2023-07-27 |
14:50-15:35 |
2023-07-27,14:50-15:35 | LR4 (A3-2 1F) |
07-27 Afternoon Physics Lecture Room 4 (A3-2 1F)
|
Speaker |
The rise of intrinsic magnetic topological insulators In this talk, I will tell the story of the discovery of the intrinsic magnetic topological insulators (MTIs) of the MnBi2Te4 family attracting a great deal of attention nowadays. To describe the context in which the intrinsic MTIs appeared in the research arena, I will briefly discuss the magnetic doping and magnetic proximity effect approaches of introducing magnetism into TIs, whose limitations triggered the rise of materials of the MnBi2Te4 family. Then, the two types of novel topological heterostructures involving the MnBi2Te4 thin films will be discussed, which anticipated the appearance of the intrinsic MTIs. Finally, I will present our theoretical prediction and immediate experimental confirmation of the first antiferromagnetic TI, MnBi2Te4 [1]. This discovery raised a huge interest and many groups around the world instantly joined the topic that has now consolidated itself as a standalone and rapidly growing field. As a result, MnBi2Te4-based systems have been predicted or observed to show 11 different types of Hall effect. Some of them are fundamentally new, such as layer Hall effect. Besides, MnBi2Te4 is predicted to be a platform for realizing high-Chern number phases, high-order topological insulator and superconductor states, Weyl semimetal phase, axion electrodynamics, Majorana fermions, and many others. Novel device proposals specific to the MnBi2Te4 family have already been put forward, such as transistors, rectifiers, spin filters,to name a few. Quantum computing and sensing applications have also been envisioned recently. [1] M.M. Otrokov, I.I. Klimovskikh, H. Bentmann, et al. Prediction and observation of an antiferromagnetic topological insulator. Nature 576, 416 (2019).
|