Department of Physics, Columbia University

Abstract：

As praised by P. W. Anderson, collective elementary excitations, established by the work of L. D. Landau, D. Pines, and many others, are “probably the single most fruitful theoretical concept in all of the solid-state physics.” The elementary excitations, such as plasmons, phonons, magnons, and excitons, govern the properties of quantum materials. Notably, the strong coupling of the elementary excitations and light forms light-matter hybridized states known as polaritons, which possess half-light and half-matter nature and provide an unparalleled opportunity to control, probe, and create emergent quantum states [1]. In this talk, I will first investigate the plasmon polaritons in the two-dimensional superlattices, actuated by moiré polarization, and then establish a new strategy to probe the electrical polarization [2]. In the second part, I will show the magnetic order enhanced exciton oscillator strength and demonstrate the first experimentally discovered hyperbolic exciton-polaritons in CrSBr [3].

Reference：

1.Science 354, aag1992 (2016).

2.Nat. Commun. 14, 6200 (2023).

3.Nat. Commun. 14, 8261 (2023).

Brief CV of Dr. Shuai Zhang:

Shuai Zhang is an Associate Research Scientist at Columbia University. He earned his PhD from Fudan University in 2017. Following graduation, he worked as a Xide Postdoctoral Fellow for one year before joining Columbia University. At Fudan University, he pioneered the development of the close-cycle variable temperature Scanning Tunneling Microscope (STM) and coupled the STM with light. Subsequently, at Columbia University, he developed a state-of-the-art cryogenic Scattering-type Scanning Near-field Optical Microscope (cryo-sSNOM). Leveraging these innovative and powerful techniques, he explores the elementary excitations in low-dimensional quantum systems.

报告地点：M楼253会议室

腾讯会议ID:  582-899-620

会议密码：0506

主持人：赵继民  研究员

联系人：傅琦（82649469）