Perfect dual spin filtering effect and large magnetoresistance in all-carbon devices based on C18 cyclo molecule from first principles

Abstract

The carbon-based nanomaterial would push silicon aside and create a post- complementary metal oxide semiconductor world. In this work, we proposed and theoretically investigated an all-carbon spintronic device composed of C18 cyclo molecule and two zigzag graphene nanoribbon (ZGNR) electrodes with two different sturdy connection modes. It is found that both structures have similar excellent spin-dependent properties. Adjusting the magnetization configuration of two electrodes to be anti-parallel, electrons in different spin states are filtered unidirectionally according to the sign of the applied bias voltage. The molecular junction exhibits a perfect dual spin filtering effect. Moreover, a huge magneto-resistance ratio was found in our propose junctions. The matching of symmetry type of the spin-polarized states in two ZGNR electrodes, as well as the states of C18 in central region plays an important role in the occurrence of these effects.