A New Projection-Operator Method for Treating Interactions of Atoms with Radiation Field

T. H. Cheung

Oleg N. Gadomsky, Konstantin V. Krutitsky

A new integro-differential operator equation which describes the propagation of a quantized radiation field in a resonant medium is obtained. We have investigated a system of atoms on the basis of the interaction of H-like atoms through the field of virtual photons, taking into account electronic and positronic intermediate states in the atomic spectrum. This interaction is treated as a third-order effect in quantum electrodynamics. We suggest a new method to solve boundary-value problems in quantum optics which employs the joint system of material and field equations.

S. Bose, David T. Ng

JOSIP SEKE

It is shown that the application of a self-consistent projection-operator method, developed recently by the author, makes a complete treatment of the spontaneously decaying atomic state in relativistic QED possible. In a new physical real-transition interaction picture (in which the unobservable interaction of the free electron with the vacuum radiation field is eliminated) explicit finite analytic results for the non-Markovian time evolution and the radiative line shape in the case of relativistic Lyman-α spontaneous emission are obtained.

Zu-Cheng Chen, Helen S. Freedhoff

The authors utilize Liouville-space and projection operator methods, introducing additional atomic projection operators, and derive master equations for an atom coupled to a radiation reservoir and to an additional external field via multi-photon interactions; the explicit forms of the equations are studied in detail for two-photon processes. The coupling coefficients of the equations are expressed in terms of effective operators for two-photon transitions. The expressions for the probability of transfer of coherence via two-photon transitions and for the dephasing due to elastic interactions with the reservoir are obtained quantum mechanically for the first time.