Edge state regulation and interfacial design on spin transport properties of VC2-based nanoscale devices

Edge state and interfacial design are efficient strategies to regulate the spin-transport properties of nanoscale devices. Spin-polarized transport properties of VC 2 nanoribbon device and poly-(terphenylene-butadiynylene) PTB molecular junctions are studied by using density functional theory (DFT) and non-equilibrium Green function. Results show good self-selected filtering properties for spin-up current are highly suppressed, where there is only spin-down current that can propagate through the scattering region of such a nanoribbon device. What needs to be pointed out is that spin-down current exhibits an obvious negative differential resistance effect. Current and transmission spectrum peaks are significantly weakened, and the negative differential resistance effect disappears after a PTB molecule is embedded between two semi-infinite VC 2 nanoribbon electrodes. This work provides a basis for improving the design and method of spintronic devices.