Disorder and topology in modern condensed matter physics


Professor Victor Gurarie, Center for the Theory of Quantum Materials and Department of Physics, University of Colorado, Boulder
Parnell (7), Rm 222, 12 pm

The study of the effects of impurities in crystals is an old subject in condensed matter physics. Usually abbreviated as the study of disorder, it led to at least one Nobel prize and countless publications over the last 60 years. The identification of states of matter whose formation is governed by topology, as opposed to symmetry, is a relatively new subject. Having its roots in the discovery of quantum Hall effect, this field took off in the last decade and became a vibrant and intellectually stimulating subject within condensed matter physics. It might not be obvious from their descriptions, but topology and disorder are inexplicably linked together. Understanding how topological states respond to the presence of impurities became an important tool for developing both subjects. It also has direct experimental implications. In this talk I will describe the relationship between topology and disorder on the examples of quantum Hall effect, topological insulators and Weyl semimetals.