Coherent Manipulation of Atomic Wave Packets by Adiabatic Transfer

Abstract
We use laser induced adiabatic passage to coherently manipulate the atomic wave packets resulting from subrecoil laser cooling in one, two, and three dimensions by velocity selective coherent population trapping. Using metastable helium atoms, we demonstrate adiabatic transfer into a single wave packet or into two coherent wave packets, while retaining the subrecoil momentum dispersion of the initial wave packets. The efficiency of the transfer is nearly perfect in one and two dimensions, and of the order of 75% in three dimensions. To a large extent, the direction of the momentum and the internal state of the atoms described by each of the final wave packets can be chosen at will.