  Aharonov-Bohm (AB) interferences in the quantum Hall regime can be achieved,
provided that electrons are able to transmit between two edge channels in
nanostructures. Pioneering approaches include quantum point contacts in 2DEG
systems, bipolar graphene p-n junctions, and magnetic field heterostructures.
In this work, defect scattering is proposed as an alternative mechanism to
achieve AB interferences in polycrystalline graphene. Indeed, due to such
scattering, the extended defects across the sample can act as tunneling paths
connecting quantum Hall edge channels. Consequently, strong AB oscillations in
the conductance are predicted in polycrystalline graphene systems with two
parallel grain boundaries. In addition, this general approach is demonstrated
to be applicable to nano-systems containing two graphene barriers with
functional impurities and perspectively, can also be extended to similar
systems of 2D materials beyond graphene.
