DCMPMS Seminars

Exotica of Topological Materials : From Insulators to Semimetals and Superconductors

by Dr. Bahadur Singh (Department of Physics, Northeastern University, Boston, USA, "&", SZU-NUS Program, College of Optoelectronic & Physics Engineering, Shenzhen University, China)

Wednesday, August 7, 2019 from to (Asia/Kolkata)
at AG80
Description
An entirely new paradigm for classifying materials based on their band topologies has led to the exciting discovery of topological states of quantum matter. These exotic states are characterized by nonzero topological invariants and support protected boundary as well as bulk states and exhibit unique responses to electric and magnetic fields. The combination of crystalline symmetries (symmorphic as well as nonsymmorphic) with time-reversal and particle-hole symmetries, has yielded many theoretical proposals for a variety of topological states with their own unique properties, and a number of these proposals have been realized experimentally. I will discuss how topology enters the realm of materials physics at a fundamental level through the properties of electronic wavefunctions in crystalline solids. I will give an overview of our extensive theoretical effort aimed at the prediction of materials platforms which can support not only Weyl, Dirac, and Majorana fermions that are familiar from high-energy physics but also other more exotic fermions that have no high-energy counterparts. Our studies combine the latest developments in first-principles, parameter-free approaches within the emerging field of topological band theory. I will highlight some of our recent breakthroughs toward modelling correlated topological Kondo insulators, magnetic topological materials, topological superconductors as well as quantum spin-Hall insulators with large band gaps capable of surviving room temperature thermal excitations with exciting potential for spintronics, energy and information sciences applications.