Application of the Projection Technique to Two-Level Atoms
A. Muriel · Physical Review A · 1971
Exact, formal, and usable solutions of the Liouville equation corresponding to the problem of independent two-level atoms in an external field are presented. Two examples are worked out: calculation of the polarization, and a model of pumping or population inversion by a $\ensuremath{\delta}$-function external field. The relation of the solutions to other problems in statistical mechanics is also discussed.