Improving the formation of $^{23}$Na$^{40}$K molecules towards degeneracy

Recently L. De Marco et al. demonstrated the formation of degenerate samples of dipolar KRb molecules [1]. Inspired by this achievement we investigated molecule formation in a double-degenerate mixture of $^{23}$Na and $^{40}$K atoms. By switching from RF association to a magnetic-field sweep over a Feshbach resonance, we can now convert 50% of our Na atoms into NaK molecules and produce samples of up to $5 \times 10^4$ molecules. [1] L. De Marco et al., Science 363, 853 (2019).