Effects of interfacial electron transfer on the magnetic structure of SrMnO3 in LaAlO3/SrMnO3 heterostructures

Electronic and magnetic structures of LaAlO3/SrMnO3 (LAO/SMO) heterostructures were studied by first-principles calculations. Two-dimensional electron gas is predicted to occur at the interface of the two band insulators, due to electron transfer driven by the interface polar discontinuity. Although SMO is a G-type antiferromagetic in bulk, the SMO layers close to the LAO/SMO interface show different types of magnetic orders due to the electrostatic electron doping into Mn eg orbitals. The modulation on the magnetic structure in interfacial SMO is discussed in terms of the doping concentration as a function of LAO overlayer thickness.