College of Engineering Seminars & Speakers

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Daniel Bulmash, University of Maryland, College Park

Condensed Matter Seminar - "Anomalies in (2+1)D symmetry-enriched topological phases"

Event Type
Seminar/Symposium
Sponsor
Physics - Condensed Matter
Location
ESB 190
Date
Feb 3, 2023   1:00 pm  
Speaker
Daniel Bulmash, University of Colorado, Boulder
Contact
Stephen Bullwinkel
E-Mail
bullwink@illinois.edu
Phone
217-333-1652
Views
178
Originating Calendar
Physics - Condensed Matter Seminar

Topological phases of matter, like fractional quantum Hall systems, can host anyon excitations with fractional electric charge. More generally, when topological phases with anyons have global symmetries, the anyons can carry fractional quantum numbers under those symmetries. Remarkably, some choices of fractional quantum numbers are anomalous, that is, they are physically allowed to exist, but only when the (2+1)D system lives on the surface of a bulk (3+1)D symmetry-protected topological phase like a topological insulator. Given abstract algebraic data specifying these quantum numbers, I will explain how to determine whether the resulting (2+1)D theory is anomalous and, if so, how to describe the required bulk theory.

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