Stable Intrinsic Long Range Antiferromagnetic Coupling in Dilutely V Doped Chalcopyrite

A stable and long-range antiferromagnetic (AFM) coupling without charge carrier mediators has been searched for a long time, but the existence of this kind of coupling is still lacking. Based on first principle calculations, we systematically study carrier free long-range AFM coupling in four transition metal chalcopyrite systems: ABTe_2 (A = Cu or Ag, B = Ga or In) in the dilute doping case. The AFM coupling is mainly due to the p–d coupling and electron redistribution along the interacting chains. The relatively small energy difference between p and d orbitals, as well as between dopants and atoms in the middle of the chain can enhance the stability of long-range AFM configurations. A multi-band Hubbard model is proposed to provide fundamental understanding of long-range AFM coupling.