Sudden perturbation approximations for interaction of atoms with intense ultrashort electromagnetic pulses
© 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...
| Main Authors: | , |
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| Format: | Journal Article |
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2015
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| Online Access: | http://hdl.handle.net/20.500.11937/13771 |
| _version_ | 1848748435213123584 |
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| author | Lugovskoy, Andrey Bray, I. |
| author_facet | Lugovskoy, Andrey Bray, I. |
| author_sort | Lugovskoy, Andrey |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | © 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. |
| first_indexed | 2025-11-14T07:05:00Z |
| format | Journal Article |
| id | curtin-20.500.11937-13771 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T07:05:00Z |
| publishDate | 2015 |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-137712017-09-13T15:00:25Z Sudden perturbation approximations for interaction of atoms with intense ultrashort electromagnetic pulses Lugovskoy, Andrey Bray, I. © 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. 2015 Journal Article http://hdl.handle.net/20.500.11937/13771 10.1140/epjd/e2015-60471-2 restricted |
| spellingShingle | Lugovskoy, Andrey Bray, I. Sudden perturbation approximations for interaction of atoms with intense ultrashort electromagnetic pulses |
| title | Sudden perturbation approximations for interaction of atoms with intense ultrashort electromagnetic pulses |
| title_full | Sudden perturbation approximations for interaction of atoms with intense ultrashort electromagnetic pulses |
| title_fullStr | Sudden perturbation approximations for interaction of atoms with intense ultrashort electromagnetic pulses |
| title_full_unstemmed | Sudden perturbation approximations for interaction of atoms with intense ultrashort electromagnetic pulses |
| title_short | Sudden perturbation approximations for interaction of atoms with intense ultrashort electromagnetic pulses |
| title_sort | sudden perturbation approximations for interaction of atoms with intense ultrashort electromagnetic pulses |
| url | http://hdl.handle.net/20.500.11937/13771 |