Optical trapping of fermionic /sup 40/K atoms

Summary form only only given. We report on trapping of /sup 40/K atoms at low temperatures and high densities in a far-detuned optical trap. The trap is a vertical standing-wave created with about 550 mW of radiation tuned 10 nm on the red of the D/sub 2/ transition, and is loaded from a sample held in a magneto optical trap (MOT) at sub-Doppler temperatures, with the help of a temporal dark-spot phase and a magnetic compression phase. We are able to trap as many as 5/spl times/10/sup 6/ atoms with a lifetime of 200 ms in the F=9/2 ground state. From the temperature of the trapped atoms, which is around 30 /spl mu/K, and the measured trap frequencies (1 kHz radial, 500 kHz axial) we estimate a density of 5/spl times/10/sup 12/ cm/sup -3/.