Sudden perturbation approximations for interaction of atoms with intense ultrashort electromagnetic pulses
MetadataShow full item record
© 2015 EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg. The response of an atom to the action of a pulse shorter than the Kepler period of the optically-active electron is often treated analytically using the sudden-perturbation approximation (SPA). It relies on the truncation of the evolution operator expansion in a series over the dimensionless parameter e sys t L, where e sys is the system-dependent characteristic energy and t L is the pulse duration. We examine the SPA with the use of a basis-based solution of the time-dependent Schrödinger equation (TDSE) for the case of a hydrogen atom interacting with two different types of ultrashort pulses, a half-cycle pulse and a few-cycle pulse. The length-gauge form of the electron-field interaction potential is used. The SPA transition probabilities are shown to deviate slightly but systematically from the correct values for the positive-energy states in the region where the sudden-perturbation condition is violated. It is shown that the SPA expectation value of the electron displacement as a function of time differ qualitatively from what follows from the ab initio TDSE solution. Nevertheless, the SPA is shown to be a good approximation for the description of the expectation value of the electron momentum.
Showing items related by title, author, creator and subject.
Chandratilleke, Tilak; Rakshit, D. (2013)This paper presents an investigation on the operational characteristics and thermal effectiveness of a pulsed (or synthetic) jet mechanism that periodically cools at a heated surface while acting in cross-flow fluid stream. ...
McFadden, R.; Ekers, Ronald; Bray, J. (2011)Lunar Cherenkov experiments aim to detect nanosecond pulses of Cherenkov emission produced during UHE cosmic ray or neutrino interactions in the lunar regolith. Pulses from these interactions are dispersed, and therefore ...
Lynch, Christene; Mutel, R.; Güdel, M. (2015)A number of radio-loud ultra-cool dwarf (UCD ) stars exhibit both continuous broadband and highly polarized pulsed radio emission. In order to determine the nature of the emission and the physical characteristics in the ...