COUNTERROTATING TERMS AND THE ROTATING WAVE APPROXIMATION IN MINIMALLY COUPLED MULTILEVEL SYSTEMS

A Hamiltonian theory is constructed for two minimally coupled quantum systems, which are defined as generalised oscillators in terms of arbi trary numbers of equally spaced eigenenergy levels. The corrections to the rotating wave approximation are determined by eliminating the cou nterrotating interactions from the total Hamiltonian, by means of a su itable unitary transformation. The theory is able to mimic the special cases of the interaction of an N-level atom with linearly polarised r adiation, or a two-level atom with circularly polarised radiation. The significance of the theory is discussed in relation to Hamiltonians o f the Jaynes-Cummings' type and to non-inertial photon detectors. (C) 1994 Academic Press, Inc.