Control of spin in a La(Mn,Zn)AsO alloy by carrier doping

Abstract

The control of spin without magnetic field is one of the challenges in developing spintronic devices. In an attempt to solve this problem, we proposed a novel hypothetical La(Mn_0.5Zn_0.5)AsO alloy from two experimentally synthesized rare earth element transition metal arsenide oxides, i.e. LaMnAsO and LaZnAsO. On the basis of the first-principles calculations with strong-correlated correction, we found that the La(Mn_0.5Zn_0.5)AsO alloy is an antiferromagnetic semiconductor at the ground state, and a bipolar magnetic semiconductor at the ferromagnetic state. Both electron and hole doping in the La(Mn_0.5Zn_0.5)AsO alloy induce the transition from antiferromagnetic to ferromagnetic, as well as semiconductor to half metal. In particular, the spin-polarization direction is switchable depending on the doped carrier type. As carrier doping can be realized easily in experiment by applying a gate voltage, the La(Mn_0.5Zn_0.5)AsO alloy stands as a promising spintronic material to generate and control the spin-polarized carriers with an electric field.