Ultrashort light pulses can selectively excite charges, spins and phonons in materials, providing a powerful approach for manipulating their properties. As a rapidly developing ultrafast technique, time- and angle-resolved photoemission spectroscopy (trARPES) provides important yet thermally inaccessible information for understanding the complex materials. In this talk, I will describe the high harmonic generation based trARPES and an 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 the charge density wave material 1T-TaSe2, such as the coherent electron-lattice modulation, exotic interatomic potential, mode-selective electron-phonon coupling and the resulting hidden phases.

报告人简介：Ph.D. in Physics, Institute of Physics, Chinese Academy of Sciences, China 2017.01 Advisor: Prof. Hong Ding (丁洪 研究员) Thesis: “Angle Resolved Photoemission Spectroscopy Studies of FeSe Superconducting Films and Hole-doped FeAs Superconductors” Beijing Outstanding Graduate; CAS Outstanding Graduate • B.S. in Physics, Wuhan University, China 2010.06 National Scholarship (2009); Outstanding Graduate EXPERIENCE • Postdoctoral Research Associate, JILA, University of Colorado Boulder 2017.02 – Advisors: Prof. Margaret Murnane, Prof. Henry Kapteyn Research Area: Ultrafast Science • Exchange PhD Student, Paul Scherrer Institute, Switzerland 2012.09 – 2013.11