  At near-parallel orientation, twisted bilayer of transition metal
dichalcogenides exhibit inter-layer charge transfer-driven out-of-plane
ferroelectricity that may lead to unique electronic device architectures. Here
we report detailed electrical transport in a dual-gated graphene field-effect
transistor placed on 3R stacked twisted bilayer of WSe2 at a twist angle of 2.1
degree. We observe hysteretic transfer characteristics and an emergent charge
inhomogeneity with multiple local Dirac points as the electric displacement
field (D) is increased. Concomitantly, we also observe a strong non-local
voltage signal at D = 0 V/nm that decreases rapidly with increasing D. A linear
scaling of the non-local signal with longitudinal resistance suggests edge mode
transport, which we attribute to the breaking of valley symmetry of the
graphene channel due to the spatially fluctuating electric field from the moire
domains of the underlying twisted WSe2. A quantitative analysis connecting the
non-locality and channel inhomogeneity suggests emergence of finite-size
domains in the graphene channel that modulate the charge and the valley
currents simultaneously. This work underlines efficient control and impact of
interfacial ferroelectricity that can trigger a new genre of devices for
twistronic applications.
