南方科技大学

报告摘要:

Exploring the realms of physics that extend beyond thermal equilibrium has emerged as a crucial branch of condensed matter physics research. It aims to unravel the intricate processes involving the excitations, interactions, and annihilations of quasi- and many body particles, and ultimately to achieve the manipulation and engineering of exotic non equilibrium quantum phases on the ultrasmall and ultrafast spatiotemporal scales. In this talk, I will first introduce the ultrafast time-resolved photoemission electron microscopy (tr PEEM) technique as a means of studying non-equilibrium physics in condensed matter materials. Next, I will focus on the discussion of the one of the primary applications of tr PEEM, which is the imaging of surface plasmonic responses, including the coherent vectorial imaging of surface plasmon polariton fields and spin textures, spatiotemporal evolution of localized surface plasmons, as well as plasmon-induced hot electron transport in real space. Finally, I will briefly describe our effect in extending tr-PEEM as a multi dimensional probe for studying excited state physics beyond plasmonics.

Reference:

[1] Y. Dai, et.al., Ultrafast Ferroelectric Ordering on the Surface of a Topological Semimetal MoTe2. Nano Lett., 21, 9903 (2021).

[2] Y. Dai, et.al., Plasmonic Topological Quasiparticle on the Nanometre and Femtosecond Scales. Nature, 588, 616 (2020).

报告人简介:

Yanan Dai is an associate professor in the department of physics, Southern University of Science and Technology (SUSTech). He obtained his B.S. degree at Shandong University in 2013, and Ph.D degree in physics at the University of Pittsburgh in 2019. Before joining SUSTech in Aug. 2022, he worked as a postdoctoral research scientist in the department of chemistry at the Columbia University. His group at SUSTech now is developing advanced ultrafast optical and photoelectron spectroscopies and microscopies, to achieve multi dimensional detection of excited state dynamics and vectorial Floquet engineering of quantum materials on the nano-femto scales.

邀请人：杨海涛研究员（82648072）