Time-dependent formation of the profile of the He 2s2p Po1 state excited by a short laser pulse

Mercouris, Th; Komninos, Y; Nicolaides, CA

dc.contributor.author	Mercouris, Th	en
dc.contributor.author	Komninos, Y	en
dc.contributor.author	Nicolaides, CA	en
dc.date.accessioned	2014-03-01T01:27:29Z
dc.date.available	2014-03-01T01:27:29Z
dc.date.issued	2007	en
dc.identifier.issn	1050-2947	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/18468
dc.subject.classification	Optics	en
dc.subject.classification	Physics, Atomic, Molecular & Chemical	en
dc.subject.other	Crystal atomic structure	en
dc.subject.other	Electric excitation	en
dc.subject.other	Helium	en
dc.subject.other	Ionization	en
dc.subject.other	Codling	en
dc.subject.other	Differential ionization probability	en
dc.subject.other	Fano asymmetry parameter	en
dc.subject.other	Photoabsorption measurements	en
dc.subject.other	Ultrashort pulses	en
dc.title	Time-dependent formation of the profile of the He 2s2p Po1 state excited by a short laser pulse	en
heal.type	journalArticle	en
heal.identifier.primary	10.1103/PhysRevA.75.013407	en
heal.identifier.secondary	http://dx.doi.org/10.1103/PhysRevA.75.013407	en
heal.identifier.secondary	013407	en
heal.language	English	en
heal.publicationDate	2007	en
heal.abstract	We produce quantitatively accurate data for the energy- and time-dependent formation of the profile of the differential ionization probability of the He 1 s2 S1 ground state from the coherent excitation and decay of the doubly excited He 2s2p Po1 resonance state induced by a pulse of duration of 450 a.u. and field strength in the range F=0.4× 10-3 a.u. to F=0.4× 10-1 a.u. Two general methods were applied. One is analytic, using Fano's configuration interaction in the continuum in the framework of first order time-dependent perturbation theory. The other is numerical, using the state-specific expansion approach for the nonperturbative solution of the time-dependent Schrödinger equation. Electronic structures and electron correlation are incorporated via the use of state-specific wave functions for the initial state, the resonance state, and the continuum of scattering states. The results from the two methods are in perfect agreement, with a small discrepancy starting at F=0.4× 10-1 a.u. The weak field analytic formulas show explicitly the dependence of the profile formation on the pulse characteristics. In the limit of large times, the system becomes stationary and the computed resonance state profile yields the Fano asymmetry parameter of q=-2.8, with energy Er =60.20 eV and width Γ=0.038 eV. These values agree with previously published ones obtained from time-independent calculations and from photoabsorption measurements of the type initiated by Madden and Codling in 1963. © 2007 The American Physical Society.	en
heal.publisher	AMERICAN PHYSICAL SOC	en
heal.journalName	Physical Review A - Atomic, Molecular, and Optical Physics	en
dc.identifier.doi	10.1103/PhysRevA.75.013407	en
dc.identifier.isi	ISI:000243894100109	en
dc.identifier.volume	75	en
dc.identifier.issue	1	en