A comparison of quantum and semi-classical theories of the interaction between a two-level atom and the radiation field

Abstract

The interaction of a two-level atom with a single mode of the radiation field is considered both in a fully quantized and a semi-classical theory. With only the dipole and rotating-wave approximations the Liouville equations are solved to give the exact behaviour of the diagonal elements of the density operator and of their semi-classical analogue. The results suggest experimentally verifiable differences between the two theories.