Spin dependent transport behavior in small world networks

Density functional theory (DFT) combined with the non equilibrium Green's function formalism (NEGF) is applied to perform spin polarized transport calculations on small world network (SWN) systems consisting of atomic wires. Including the spin property in SWN structures leads to interesting electrical properties. It is revealed that the emerging spin polarization depends mainly on the SWN geometry given by the asymmetric distribution of loops joining the arbitrary atoms on the main chain. The spin-asymmetric behavior which yields the spin polarization is found to be largely determined by those loops which are close to the electrodes. However, spin polarization may vanish for a specific SWN structure due to symmetry.