Exploring Transport Properties in the 2D–3D Dirac Semimetal Heterostructures

Dirac semimetal is an emerging class of quantum matters, ranging from two-dimensional (2D) category, such as graphene and surface states of topological insulator to three-dimensional (3D) category, for instance, Cd₃As₂ and Na₃Bi. Exotic surface states in 3D Dirac semimetals is attractive for the interface engineering and the research on 2D–3D Dirac van der Waals heterostructures. Here we fabricated graphene–Cd₃As₂ heterostructure through direct layer-by-layer stacking and investigated their electron transport properties. The electronic coupling results in a notable interlayer charge transfer, which modulates the Fermi level of graphene through Cd₃As₂. This heterostructure enable us to naturally fabricate graphene p–n–p junctions, showing the quantized conductance plateaus. Moreover, the nonlocal transport studies show large nonlocal signals near Dirac point in graphene–Cd₃As₂ device, due to the charge transfer from the spin-polarized surface states in Cd₃As₂. Our results enrich the family of van der Waals heterostructures and can inspire more studies on the application of Dirac/Weyl semimetals in spintronics.