A tunable Fabry-P\'erot quantum Hall interferometer in graphene
Abstract
Electron interferometry with quantum Hall edge channels holds promise for probing and harnessing exotic exchange statistics of non-Abelian anyons. In semiconductor heterostructures, however, quantum Hall interferometry has proven challenging and often obscured by charging effects. Here we show that high-mobility monolayer graphene equipped with a series of gate-tunable quantum point contacts that act as electron beam-splitters provides a model system to perform Fabry-P\'erot quantum Hall interferometry. We observe high-visibility Aharonov-Bohm interference free of charging effects and widely tunable through electrostatic gating or magnetic field, in remarkable agreement with theory. A coherence length of 10 \,μ m at a temperature of 0.02 K allows us to further achieve coherently-coupled double Fabry-P\'erot interferometry. Our results open a new avenue for quantum Hall interferometry and the exploitation of topological excitations for quantum computation.