Photoirradiation and electric field tunable spin/charge transport in a Y-shaped silicene nanojunction

Abstract

In this work, we propose a Y-shaped nanojunction consisting of zigzag silicene nanoribbons (ZSNRs), and study the charge/spin transport based on a tight-binding approach, Landauer formalism and non-equilibrium Green’s function method. The topological states with various edge modes, such as quantum spin Hall insulator, quantum Hall insulator and band insulator, can all be engineered by the electric field and photoirradiation in ZSNRs. Through tuning the edge states of the two output terminals, three types of charge/spin router can be achieved in the present nanojunction. The first is a charge current switcher, which switches the charge current from one output terminal to the other. The second is a spin current router, which shunts the spin-up and spin-down current into different output terminals. The last is a spin filter, which filters the spin-polarized current into a specific output terminal. The proposed Y-shaped nanojunction may have potential applications in electronic and spintronic nanodevices in the future.