Aharonov-Bohm oscillations in bilayer graphene edge state Fabry-P\'erot interferometers

TL;DR

This paper reports the design and experimental observation of Aharonov-Bohm oscillations in a bilayer graphene Fabry-Pérot interferometer, advancing the study of quantum Hall edge states and potential non-Abelian anyons.

Contribution

It introduces a novel split-gated bilayer graphene interferometer and demonstrates quantum interference at multiple integer quantum Hall states.

Findings

Observation of Aharonov-Bohm oscillations in bilayer graphene

Ability to study edge state velocities and dephasing mechanisms

Potential platform for exploring non-Abelian anyons

Abstract

The charge and exchange statistics of an elementary excitation manifest in quantum coherent oscillations that can be explored in interferometry measurements. Quantum Hall interferometers are primary tools to uncover unconventional quantum statistics associated with fractional and non-Abelian anyons of a two-dimensional system, the latter being the foundation of topological quantum computing. Graphene interferometers offer new avenues to explore the physics of exotic excitations due to their relatively small charging energies and sharp confinement potentials. Bilayer graphene possesses a true band gap to facilitate the formation of quantum confinement and exhibits the most robust even-denominator fractional quantum Hall states that may host non-Abelian anyons. Here we present the design and fabrication of a split-gated bilayer graphene Fabry-P\'erot interferometer and experimental evidence of Aharonov-Bohm interference at multiple integer quantum Hall states. The versatility of the device allows us to study a wide range of scenarios, determine the velocities of edge states, and assess dephasing mechanisms of the interferometer. These results pave the way to the quest of non-Abelian statistics in this promising device platform.