Michael Manfra: Fractionalization of Charge and Statistics: Anyons in Condensed Matter Systems

Michael Manfra

Purdue University Bill & Dee O’Brien Distinguished Professor of Physics & Astronomy Professor of Electrical and Computer Engineering Professor of Materials Engineering

"Fractionalization of Charge and Statistics: Anyons in Condensed Matter Systems"

Abstract: A basic tenet of quantum theory is that all elementary particles are either bosons or fermions. Ensembles of bosons or fermions behave differently due to differences in their underlying quantum statistics. Starting in the late 1970’s it was theoretically conjectured that excitations that are neither bosons nor fermions may exist under special conditions in two-dimensional interacting electron systems. These unusual excitations were dubbed “anyons.” Anyons possess fractional charge and fractional statistics and are expected to reside in a variety of topological phases of matter, however directly probing these properties presents experimental challenges. This seminar will focus on the development of electronic Fabry-Pérot interferometers that resulted in the direct observation of anyonic braiding in the fractional quantum Hall state at ν=1/3. These techniques have now been extended to the more fragile multi-edge-mode hierarchy state at ν=2/5 and the technique may provide utility for a variety of condensed matter systems in which anyons are believed to exist.