Electronic, magnetic and transport properties of zigzag silicene nanoribbon adsorbed with Cu atom: A first-principles calculation

Abstract

Abstract This paper aims to provide a detailed analysis of the electronic, magnetic and spin-dependent transport properties of Cu-adsorbed zigzag silicene nanoribbons within the density functional theory framework. The possibility of diffusion between different stable positions is studied by Nudge Elastic Band (NEB) method. As to zigzag graphene nanoribbons, the center of nearest hexagonal to the edge is the most favorable site for adsorbing Cu atom. Total energy analysis for spin-polarized calculations indicates that the antiferromagnetic (AFM) state is the magnetic ground state of zigzag silicene nanoribbons whereas adding the Cu adatom on the near edge yields ferromagnetic (FM) state with the total magnetization about 0.98 μ B . As a consequence of charge transfer from Si atoms to Cu, the spin distribution symmetry of the edges is broken and the spin magnetic moment is considerably localized on the edge with no adsorption. Further verification of the electronic properties may be obtained through investigating the conductivity behavior of the device using the current-voltage (I-V) characteristics based on density functional theory with non-equilibrium Green’s function included. Although the spin-up current increases with the bias monotonically, a spin negative different resistance phenomenon is observed for spin-down electrons. Additionally, spin-up transmission shows higher values in comparison with that for spin-down in bias window which leads to the higher current. The results hold promising applications for future nano-electronics and spintronic devices.