报告人：Prof. Sven Ahrens，Shanghai Normal University (上海师范大学)
报告时间：2019年10月25号下午14:00
报告地点：理科楼LE201
报告摘要：The superposition of two counter-propagating laser beams is forming a standing wave of light, which can act as optical grating for traversing particles. This effect has already been discussed in 1933 by Kapitza and Dirac [1] and was demonstrated experimentally by Freimund, Aflatooni and Batelaan [2]. Nowadays, one of the main applications of the Kapitza-Dirac effect is the usage of diffraction for the study of macroscopic quantum objects in interference experiments [3]. Also electron spin effects are considered to be possible in the Kapitza-Dirac effect [4,5], though only for very specific parameters. In my talk, I will present a momentum space description for solving the relativistic quantum dynamics (Dirac equation) of the electron wave packet in a standing light wave. Based on this method I will discuss the possibility of spin effects and also spin-dependent diffraction from numeric and analytic solutions of the theoretical quantum description. At the end I will further discuss considerations about the experimental feasibility of spin-dependent electron diffraction.
[1] Kapitza and Dirac, Math. Proc. Cambridge Philos. Soc. 29, 297 (1933).
[2] Freimund, Aflatooni and Batelaan, Nature 413, 142 (2001).
[3] Arndt, Nairz, Vos-Andreae, Keller, van der Zouw and Zeilinger, Nature 401, 680 (1999).
[4] Ahrens, Bauke, Keitel and Müller, Phys. Rev. Lett. 109, 043601 (2012).
[5] Dellweg and Müller, Phys. Rev. Lett. 118, 070403 (2017).
报告人介绍：Prof. Sven Ahrens carried out his PhD about relativistic quantum dynamics at the Max-Planck-Institute for Nuclear Physics in Heidelberg in 2012. After a short time at the Intense Laser Theory group at the Illinois State University in Illinois, USA, he went to the Beijing Computational Science Research Center (北京计算科学研究中心), where he studied the emulation of relativistic quantum dynamics in metamaterials and intrinsic angular momentum transfer in intense laser fields. Currently, Prof. Ahrens is affiliated at the Shanghai Normal University (上海师范大学), where he is continuing feasibility studies on spin-dependent electron dynamics in x-ray laser fields.
欢迎各位老师和同学参加！
