学　术

　　为加强我校各学科之间的学术交流，搭建教师学术交流平台，促进教师学术水平提升和跨学科合作，教师发展中心开展跨学科学术沙龙活动。

　　本次活动教师发展中心邀请了2009百篇优博获得者、汕头大学特聘教授杨玮枫，与我校师生分享他在信息医疗领域的研究心得。具体安排如下，欢迎感兴趣的师生参加：

　　一、主　题：Visualizing Interference Structure with Generalized Quantum Trajectory Monte Carlo Method（GQTMC)

　　二、主讲人：汕头大学 杨玮枫 特聘教授（2009百篇优博获得者）

　　三、时　间：2017年6月26日（周一）15:20

　　四、地　点：沙河校区科研楼204会议室

　　五、主持人：物理电子学院 徐军 教授

　　六、内容简介：

　　Strong-field photoelectron spectroscopy encodes temporal and spatial information about both the electron and the ion dynamics. To extract this dynamical information, one needs a full understanding of the physical mechanism underlying the complicated interference structures in the photoelectron spectrum. We developed a Generalized Quantum Trajectory Monte Carlo (GQTMC) method which could apply to arbitrary values of the Keldysh parameter. Our simulations agree well with both the experimental and TDSE results. It provides an efficient way to probe the interference structures and the underlying electronic dynamics in photoelectron momentum distribution. With the GQTMC method and experimental data,

　　(1) For the first time, we observed a Freeman resonance time delay in multiphoton ionization of an atom, which is clocked to be 140 attoseconds by using a phase-controlled two-color femtosecond laser pulse.

　　(2) A new form of Coulomb-field-driven backward-scattering of photoelectrons in the direction transverse to the laser field is identified to be responsible for a novel and universal curved interference structure in the photoelectron momentum distribution, which has been confused with the holographic interference structure (reported firstly in [Science 331, 61(2011)]) within the strong field physics community for a long time.

　　(3）The effect of Coulomb potential and the nonadiabatic subcycle ionization on the photoelectron hologram was investigated.

　　(4）A profound ringlike pattern coming from the interplay between the intra- and the intercycle interferences of electron trajectories can be observed in the deep tunneling ionization regime, and an appropriate experimental condition for the observation of the photoelectron holography was provided.

　　七、主讲人简介：

　　杨玮枫，2007年毕业于中国科学院上海光学精密机械研究所获博士学位，现任汕头大学特聘教授。2009年全国百篇优博奖获得者。国家自然科学基金通讯评审专家，国家973计划学术骨干，国际SCI刊物 Opt. Lett., Opt. Express, J. Phys. B, Applied Optics, Phys. Lett. A，Physica E, Superlattices and Microstructures, Materials Chemistry and Physics，Chinese Optics Letters, 物理学报等的审稿人。

　　八、主办单位：人力资源部教师发展中心

　　　　承办单位：物理电子学院

                             人力资源部教师发展中心

                               　2017年6月23日