Quantum Interference Controlled Spin-Polarized Electron Transmission in Graphene Nanoribbons

In graphene-based nanojunctions, the edge-topology of graphene nanoribbons (GNRs) is crucial to modulate the spin-dependent transport through quantum interference (QI). Herein we have investigated the quantum transport properties of armchair GNRs (AGNRs) and zigzag GNRs (ZGNRs) nanoribbons employing density functional theory in combination with nonequilibrium Green’s function (NEGF-DFT) techniques. The spin-polarized transmission spectra, with spin-filtering efficiency up to 50%, are observed for the ZGNRs in the low-lying ferromagnetic state. Such spin-response in the transmission spectra remains silent for the nonmagnetic AGNR and antiferromagnetic ZGNR in their respective ground states. Furthermore, upon reducing the width of ZGNR, we observed that the evolved spin-dependent QI features lead to high spin-filtering efficiency.