Magnetism, conductivity, and orbital order in (LaMnO3)2n/(SrMnO3)n superlattices

The modulation of charge density and spin order in (LaMnO3)(2n)/(SrMnO3)(n) (n=1-4) superlattices is studied via Monte Carlo simulations of the double-exchange model. G-type antiferromagnetic barriers in the SrMnO3 regions with low charge density are found to separate ferromagnetic LaMnO3 layers with high charge density. A metal-insulator transition with increasing n is observed in the direction perpendicular to the interfaces. Our simulations provide insight into how disorder-induced localization may cause the metal-insulator transition occurring at n=3 in experiments.