| 报告题目： |
Ionization of rotating orbitals of atoms and molecules by strong rotating laser fields |
| 报告人： |
Ingo Barth |
| 报告人单位： |
德国马普所微结构所 |
| 报告时间： |
6月29号上午10点 |
| 报告地点： |
科技楼南501 |
| 报告人简介： |
|
| |
Dr. Ingo Barth obtained his Ph.D. degree from the University of Freie Universität Berlin, Physical and Theoretical Chemistry in 2009. He has been a leader of the Max Planck Research Group (MPRG) “Current-Carrying Quantum Dynamics” (CCQD) in the Theory Department of the Max Planck Institute of Microstructure Physics since 2014. The research of the CCQD group focuses on two subareas：1. Ionization dynamics in strong circularly polarized laser fields. 2. Analysis and control of electron and nuclear ring currents in molecules. He, 3rd generation deaf, also works in works in the development of the presently existing STEM (Science, Technology, Engineering and Mathematics) terms in German sign language, which makes deaf persons access inclusive, high-quality and free education with equal opportunity compared to other persons. |
| 报告摘要： |
|
| |
We investigated the influence of the initial rotation of the valence electron on the tunnel ionization dynamics in strong rotating (for example circularly or elliptically polarized) laser fields.
For circular polarization, we compared the analytical results of the ionization ratio between doubly degenerate current-carrying valence orbitals (for example atomic 𝑝_± or molecular 𝜋_± orbitals) with the corresponding numerical TDSE results. These results show that, in general, the nonadiabatic tunnel ionization of the counter-rotating orbital with respect to the sense of circular polarization of the laser field is preferred over the ionization of the co-rotating orbital.
Considering the spin-orbital entanglement, we also showed that highly spin-polarized photoelectrons can be produced from not only noble-gas atoms or pre-aligned but also randomly aligned nitric oxide (NO). In addition, we calculated 3D photoelectron momentum distributions (PMD) for photoelectrons emitted from pre-aligned valence 𝜋_± orbitals in the electronic ground state |Π_(1/2)>┤ of NO. We analyzed these PMDs and showed that very highly spin-polarized photoelectrons are achieved not only for slow photoelectrons but also for photoelectrons emitted at certain angles.
Furthermore, the first numerical results of 2D PMD for photoelectrons emitted from current-carrying orbitals of noble-gas atoms by strong elliptically polarized laser fields have been obtained. These results show that the angular shifts for photoelectrons released from counter- and co-rotating orbitals depend strongly on the ellipticity of the strong laser field. In particular, with decreasing ellipticity, the angular shift for the counter-rotating orbital has the opposite tendency to that for co-rotating orbital. This effect could be then used for the easier experimental separation of spin-up and spin-down photoelectrons. |
