EQuAL Seminar: Noah Samuelson

"Fabry-Pérot Edge State Interference as a Probe of Anyon Statistics in Graphene"

For decades, quasiparticles in the fractional quantum Hall state have been theoretically understood to obey anyonic exchange statistics, a generalization of the Fermi-Dirac or Bose-Einstein statistics of ordinary particles in three dimensions. Quantum Hall edge state Fabry-Pérot interferometers provide a means in which to study phase-coherent transport that is directly sensitive to the statistical phase of the involved quasiparticles. In recent years, this type of device was used to observe the effect of the anyonic exchange statistics of quasiparticles in a GaAs/AlGaAs quantum well [Nakamura et. al. Nature Physics 16, 931–936 (2020)]. Since then, however, the observations have not been replicated in any other material platform. Recently, we have achieved the observation of high-visibility Fabry-Pérot interference in the FQH regime in small-area (less than 1 µm2) monolayer graphene all-van der Waals gate-defined Fabry-Pérot interferometers. I will present our findings on the interference phase in the ν = 1/3 state and discuss the interpretation of the complicated interference patterns that result from the interplay between the Aharonov-Bohm effect, the anyon exchange phase, Coulomb interactions between quasiparticles, and non-equilibrium charging effects.