报告题目：Intrinsic chiral topological superconductor and its universal topological quantum computation

报告时间：2022年11月9日 16:00

报告地点：腾讯会议（会议号：643 472 311）

报告摘要：

   Superconductors (SCs) with nontrivial topological band structures in the normal state have been discovered recently in bulk materials. When such SCs are made into thin films, quantum tunneling and Cooper pairing take place between the topological surface states (TSS) on the opposing surfaces. Here, we find that chiral topological superconductivity with spontaneous time-reversal symmetry breaking emerges on the surface of such thin film SCs. There is a mirror symmetry that protects a novel nonunitary orbital and spin triplet pairing of the TSS. A rich topological phase diagram governed by the nontrivial Z⊕Z topological invariant is obtained. We further construct a 3D lattice model with a topological band structure and SC pairings, which is motivated by Fe-based SCs such as Fe(Te,Se). We demonstrate the realization of the proposed intrinsic chiral topological superconductor in the quasi-two-dimensional thin film limit. Our findings enable thin film SCs with nontrivial Z2 band structures as a new single-material platform for intrinsic chiral topological superconductivity. Furthermore, non-abelian braiding operations can be achieved by using two pairs of chiral Majorana edge modes, and with interactions, a topological CNOT gate can be assembled, which paves a new way for fault-tolerant universal topological quantum computing.

报告人简介：

   罗熙，上海理工大学副教授，硕士生导师，2005年至2015年在复旦大学学习，获得学士、博士学位，期间曾在University of Utah作访问学者。2015年09月至2017年11月于中国科欧冠赛事下注平台理论物理研究所进行博士后研究。研究兴趣集中于拓扑物态，拓扑量子计算和量子场论，于Physics. Rev. B，Physics. Rev. D等期刊发表文章多篇。