Description:

Title: Fractionalization in quantum matter: past, present and future

Speaker: Dr. Inti A. Sodemann, Massachusetts Institute of Technology

Abstract: Up until a few decades ago we used to believe that the low energy excitations in any phase of matter could be understood either as dressed versions of the bare particles or as bosonic collective modes like sound waves. Toward the end of the 20th century a lucky combination of experimental discoveries and theoretical insights shattered this paradigm and made clear that stable excitations can exist that behave like fractions of the bare particles. In this talk, I will describe a few selected recent developments in our understanding and realization of fractionalized phases in the quantum Hall regime. In particular, I will explain how electrons in graphene exhibit a rich structure of fractionalized phases coexisting with complex symmetry breaking patterns. I will also describe our recent elucidation of a remarkable connection between two venerable exotic quantum Hall liquids: the composite fermi liquid and the Bose-Einstein condensate of excitons realized in quantum Hall bilayers. Specifically, I will show that the exciton condensate is identical to an interlayer superconductor of composite fermions. I will close with some thoughts on the future of fractionalization and on its potential realization outside the realms of large magnetic fields and frustrated magnets.

Host: James Sauls

Condensed Matter, Physics, Astronomy