Resonant tunneling in monolayer WSe₂/graphene/h-BN/graphene junctions

When graphene is placed on a monolayer transition metal dichalcogenide (TMD), spin splitting in the graphene band greatly enhances due to the proximity effect of spin-orbit interaction from the TMD layer. Here, we report the resonant tunneling in monolayer WSe₂/graphene/thin h-BN/graphene junctions, where one of the graphene layers is placed on monolayer WSe₂ with a twist angle of ~15° and the twist angle between the two graphene layers is controlled around 0.5° through the thin h-BN barrier. In low temperature tunneling transport measurements (T ~ 1.5 K), we observed energy and momentum conserved coherent resonant tunneling between the bands of two graphene layers due to the small twist angle. The differential conductance shows splitted peak structures likely due to the spin splitted band of the graphene on WSe₂. Comparing the experimental results with theoretical calculation, we estimated the magnitude of spin splitting in the graphene/WSe₂ is about ~20 meV which is consistent with previous experimental researches. Our results indicate coherent resonant tunneling can be a good way to study the proximity effect in graphene on various materials including TMDs.