Subrecoil laser cooling with adiabatic transfer

We demonstrate subrecoil cooling of rubidium atoms by velocity-selective coherent population trapping. By adiabatic transfer of the cooled atoms into a spin polarized single momentum state we show the coherence of the trapped state. Our cooling scheme takes advantage of the rubidium hyperfine structure to integrate subrecoil and sub-Droppler cooling. Starting from an initial velocity distribution of twice the recoil temperature [T-rec = (HBARk)(2)/k(B)M], we cool down to 100 nK (approximate to 1/3T(rec)) within 1 ms, while almost completely suppressing the diffusive heating of velocity-selective coherent population trapping.