  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.
