Role of symmetry mismatch, charge transfer and low dimensionality in the magnetic order of CaMnO3/SrTiO3 ultrathin heterostructures

By means of ab initio calculations, we study the effect charge transfer and symmetry mismatch on magnetic electronic properties CaMnO3 ultrathin films, epitaxially grown SrTiO3 (001). We find that interplay these degrees freedom, together with low dimensionality strain imposed by substrate, changes bulk occupancy Mn eg orbitals, which determines configuration CMO films. A transition from an insulating G-type to a metallic A-type antiferromagnetic is stabilized.