Special CPM Seminar

Enhanced Bulk-Edge Coulomb Coupling in Fractional Fabry-Perot Interferometers

Bernd Rosenow

Leipzig University

When the orbital motion of quantum particles is confined to two dimensions, their quantum statistics can go beyond the plus or minus sign characterizing the spatial exchange of bosons or fermions. In the case of Abelian anyons, moving one particle around the other is described by a multiplication of the wave function with an arbitrary complex phase. In addition, the possibility of Non-Abelian anyonic statistics has been discussed, where the spatial exchange of particles leads to a transformation of the quantum state.

Motivated by recent experimental claims that the ν = 5/2 quantum Hall state exhibits non-Abelian topological order, I will reexamine the theory of Fabry-Perot interferometers. Even a moderate Coulomb coupling may strongly affect some fractional plateaus, but very weakly affect others, allowing us to model the data over a wide range of plateaus. While experiments are consistent with the ν = 5/2 state harboring Moore-Read topological order, they may have measured Coulomb effects rather than an “even-odd effect” due to non-Abelian braiding.