Spin-orbit coupling effects on electronic transport in group‑Ⅳ graphene‑like materials

A systematic theoretical study was investigated on the electronic transport characteristics in group-Ⅳ graphene-like structures using the non-equilibrium Green's function method. This article mainly analyzes the mechanism of intrinsic effective spin orbit coupling(SOC)and Rashba SOC in small-sized systems, and their effects on transport pathways, conductivity, and band characteristics. The results show that under weak intrinsic SOC, electrons tend to be transported through tunneling channels between edge states. When the intrinsic coupling strength increases, the interaction between edge states diminishes, causing more electrons to propagate along the edges. After introducing Rashba SOC, spin-flipping can occur between different spin orientations, enhancing quantum tunneling, and weakening the localization of edge-state currents. When the Rashba SOC is weak, electrons with different spins in the valence band move toward higher- and lower-energy regions, leading to an increased overlap of bands and enhancing the conductance in the nanoribbon. Furthermore, when the Rashba SOC exceeds the intrinsic SOC, a tunable band gap emerges near the electron bands. The results provide theoretical insights into spin-orbit coupling effects that may facilitate the design of future spintronic devices.