萨本栋讲坛之116期

题     目: Vortex states and Majorana zero modes in FeSe based high-Tc superconductors

主  讲 人:  张童 教授  （复旦大学）

时间地点： 2021年6月18日（周五）下午14：30，物理楼552  

主讲人简介：张童，2004年本科毕业于山东大学，2010年博士毕业于中科院物理所，现任复旦大学物理系教授。主要利用极低温扫描隧道显微镜、高分辨扫描隧道谱和原位薄膜生长等来研究非常规超导体和低维拓扑材料的微观电子态和机理。在Nat. Phys.，PRL，PRX，Sci. Adv.，Nat. Comm.，Nano letter 等国际期刊上发表文章48篇，它引4000余次。2015年获基金委优秀青年基金，现主持基金委重大研究计划重点项目、科技部重点研发计划（课题）等科研项目。

Abstract：As a novel quantum state, Majorana zero mode (MZM) has become a hot topic due to its applications in topological quantum computing. Theories predict that MZM can appear in the vortex core of a topological superconductor as a unique bound state. However, due to the existence of trivial low-energy vortex states or impurity states, it is usually difficult to identify MZM and study their physical properties. In this talk, I will introduce our recent high resolution STM studies on vortex state of FeSe based High-Tc superconductors. We found clear zero-energy mode which well separated from other high-level vortex state in the intercalated (Li, Fe)OHFeSe. Its non-trivial nature is supported by evidence of quantized conductance, and the distinct spatial distribution with comparing to other high-energy level states. As for single-layer FeSe/SrTiO3 film, it only displays conventional Caroli-de Gennes- Matricon (CdGM) states without zero-energy mode. These results provide critical information on the fast-developing field of topological superconductivity and MZM.