Princeton University Donald R. Hamilton Colloquium Series

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 lecture will focus on the development of electronic Fabry-Pérot interferometers that resulted in the first direct observation of anyonic braiding in the fractional quantum Hall state at ν=1/3. These experiments 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.