Yuki Watanabe, a lecturer at the Department of Physical Engineering, Graduate School of Engineering, the University of Tokyo, has been attracting attention in recent years for international joint research with Professor Vishwanath of Harvard University, Po researcher at Massachusetts Institute of Technology, and Khalaf researcher at Maxplank Institute in Germany. We proposed a new theory that can comprehensively handle a series of substances called "topological crystal insulators" and "higher-order topological insulators".
Conventionally, substances around us have been classified by focusing on properties such as conductivity and magnetism.However, in this century, it became clear that the properties of matter change greatly due to the difference in "topology" (property that is kept unchanged against smooth deformation) that has been overlooked so far, and the topological properties of matter have become. It is being actively researched all over the world.
In recent years, this research group has been energetically studying the relationship between the topology of matter and the symmetry of crystal structure.This research further develops this and examines the relationship between the topology of new types of substances such as "topological crystal insulators" and "higher-order topological insulators" discovered by the latest research and the symmetry of the crystal structure. A detailed investigation of the structure of the metallic state of the surface.As a result of topology classification and surface state analysis based on all 230 types of symmetry of crystals, we are the first in the world to develop a comprehensive new theory for a series of topological insulators including new classes. I arrived.
This result will be a guiding principle in the search for new substances showing topological physical properties in the future, and is expected to be useful for the development of new devices, spintronics, and quantum computers that apply this principle.
Paper information:[Physical Review X] Symmetry indicators and anomalous surface states of topological crystalline insulators
