报告题目：Ab-initio solution of TDSE of atoms and molecules in strong laser fields

报告时间：2015年7月21日（星期二）16:00

报告地点：理学院报告厅

报告人：Lampros Nikolopoulos，Dublin City University

报告内容：

We present a theoretical framework for the solution of the time-dependent Schrödinger equation (TDSE) of atomic systems under strong electromagnetic fields with the configuration space of the electron's coordinates confined in a finite region (I). In this region the solution of the TDSE is obtained by an eigenstate basis set representation (solution of the field-free Hamiltonian) of the time-dependent wavefunction. After having calculated the system's eigenstates (bound and continuum) on a set of B-splines basis set, a high-order propagation scheme is employed for the time propagation of the TDSE. While, in a purely hydrogenic system no approximation is involved, apart the numerical ones, a straightforward extension of the method in multielectron systems (i.e. Ne, Ar, Xe,..) the validity and the usefulness of the present method relies on the fundamental assumption of the single-active-electron approximation (SAE), namely, that only one of the valence electrons is optically active and therefore evolves effectively as a one-electron system.

The method is applied to the case of the hydrogen being the ideal system for all the unnecessary multi-electron complications to be absent. Extension of the method, based on the SAE approxi- mation, is also discussed. Ionization yields, kinetic energy and angular distributions of the ejected electron for particular cases are presented.

附.报告人简介：

Dr. Lampros Nikolopoulo's research area of interest is the Theoretical Atomic and Optical Physics with emphasis in ab-initio computation of strong laser-atom/molecules interactions. Dr Nikolopoulos got his PhD in Univ. of Crete (Physics), Greece and his research carreer include posts in Max-Planck Institute for Quantum Optics (MPQ), Univ of Aarhus Denmark and Queen's Univ. of Belfast, UK, while since 2009 holds a Lecturer position in Dublin City University (Ireland) at the School of Physical Sciences. A particular feature of his research in atomic/molecular physics is in developing and implementing high-performance computational algorithms for the calculation of complex atomic and molecular structures and the direct solution of the time-dependent Schrodinger Equation (TDSE) of complex structures in strong laser fields. Most recently Dr Nikolopoulos has also focused on the development of computational codes using general-purpose graphics processing cards (GPGPU). His collaborations over the year include theoretical and experimental groups worldwide on areas such as ultrafast multiphoton processes, atomic structure calculations, time-dependent R-matrix methods, stochastic differential equations as well as the metrology and characterization of attosecond pulses and free-electron laser studies).