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