Cooling of multilevel atoms below the one-photon recoil limit by Raman π-pulses

Abstract

Analysis of optical excitation of a double Λ system with three lower and two excited states (so-called M atom) by the field of four travelling optical waves is carried out. It is shown that excitation of such a system by Raman π pulses can be used for deep cooling of M atoms to a temperature much lower than the temperature controlled by the recoil energy. The application of the proposed scheme considerably simplifies practical implementation of deep Raman cooling, which considerably extends the range of application of this technique.