CORRELATION-FUNCTION APPROACH TO THE MOMENTUM DIFFUSION OF ATOMS MOVING IN STANDING WAVES

We consider the momentum diffusion of atoms moving in a standing-wave laser field. We show how the correlation-function approach as original ly applied to atoms at rest can be generalized to derive the velocity dependence of the momentum diffusion coefficient in standing waves, an d that it gives results in agreement with the transport-equation appro ach to laser cooling. As an example we apply our calculations to deter mine the achievements of laser cooling in intense fields where cooling may occur around a nonvanishing velocity. Here we obtain temperatures which are 30% lower than the corresponding minimum obtained around ze ro velocity. Our explicit calculations involve usage of the optical Bl och equations, the quantum regression theorem, and the matrix continue d-fraction method.