Azulene-like molecular devices with high spin filtering, strong spin rectifying, and giant magnetoresistance effects

Abstract By using the nonequilibrium Green's function method combined with density functional theory, we investigate the spin transport properties of an azulene-like molecule sandwiched between two ferromagnetic zigzag graphene nanoribbon (ZGNR) electrodes. The results show that the width of electrodes and the magnetization configurations of electrodes are critical to spin transport. By tuning the spin configurations of ZGNR electrodes, excellent spin filtering, spin rectifying, and giant magnetoresistance behaviors can be obtained simultaneously in devices with 4-ZGNR electrodes. Analysis of symmetric of Bloch wave functions, spin resolved band structures of the electrodes with applied bias, transmission spectra, as well as the projected density of states reveals the mechanism of these intriguing properties. These results might be useful in the design of high performance multifunctional spintronic devices.