报告题目:Visualizing Interference Structure with Generalized Quantum Trajectory Monte Carlo Method (GQTMC)(用普适的量子轨迹蒙特卡洛方法观测干涉结构)
报告人:杨玮枫教授 (汕头大学物理系)
主持人:邓文基教授
报告时间:2017年7月11日10:30
报告地点:物理与光电学院18号楼213学术报告厅
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物理与光电学院
2017年7月7日
报告人简介: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,2007年应邀赴英国University College London做访问学者;2008年于中国科学院上海光学精密机械研究所破格评聘为副研究员;2010-2011年赴德国慕尼黑大学博士后研究员。2012年起,作为学术带头人(特聘教授)引进至汕头大学。在重要国际学术刊物Physical Review Letters, Physical Review A, Optics Express, 和Scientific Reports等上发表30余篇较高质量学术论文; 单篇SCI刊源引用超过70次。多次应邀在国内外重要学术会议作特邀报告。部分研究成果得到国际著名同行科学家的高度评价与引用。2009年获全国优秀博士学位论文奖。2008年入选上海市科技启明星计划(A类),2012年入选广东省“千百十工程”省级培养对象。2013年入选广东省“扬帆计划”引进紧缺拔尖人才。国家自然科学基金通讯评审专家,教育部学科评估专家,国家973计划学术骨干,SCI刊物Opt. Express, J. Phys. B, Applied Optics, Phys. Lett. A,Physica E, Superlattices and Microstructures, Materials Chemistry and Physics等的审稿人。
内容摘要: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,
(i). 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.
(ii). 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.
(iii). The effect of Coulomb potential and the nonadiabatic subcycle ionization on the photoelectron hologram was investigated.