On the Bethe-Lamb equations

Willis E. Lamb, Rainer R. Schlicher, Marlan O. Scully

Almost forty years ago one of us (W.E.L.) noticed that within the analysis of experiments on the hydrogen fine structure the matter-field interaction was sensitive to the choice of gauge when decaying states were used. In the present paper this problem is resolved for the Bethe-Lamb equations in the context of the two-level model with Weisskopf-Wigner decay included.

Amnon Katz

R. Bullough, P. J. Caudrey

Reports a natural all-order decorrelation procedure for the interaction of a single two-level atom with all modes of the radiation field which replaces the semiclassical boson approximation for the atom by an exact fermion treatment. In consequence, the spontaneous emission of the semiclassical theory is extended to include stimulated emission, a semiclassical Lamb-type shift is explicitly replaced by a shift satisfying the Bethe formula manifestly due to vacuum fluctuations, and there can be two intensity-dependent terms, one of which generalizes the Bethe formula.

R. Bullough, P. J. Caudrey, A.‐S. F. Obada

A natural all-order decorrelation procedure is described for the interaction of a single two-level atom with all modes of the radiation field which replaces the semi-classical boson approximation for the atom by an exact fermion treatment. In consequence the vacuum Lamb shift appears as twice the Bethe shift for each level separately instead of the limiting neo-classical shift obtained in the Bose theory. Stimulated emission and absorption modify the Einstein A-coefficient and the vacuum shift is extended to include a field dependent shift. The all-order decorrelated perturbation theory yields an equation of motion for the single-atom dipole moment which includes those reported from operator radiation reaction theory recently; but it also generalizes these by including the effects of stimulated processes. The method is extended to a many-atom case in which it becomes necessary to modify the procedure slightly.

Yupeng Wang, Wen‐Li Yang, Junpeng Cao +1 more