Spin transport properties and spin logic gates in manganese phthalocyanine-based molecular combinational circuits

Abstract

Spintronic devices are very important for futuristic information technology. By using nonequilibrium Green's functions in combination with density functional theory, we investigate the spin transport properties of manganese phthalocyanine (MnPc)-based spintronic devices constructed from MnPc connected in series or parallel with single-walled carbon nanotube electrodes. Our calculations show that MnPc has a large transmission around the Fermi level, which is dominated by the spin-down molecular orbitals even when the magnetization direction of the Mn atom in MnPc molecules is spin up. Series and parallel devices have very different current–voltage relationships, which can be attributed to the magnetic coupling between two Mn atoms. Moreover, we propose a set of spin logic gates, in which spin-polarized current can be manipulated by the magnetic configuration of the Mn atoms. These spin logic gates demonstrate their promising applications in designing spintronic integrated circuits on the atomic scale.