Deep laser cooling of magnesium atoms using a 33P2→33D3 dipole transition

Abstract

We present the theoretical analysis of sub-Doppler laser cooling of 24Mg atoms using dipole transition 33P2→33D3 under two counterpropagating light waves with opposite circular polarizations (one-dimensional σ+σ– configuration). For numerical calculations the standard semi-classical approach based on the Fokker–Planck equation for linear momentum distribution of atoms is exploited. The distributions are gained beyond the limits of slow atoms approximation and for an arbitrary light field intensity. The absence of these limits allows us to determine the optimal parameters of the light field to maximize a fraction of ultracold atoms (T ~ 10 μK) in a whole atomic cloud. In particular, under certain conditions the fraction can reach a value of 50%. Solution of the existing problems in deep laser cooling of magnesium atoms has obvious prospects for atomic optics and quantum metrology: for instance, in designing new-generation optical frequency and time standards based on cold atoms in optical lattices.