Quantum Theory of a Damped Two-Level Atom

Abstract

The interaction of a two-level atom with the radiation field in a cavity is discussed in quantum mechanical terms that are closely analogous to those used in discussing the classical Langevin equation; the quantum Langevin equation for this case, however, is nonlinear. A technique is developed for finding the measurable properties of the solution of the equations exactly; the properties of the solution are compared with those for the harmonic oscillator.