Speaker: Cleanthes A. Nicolaides Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vasileos Constantinou Avenue, Athens 11635, Greece

Title: Attosecond-resolved electron dynamics in many-electron atoms: Quantitative theory and comparison with measurements

Abstract:

A variety of processes originating from the interaction of atomic or molecular N-electron states with strong and/or hypershort radiation pulses can be understood quantitatively only by first determining with good accuracy the solutions,  Ψ(t) , of the many-electron time-dependent Schrödinger equation (METDSE) that describe the corresponding physics. The METDSE is solvable nonperturbatively via the statespecific expansion approach (SSEA), introduced in 1993-4.

The SSEA solutions have been used, or can be used, for the quantitative explanation and for numerically reliable predictions of quantities that have been measured or are measurable in modern laser-driven experiments that can track with hypershort (attosecond) time resolution the effects of electron rearrangements in atoms and molecules. The calculations take into account in a transparent way the interplay between the phenomena and the electronic structures of the physically significant states in the discrete and in the multichannel continuous spectra, including multiply- and inner-hole- excited resonance states.

The discussion will focus on the characteristics of the SSEA and on its application to the quantitative treatment of problems requiring the knowledge and use of the many-electron  Ψ(t) . The examples will include comparison of our predictions from 2007 and 2010 with recent quantitative measurements of the attosecondresolved generation of the profile of the 2s2 p ¹P^o resonance state of Helium during photoionization, and of the relative time delay in the photoemission of the (2s,2p) electrons of Neon.

C. A. Nicolaides, Resonances in the continuum, field-induced nonstationary states, and the state- and property-specific treatment of the many-electron problem, Adv. Quantum Chem. 2017,  74 , 149.

Coffee/tea and cake from 14:00