To the recorded seminar

Chiral, one-dimensional (1D) edge channels in the quantum Hall (QH) effect guide electrons dissipationless. Using quantum point contacts (QPCs) as beamsplitters, these 1D channels can be split and recombined, enabling interference of propagating electron wave functions. Such QH interferometers have been adopted to investigate quantum statistics of exotic anyon quasiparticles in the fractional QH regime. In the finite size QH interferometer, separating the magnetic field induced Aharanov-Bohm (AB) effect from Coulomb charging effects has been a technical challenge for interfering of anyons. Here, we report the graphene-based, gate-defined Fabry-Pérot (FP) QH interferometer. Widely-tunable carriers and large Landau level (LL) gaps in graphene allow engineering of QH edge channels by gate-defined electrostatics. Using QH insulating LL gaps, we fabricate tunable QPCs for integer and fractional QH edge channels. Cascading two QPCs in series, we construct FP interferometers and measure AB interference of integer QH edges. We demonstrate that edge modes are guided at large propagation velocities and long phase coherence lengths, leading to highly visible interference. The versatile and robust QH interferometer realized in our graphene heterostructure enables new routes to construct topologically protected qubits.