时　间：2019年12月31日上午10:00

地　点：高等研究院530会议室

报告人：施训

报告人简介：施训，现为美国科罗拉多大学博尔德分校博士后研究员。本科毕业于武汉大学，博士毕业于中国科学院物理研究所。主要研究方向为利用常规和超快角分辨光电子能谱(ARPES)研究超导等强关联材料。其主要工作发表在Science Advances, Nature Communications, Physical Review Letters等国际期刊。

报告题目：New insights on quantum materials from ultrafast photoemission spectroscopy

报告简介：

Time- and angle-resolved photoemission spectroscopy (trARPES) is a rapidly developing technique that combines ultrafast pump-probe scheme and powerful ARPES. It provides important yet thermally inaccessible information for understanding the complex materials, as well as holds great potential for controlling the material properties. In this talk, I will describe the high harmonic generation based trARPES and a new ultrafast electron calorimetry method that can sensitively capture the changes in the state and microscopic interactions. I will then present how we have used this technique to uncover new phenomena in magnetic and charge density wave (CDW) materials, such as the critical behavior within 20 fs that governs the ultrafast magnetic transition in Ni, the coherent electron-lattice modulation, exotic interatomic potential, mode-selective electron-phonon coupling and the resulting hidden phases in 1T-TaSe2.