Nonlocal conductance control of a zigzag F/S/F graphene nanoribbon junction

Abstract

We report a theoretical study of nonlocal charge and spin conductances in a zigzag-graphene-nanoribbon-(ZR)–based ferromagnet/superconductor/ferromagnet (F/S/F) junction. When the zigzag-chain number of the ribbon is even and only the edge states are involved in transport, the ferromagnetic ZR (FZR) resembles a half-metal and the crossed Andreev reflection dominates over the elastic cotunneling of the electron in the antiparallel magnetic configuration of the junction. It is demonstrated that both the nonlocal charge and spin conductances in the F/S/F ZR junction can be modulated arbitrarily by variation of the cross angle of the two magnetic moments in each FZR, the S layer length, and the gate voltage applied on the S region. Our findings may shed light on devising spin devices based on magnetized graphene nanoribbons.