Cooling Below the Doppler Limit

Abstract

In response to the surprising measurements of temperatures below T _D , two groups developed a model of laser cooling that could explain the lower temperatures [83, 84]. The key feature of this model that distinguishes it from the earlier picture was the inclusion of the multiplicity of sublevels that make up an atomic state (e.g., Zeeman and hfs). The dynamics of optically pumping atoms among these sublevels provides the new mechanism for producing the ultra-low temperatures [81].