Fig. 5: Ferroelectric switching of topological valley current.
From: Giant ferroelectric polarization in a bilayer graphene heterostructure

a The internal electrical polarization P3D (State 2) keeps almost the same below 100 K, but gradually decays at higher temperature. b, c Local b and nonlocal c signals are compared at 50 K. Only at CNP the nonlocal resistance could be observed. Inset: Measurement schemes. d The scaling of RNL~RL3 is consistent with the topological valley transport.