Theory and computation of the matrix elements of the full interaction of the electromagnetic field with an atomic state: Application to the Rydberg and the continuous spectrum

Komninos, Y; Mercouris, T; Nicolaides, CA

dc.contributor.author	Komninos, Y	en
dc.contributor.author	Mercouris, T	en
dc.contributor.author	Nicolaides, CA	en
dc.date.accessioned	2014-03-01T01:52:13Z
dc.date.available	2014-03-01T01:52:13Z
dc.date.issued	2002	en
dc.identifier.issn	1050-2947	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/26602
dc.subject.classification	Optics	en
dc.subject.classification	Physics, Atomic, Molecular & Chemical	en
dc.subject.other	RESONANT QUANTUM COHERENCE	en
dc.subject.other	PHOTOEXCITATION	en
dc.subject.other	SUPPRESSION	en
dc.title	Theory and computation of the matrix elements of the full interaction of the electromagnetic field with an atomic state: Application to the Rydberg and the continuous spectrum	en
heal.type	journalArticle	en
heal.identifier.secondary	043412	en
heal.language	English	en
heal.publicationDate	2002	en
heal.abstract	We develop practical formulas for the calculation of the matrix elements of the interaction of the electromagnetic field with an atomic state, beyond the long-wavelength approximation. The atom-plus-field Hamiltonian is chosen to have the multipolar form, containing the electric, paramagnetic, and diamagnetic operators. The final workable expressions include the interactions to all orders and are derived by first expanding the fields in partial waves. The electric-field operator reaches a constant value as the radial variable becomes large, contrary to the result of the electric-dipole approximation (EDA) where the value of the corresponding operator increases indefinitely. Applications are given for Rydberg states of hydrogen up to n=50 and for free-free transitions in a Coulomb potential. Such matrix elements are relevant to a number of real and virtual processes occurring during laser-atom interactions. The computation is done numerically, using a combination of analytic with numerical techniques. By comparing the results of the EDA with those of the exact treatment, it is shown that the former is inadequate in such cases. This finding has repercussions on the theory and understanding of the physics of quantum systems in high-lying Rydberg levels and wave packets or in scattering states.	en
heal.publisher	AMERICAN PHYSICAL SOC	en
heal.journalName	PHYSICAL REVIEW A	en
dc.identifier.isi	ISI:000174979100018	en
dc.identifier.volume	65	en
dc.identifier.issue	4	en