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How to design topological superconductors from ab initio calculations

Date: 2023-03-31
Time: 10:00
Venue: EA515
Speaker: 徐刚

华中科技大学 教授

腾讯会议:247-779-712

会议密码:0331             

会议链接:https://meeting.tencent.com/dm/J2AodLMq6QVB

报告摘要

Topological superconductor (TSC) design and modulation is one of the most important but challenging task for its great potential in the topological quantum computations. In this talk, taking FeSe0.5Te0.5 and PdBi2Te4 as example, I will introduce a new paradigm to design TSC in the ideal superconducting topological metal (SCTM). 1. 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 Majorana zero modes (MZMs) at its end of vortex line, are calculated for the first time, which are confirmed by experimental observations in 2018. 2. Recently, we propose a new strategy to design the ideal SCTMs by intercalating superconducting units PdTe (or PdTe2) into topological insulator Bi2Te3, and develop a general program to calculate the TSC spectrum and its topological invariant from ab initio calculations. Our results predicts that PdBi2Te4 and PdBi2Te5 are experimentally synthesizable and ideal SCTMs, which host both the topological surface states at the Fermi level and superconductivity at 3.11 K and 0.57 K respectively. Then the chiral TSC phases are confirmed under our program for the slab calculations by incorporating topological surface states with Zeeman effect. Our results pave a 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,教授、博士生导师,2010年获中国科学院物理研究所博士学位,2010-2012年任中科院物理所助理研究员,2012-2016在美国斯坦福大学做博士后研究,2016年10月至今在华中科技大学国家脉冲强磁场中心工作。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论文70余篇,其中Nature Material、PRL等17篇,14篇论文单篇引用超过100次,高被引论文9篇,谷歌总引用10000余次,H因子34。2018年获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。

邀 请 人:沈 洁 特聘研究员

联 系 人:王慧颖 why@iphy.ac.cn