THEORETICAL PREDICTION AND CLASSIFICATION OF TOPOLOGICAL METALS: WEYL SEMIMETALS AND BEYOND

Abstract

Discovering new phases of matter and finding new materials are everlasting tasks in material science. Nowadays, the discovery of topological materials may open a new era of condensed matter physics. In the last decades, topological insulators have caught intense interest. However, research on topological metals is still sparse. One typical topological metal is the Weyl semimetal state. A Weyl semimetal is a new state of matter that hosts Weyl fermions, elementary massless chiral particles in quantum field theory, as emergent quasiparticles and admits a topological classification that protects Fermi arcs surface states on the boundary of a sample. In this thesis, I show our predictions of several Weyl semimetals, such as the first Weyl semimetal TaAs. I have also extended my work to other topological metals beyond the Standard Model. The works in this thesis provide important and timely theoretical predictions.