Spin-filtering, giant magnetoresistance, negative differential resistance effects and spin logic gate in P_2TA-O_2-based molecular junction with different transition metal atoms

摘要

By applying the density functional theory and the nonequilibrium Green's function formalism, we investigate the spin-polarized transport properties of oligoporphyrin molecule (P2TA-O2) with different transition metal atoms (Cr, Mn, Fe, Co). The results show that the spin-polarized transport properties can be effectively tuned by changing the transition metal atoms, and the Mn-P2TA-O2system can exhibit high-efficiency spin-filtering, giant magnetoresistance and low-bias voltage negative differential resistance effects by tuning the external magnetic field. These effects are elucidated in terms of the spin-resolved transmission spectrum, the projected density of states and the spatial distribution of molecular orbitals around the Fermi level. Based on these interesting effects, a spin AND logic gate is realized. The results indicate that the Mn-P2TA-O2system holds great potential in designing spintronic molecular devices.