A tunable Fabry-Pérot quantum Hall interferometer in graphene
Résumé
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-Pérot 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 more than 20 µm allows us to further achieve coherently-coupled double Fabry-Pérot interferometry, as envisioned in braiding schemes of non-Abelian anyons. Our results open a new avenue for quantum Hall interferometry and the exploitation of topological excitations for quantum computation.
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