Intrinsic magnetic topological insulator MnBi2Te4
author: time:2019-09-23 clicks:
Time and place: 2019.9.23, 16:00 pm, Wuhan National High Magnetic Field Center C204
Presenter: Yong Xu
Title: Intrinsic magnetic topological insulator MnBi2Te4
Abstract:
The interplay of magnetism and topology is a key research subject in condensed matter physics and material science, which offers great opportunities to explore emerging new physics, like the quantum anomalous Hall (QAH) effect, axion electrodynamics and Majorana fermions. However, these exotic physical effects have rarely been realized in experiment, due to the lacking of suitable working materials. In this talk, we will present our recent findings of intrinsic magnetic topological insulators in van der Waals layered MnBi2Te4-family materials. The materials intrinsically show two-dimensional (2D) ferromagnetism in the single layer and three-dimensional (3D) A-type antiferromagnetism in the bulk, which could serve as a next-generation material platform for the state-of-art research. We predict extremely rich topological quantum effects with outstanding features in an experimentally available material MnBi2Te4, including a 3D antiferromagnetic topological insulator with the long-sought topological axion states, the type-II magnetic Weyl semimetal (WSM) with one pair of Weyl points, and intrinsic QAH insulators and axion insulators. Recent theoretical and experimental progresses will be introduced. As important progresses, we experimentally observed two exotic topological phases (i.e., axion insulator and Chern insulator) and quantum phase transition between them in one stoichiometric crystal MnBi2Te4 at relatively high temperature.