报告题目：Ultrafast Microscopy of Structured Light-Matter Wave - a Gateway to Axion Physics
报告人：Prof. Hrvoje Petek (美国匹兹堡大学)
报告时间：2023年11月21日（周二）上午 10:00-11:00
报告地点：物理学院新楼五楼多功能厅
Abstract:
Light travels at 300 nanometers per femtosecond, and nothing is faster than that. Then how can we take movies of light with resolution below its space/time period of oscillation as it propagates at a metal-vacuum interface as a light-matter charge density surface wave? We accomplish this by photoemission electron microscopy where we image its path by recording the spatial distributions of electrons that have absorbed two photons. Scanning the pulse delay with 0.05 fs precision records images of plasmon fields as they evolve by 15 nm in every frame. We apply this methodology to image structured light in form of plasmonic vortices where optical fields are made to circulate in space as water going down a drain1. In vortices, the normally transverse electric and magnetic fields in vacuum, become parallel. Such fields can drive coherent magnetoelectric phenomena, driving electron charge and spin responses, potentially interacting with the putative axion quasiparticles in condensed matter. We perform ultrafast microscopy of light towards Poincaré engineering2 of high energy physics phenomena at a laboratory scale. (在我们世界，没有比光传播更快的东西。那么，有没有办法追踪光的足迹，为光的传播 “拍摄电影”?在本次报告中，Hrvoje Petek教授将为大家介绍如何在实验室通过超快激光与物质相互的作用来“追”光。)
1. Y. Dai, at al., Nature 588, 616 (2020)
2. Y. Dai, et al., Nature Reviews Physics 4, 562 (2022)
Biography:
Hrvoje Petek教授1980年和1985年分别在麻省理工学院与加州大学伯克利分校获得学士与博士学位，之后在日本分子科学研究所(1985-1993)和日立高等研究中心(1993-2000)工作，2000年加入匹兹堡大学物理与天文学系，并挺任R. K. Mellon 讲席教授至今。他的研究兴趣涉及固体表面的超快光谱学、显微镜和飞秒化学。他开创了飞秒时间和纳米空间相干电子动力学的超快多光子光电发射谱研究。他获得的荣誉包括Alexander von Humboldt Research Award (2000), Morino Award (2014), Ahmed Zewail Award in Ultrafast Science and Technology (2019)等, 并入选美国物理学学与艺术学会(AAAS)会士。
邀请人：丰敏 教授
