New p- and n-type ferromagnetic semiconductors: Cr-doped BaZn2As2

摘要

We find new ferromagnetic semiconductors, Cr-doped BaZn₂As₂, by employing a combined method of the density functional theory and the quantum Monte Carlo simulation. Due to a narrow band gap of 0.2 eV in host BaZn₂As₂ and the different hybridization of 3d orbitals of Cr impurity, the impurity bound states have been induced both below the top of valence band and above the bottom of conduction band. The long-range ferromagnetic coupling between Cr impurities is obtained with both p- and n-type carriers.