Transport through a network of topological states in twisted bilayer graphene

Understand

We explore a network of electronic quantum valley Hall (QVH) states in the moir\'e crystal of minimally twisted bilayer graphene.

• In our transport measurements we observe Fabry-P\'erot and Aharanov-Bohm oscillations which are robust in magnetic fields ranging from 0 to 8T, in strong contrast to more conventional 2D systems where trajectories in the bulk are bent by the Lorentz force.
• This persistence in magnetic field and the linear spacing in density indicate that charge carriers in the bulk flow in topologically protected, one dimensional channels.
• With this work we demonstrate coherent electronic transport in a lattice of topologically protected states.