报告题目：How to design topological superconductors from ab initio calculations

报告人：徐刚教授 华中科技大学

邀请人：王健教授

时 间：9月20日（周五）下午14：30至16：00,

地 点：腾讯会议，会议号：813 798 881，会议链接: https://work.weixin.qq.com/webapp/tm/AEQSWzZZak9auWqqCjkVAc

Abstract:

Topological superconductor (TSC) design and Majorana zero mode (MZM) modulation are the most important but challenging task for their great potential in the topological quantum computations. In this talk, I will introduce two new paradigms to realize TSC and MZM. One is the TSC and MZM in the vortex of superconducting topological metal (SCTM). The other is the Chiral TSC in the OAI-SC heterostructure. In 2016, we innovatively propose a new scheme to realize TSC in ideal SCTM, which host the inverted band structures and superconductivity simultaneously. The TSC properties of FeSe0.5Te0.5, as well as MZMs at its end of vortex line, are calculated for the first time, which are confirmed by experimental observations in 2018. In 2023, we predict that PdBi2Te4 and PdBi2Te5 are experimentally synthesizable and ideal SCTMs, and develop a general program to calculate 2D TSC spectrum and its topological invariant from ab initio calculations. Recently, based on the obstructed surface states of the obstructed atomic insulator (OAI), we propose a new strategy to realize the 2D chiral TSC in NbSe2-Nb3Br8- CrI3 heterostructure, which could avoid the subband problem effectively. These works pave new way to realize TSC and MZMs in a large class of materials and provide a general tool to design and modulate the TSC system from ab initio calculations.

报告人简介:

徐刚，知名学者特聘教授，海外高层次青年人才，华中科技大学教授、博士生导师；长期致力于发展和应用第一性原理计算方法从原子层面设计新型量子功能材料，探索新量子物态。已取得的重要成果包括：1. 拓展了拓扑半金属的概念和范围，预言了HgCr2Se4、EuCd2As2、FeSe等优质磁性拓扑材料并被实验证实。2.发现了KV3Sb5等笼目化合物的拓扑物性、CDW和手性电荷并被实验观测，引发了大量关注和跟进研究。3.提出了拓扑超导设计新范式，预言了Fe(Se,Te)中的拓扑超导态被实验实现。4.开发了多极矩序参量高效计算方法，发现了RuI3中的纯八极矩基态。发表SCI/EI论文80余篇，其中Nature Material、PRL等27篇，19篇论文单篇引用超过100次，高被引论文9篇，总引用13000多次， H因子41。获2018年中国科学院杰出科技成就奖集体，主持国家重点研发计划1项、基金委面上项目2项。