报告题目：Attosecond Time Delay of Retrapped Resonant Ionization

报告人：杨玮枫  教授

工作单位：汕头大学

时间：2019年9月17日16：00-17：30

地点：浮山校区博逸楼401

内容简介：

A recent ultrafast pump-probe technique has allowed measurement of time delays during photoemission in a variety of systems ranging from atoms and molecules to solids with unprecedented temporal resolution. However, identifying the underlying physics is still a challenge especially in complicated multichannel above-threshold ionization (ATI) experiments. Here we demonstrate that the time delays of different ionization pathways in ATI can be clearly resolved and extracted with a semiclassical statistical method. The remarkable phase shift of near threshold photoelectrons can be attributed to a temporary retrapping of a photoelectron by the atomic potential in quasibound states after emerging in the continuum state. This continuum-bound-continuum scattering manifests as a new resonant effect in strong-field photoemission. Our results unify the seemingly opposing quantum Eisenbud-Wigner-Smith time delay and classical Coulomb-induced time delay by highlighting the same physical picture, which holds promise for an intuitive interpretation of time-resolved fundamental electronic processes in strong-field experiments and epistemological reexamination of the quantum-classical correspondence.

个人简介：杨玮枫，汕头大学卓越计划拔尖层次特聘教授、博士生导师，广东省物理学会理事会理事，广东省“先进光学与光电子学”创新团队负责人。从事激光光电子学研究。以第一作者/通讯作者在重要国际SCI学术刊物发表高质量学术论文三十余篇，（其中包括物理学顶级学术期刊Physical Review Letters 3篇); H因子为14，单篇SCI刊源引用超过80次。多次应邀在国内外重要学术会议作特邀报告。2008年入选上海市科技启明星计划， 2009年获全国优秀博士学位论文奖， 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。

先后主持和承担包括三项国家自然科学基金、广东省创新团队（自然科学）项目和广东省自然科学基金重点项目在内的科研项目十余项，现研究组在研项目经费500余万。国家自然科学基金通讯评审专家，教育部长江学者通讯评审专家，国际著名SCI刊物ACS Photonics, Opt. Lett., Opt. Express, New J. Phys.等的特邀审稿专家