Feshbach resonances in mixtures of 6Li and 40K

We report on the measurement of Feshbach resonances in Fermi-Fermi mixtures. For this purpose we have created an ultracold mixture of the fermionic alkali isotopes 6Li and 40K in an optical dipole trap. In the same trap we have realized a three-component degenerate spin mixture of 40K -atoms at T 0.3TF. To create the mixture we start by loading a two-species magneto-optical trap (MOT) from two separate 2D-MOT sources. We realized for the first time a 2D-MOT source for lithium, yielding a large cold flux of up to 109 s-1. The mixture is then captured in an optically-plugged magnetic quadrupole trap. After sympathetic cooling of 6Li by 40K to T∝10μK the mixture is loaded into optical tweezers. The mixture is optically transported over a distance of 21.5 cm into a science cell where we measure Feshbach resonances using magnetic field coils designed for high homogeneity. We report on our progress measuring the width of Feshbach resonances in 6Li -40K mixtures and locating resonances in mixtures of 40K.