Observation of Aharonov-Bohm interference in graphene Fabry-Pérot quantum Hall interferometers

The fractional quantum Hall effect has become the quintessential platform for investigating the properties of emergent anyons – quasiparticles which are neither fermions nor bosons. Signatures of the exchange statistics of these quasiparticles are beginning to be accessible in quantum Hall interferometers based on GaAs heterojunctions. However, the Fabry-Pérot interferometer, which is typically employed, suffers from competing charging effects that obscure the Aharonov-Bohm effect interference and signatures of anyons. Here, we use hBN-encapsulated monolayer graphene with top and bottom graphite gates to electrostatically define tunable Fabry-Pérot interferometers. Screening in the van der Waals heterostructure suppresses charging effects, yielding highly visible Aharonov-Bohm interference of integer quantum Hall edges. From this interference, we extract characteristic coherence lengths and edge mode velocities of various edges, which further demonstrate the advantages that graphene offers, and we compare gate-defined and etch-defined edge mode coherence. We will discuss progress towards interference of fractional quantum Hall modes in this system.