@article{ffa70de513034b93b9e3ec9670441ac1,
title = "On the Wigner-Weisskopf approximation in quantum optics",
abstract = "In this paper, we derive the Wigner-Weisskopf approximation by the perturbation theory of Lindstedt and Poincare, and show that the approximation actually corresponds to the lowest perturbative term.",
author = "Wang, {Y. K.} and Khoo, {I. C.}",
note = "Funding Information: Weisskopf and Wigner \[1 \] established the Wigner-Weisskopf (WW) approximation in 1930 by considering the spontaneous radiation from an excited two-level atom. They assumed an exponential decay of{"} the amplitude of the excited state, and then showed that the resulting formulas are, at large time, consistent with their assumption. The approximation has since then been used by several authors \[2\] in dealing with problems in quantum optics. Recently Knight and Allen \[3\]h ave shown that it results from an exact summation of a class of Feynman diagrams. Subsequently Lee et al. \[4\]d erived the WW approximation by a multiple time scale perturbation theory of Krylov and Bogoliubov \[4\].T hey based their analysis on the fact that there are two different time scales in the problem, namely, the inverse of frequencies of the radiative transition co-1, and the inverse of the radiation linewith 3'-1. The WW approximation was deduced by taking one time scale to be infinite, while keeping the other time scale finite. In this paper, we propose another approach to the problem, that is, we shall derive the WW approxima- Research partially supported by Advanced Research Projects Agency and monitored by Office of Naval Research Contract No. N00014-67-A-0398, and by the U.S. Army Research Office (Durham). Copyright: Copyright 2015 Elsevier B.V., All rights reserved.",
year = "1974",
month = aug,
doi = "10.1016/0030-4018(74)90227-2",
language = "English (US)",
volume = "11",
pages = "323--326",
journal = "Optics Communications",
issn = "0030-4018",
publisher = "Elsevier",
number = "4",
}