2D spin transport through graphene-MnBi₂Te₄heterojunction

The development of two-dimensional (2D) magnetic semiconductors promotes the study of nonvolatile control of magnetoelectric nanodevices. MnBi₂Te₄is the first realization of antiferromagnetic topological insulator. In semiconductor circuits, metal-semiconductor contacts are usually essential. In future all-carbon circuits, graphene is a promising material for 2D conductive connections. This work studies electronic transport through graphene-MnBi₂Te₄-graphene junctions. We find that graphene-MnBi₂Te₄interfaces are perfect Ohmic contacts, which benefits the use of MnBi₂Te₄in carbon circuits. The currents through MnBi₂Te₄junctions possess high spin polarization. Compared with usual van der Waals junctions, lateral graphene-MnBi₂Te₄-graphene junctions present a lower barrier and much higher conductance to electrons. These findings may provide guidance for further study of 2D spin filtering.