主讲人：唐峰，南京大学副教授
时 间：2024年7月8日 15:00
地 点：物电学院A栋112
联系人：童庆军
讲座摘要：The realization of Hopf-link structure composed of several nodal loops that are nested with one another in the Brillouin zone is rather rare hindering the comprehensive exploration and understanding of such exotic nodal loop geometry. In this talk, I will demonstrate using group theory to realize the Hopf-link: 1. We investigate Phonon Database at Kyoto University consisting of 10034 materials to search for phonon realization of the Hopf-link nodal structure by a symmetry-based algorithm. It is found that almost all the investigated materials own nodal loops while only 129 materials can host Hopf-link structure in phonon spectrum, among which 8 materials are manually selected with relatively clean Hopf-link. The visible phonon drumhead surface states corresponding to the nodal loops in the Hopf-link structure. The listed 129 crystalline materials provide a good platform for experimentalists to further explore the interesting properties related with Hopf-link structure. 2. We provide effective k∙p models around the so-called real triple points pinned at high-symmetry points in the 1651 magnetic space groups containing the combination of spatial inversion and time-reversal symmetries. We list 386 materials with at least one real triple point in the phonon spectra, which evolves into Hopf-link by symmetry-breaking gapping the triply-fold degenerate point.
主讲人简介：唐峰，2007~2019年在南京大学物理学院学习，2019年取得博士学位，2019年9月至2023年2月于南京大学做专职科研岗（特任研究员），2023年3月转为助理教授，同年，基于助理教授以前的学术成果获得了国家优秀青年，因而自动转为准聘副教授。研究兴趣主要包括：拓扑物态和拓扑材料、超越传统空间群应用新方案的发展、基于对称性物性研究和材料预测等。
