25 Fermi temperature.