Description:

Title: New topological phases and effects in solids

Speaker: Joel Moore, UC Berkeley and Lawrence Berkeley National Laboratory

Abstract: 

Much of condensed matter physics is concerned with understanding how different kinds of order emerge from interactions between a large number of simple constituents. In ordered phases such as crystals, magnets, and superfluids, the order is understood through "symmetry breaking": in a crystal, for example, the continuous symmetries of space under rotations and translations are not reflected in the ground state. A major discovery of the 1980s was that electrons confined to two dimensions and in a strong magnetic field exhibit a completely different, topological type of order that underlies the quantum Hall effect.

Topological order also occurs in some materials, dubbed "topological insulators”, in zero magnetic field. Spin-orbit coupling, an intrinsic property of all solids, drives the formation of the topological state. There are also topological Dirac and Weyl semimetals that generalize the massless electronic structure of graphene to 3D.

This talk will explain what topological order means, then give an overview of
the new topological phases and the unusual transport and optical responses they
enable.

Host: Goswami

Speaker Schedule

Keywords: Physics, Astronomy, colloquium