Room-temperature spin-lifetime anisotropy exceeding 60 in bilayer graphene spin valves proximity coupled to WSe ₂

Abstract A spin lifetime anisotropy between in-plane and out-of-plane spins in bilayer graphene (BLG) can be achieved by spin–orbit proximity coupling of graphene to transition metal dichalcogenides. This coupling reduces the in-plane spin lifetime due to proximity-induced spin scattering, while the out-of-plane spin lifetime remains largely unaffected. We show that at room temperature spin lifetime anisotropy exceeds 60 in a BLG lateral spin valve proximity coupled to WSe ₂ . The out-of-plane spin lifetime of about 250 ps closely matches that of a BLG reference region not in contact with WSe ₂ . In contrast, the estimated in-plane spin lifetime of less than 4 ps leads to a complete suppression of the in-plane spin signal measured at the ferromagnetic Co/MgO spin detector. The proximity coupling of WSe ₂ to BLG is particularly promising, as it does not compromise the charge carrier mobility within the graphene channel.