Description:

Title: Quantum criticality and topology of massless Dirac and Weyl fermions

Speaker: Dr. Pallab Goswami, University of Maryland

Abstract: The Dirac and Weyl equations were originally introduced for describing elementary particles. Recently, these same equations are being extensively used for describing low energy fermionic excitations of many condensed matter systems. While gapped topological phases can be understood in terms of massive Dirac fermions, the massless Dirac and Weyl fermions are known to combine two seemingly disjoint notions of quantum critical bulk excitations and topology. After introducing their critical and topological properties, I will discuss some potential applications as well as the challenging aspects of their experimental detection. I will show how we can gain new insights into itinerant quantum critical phenomena and strongly coupled gapless states by studying the stability of interacting and dirty Dirac fermions. I will also outline some future directions of research on correlated materials, which can display a confluence of competing orders, topology and strongly interacting gapless phases.

Host: James Sauls

Condensed Matter, Physics, Astronomy