Fabry-Perot interferometer in bilayer graphene

Quantum Hall edge state interferometry has been an important tool in probing the charge and statistics of elementary excitations of the quantum Hall and fractional quantum Hall effect of a two-dimensional electron gas. Decades of effort and the recent observation of fractional statistics in screened GaAs quantum wells highlight the importance of a small Coulomb charging energy and a sharply defined edge confinement potential [1]. High-quality bilayer graphene is an appealing platform because it exhibits a plethora of odd and even-denominator fractional quantum Hall states with large energy gaps and a dual-gated graphene/BN heterostructure is conducive to the reduction of Coulomb charging energy and edge reconstruction. In this work, we report on the fabrication and measurements of interferometer devices in bilayer graphene using different designs. We determine relevant energy and length scales revealed in our measurements and discuss the progress and challenges towards detecting fractional and non-Abelian statistics in this platform.
[1] Nakamura et al., Nat. Phys. 16, 931–936(2020)