Twist controlled Spin-transport across Phosphorene/Nickel (111) Spinterfaces

The electron's spin serves as a crucial information carrier in spintronic devices, which is extremely important for the growth of quantum computing applications, high-density data storage, high-frequency devices, magnetoelectrics, etc. Phosphorene [4], a novel 2D semiconductor, offers significant potential for nanoelectronic, optoelectronic, and spintronic applications due to its inherent bandgap, high mobility, excellent spin diffusion and relaxation time [3], and ambipolar nature. In this study, we explored the transmission probability of spin carriers from a Ni electrode into phosphorene using first principles-based density functional theory (DFT) in conjunction with the non-equilibrium Green’s function (NEGF) method. By increasing the number of phosphorene layers (N = 1, 2, 3) and incorporating a twist mechanism, we significantly enhanced the efficiency of spin injection from Ni to the phosphorene layer. We systematically examined the structural, electronic, and magnetic characteristics of the P/Ni(111) junction. On the Ni surface, the mono-, bi-, and tri-layers of phosphorene exhibited metallic behavior. The electronic bands near the Fermi level varied with the twisted angles and observed ohmic contact between phosphorene and the Ni(111) surface. The majority carrier was spin-down at the Fermi level, with an induced magnetic moment of -0.009 μ_B in phosphorene and an enhanced magnetic moment in the Ni atom. Moreover, the current-voltage characteristics displayed negative differential resistance (NDR effects), with peak-to-valley ratio (PVR) and sharpness factor (S_E) varying with the twisted angle. The efficiency of spin injection increased with the number of phosphorene layers, and twisting modified the spin injection efficiency, resulting in an increase of up to 60%. These findings offer valuable theoretical insights into the transmission of spin carriers within phosphorene layers on a magnetic substrate, suggesting a novel approach for designing spintronic devices utilizing phosphorene.