Anstract
Laser cooling relies on velocity selective optical forces to increase a gaseous atomic sample's phase space density, thereby cooling the atoms. In nearly all laser cooling schemes, both the velocity selectivity and the radiation forces are accomplished using optical transitions between atomic ground and excited states. There are, however, a class of atomic species, such as (anti)hydrogen, that are hard to be laser-cooled due to unavailability of radiation source at the required wavelengths (e.g., deep ultraviolet). In this talk I will review some of recent work on laser cooling using multi-photon and excited state transitions, which may provide an alternative route toward efficient cooling of these atomic species. The sub-Doppler cooling effect observed in this experiment will also be discussed together with recent progress on sub-Doppler cooling of K40, an important fermionic alkaline species for degenerate quantum gas researches.
Coffee and tea will be served 20 minutes prior to the seminar.