Dynamics of high-angular-momentum velocity-selective coherent population trapping

Abstract

We give a systematic analysis of the extension of the one-dimensional velocity-selective coherent population trapping cooling mechanism to atoms with integer angular momenta $F>\mathrm{}1\mathrm{}$ using additional light shifts to compensate for the kinetic energy mismatch between the various Zeeman sublevels contributing to the internally decoupled (i.e., dark) state of the atom. Different configurations to achieve the proper light shifts to obtain a very long lifetime of the velocity-selective dark states are discussed and compared. In addition we show that the maximum occupation probability of the resulting quasidark state and its filling time scale strongly depend on the proper choice of detunings to exploit extra precooling mechanisms involving the Zeeman sublevels not contributing to the dark state. We show that additional cooling can also be implemented on the hyperfine repumping transition. This result should prove important for other schemes involving gray states such as, e.g., dark optical lattices and superlattices as well. As a concrete example we consider cesium including all relevant hyperfine levels.