Dressed-atom description of the bichromatic force

A dressed-atom picture of the bichromatic force in one dimension was developed using a Floquet Hamiltonian whose fundamental time variation is the beat frequency between the two optical fields. The atomic motion through the light-shift potentials and the limitations to the velocity range of the force that arise from non adiabatic transitions among the Floquet states. It was found that the bichromatic force has a magnitude larger than the radiative force, almost by the ratio and could be ∼ 100. The force was mediated by Landau-Zener transitions between the dressed states of the Floquet Hamiltonian.