International Journal of Modern Physics B Vol. 27, No. 19 (2013) 1330013 (28 pages) c  World Scientific Publishing Company DOI: 10.1142/S0217979213300132 INDUCED MAGNETISM AT OXIDE INTERFACES JACOBO SANTAMARIA * , JAVIER GARCIA-BARRIOCANAL, ZOUHAIR SEFRIOUI and CARLOS LEON GFMC, Departamento Fisica Aplicada III, Universidad Complutense Madrid 28040 Madrid, Spain * jacsan@fis.ucm.es Received 13 June 2013 Accepted 14 June 2013 Published 3 July 2013 Interfaces between correlated oxides are attracting great interest. Electron correlations give rise to novel forms of couplings between electronic ground states at both sides of the interface. The bonding discontinuity at the interface between magnetic and nonmag- netic oxides is at the origin of a form of low dimensional magnetism in the otherwise nonmagnetic material. Its origin is the splitting of its bands due to the hybridization with the exchange split bands of the magnetic material. This induced magnetism could find interesting functionalities in devices with operation controlled by the interface such as tunnel or field effect devices of interest in spintronics. Keywords : Oxide interfaces; magnetism; superconductivity. PACS numbers: 73.20.-r, 75.70.Ch, 74.78.Fk 1. Introduction Complex transition metal oxides are a wide family of materials which contain elements with incomplete d shells, what gives rise to different forms of magnetic interactions. Almost every electronic or lattice groundstate of solid matter can be found including superconductivity, ferromagnetism, antiferromagnetism, ferroelec- tricity, multiferroicity etc. 1,2 Distinct members of this class of materials are high T c superconductors and colossal magnetoresistance manganites which have gathered one of the strongest research efforts in the history of science in terms of number and impact of research articles and number of researchers involved. Many complex oxides share a common perovskite structure where the basic building block is the oxygen octahedron surrounding the transition metal ion. The strong crystal (elec- tric) field generated by the oxygen ions act on the otherwise 5 fold degenerate d levels of the transition metal ion splitting them in e g and t 2g levels which are double and triple degenerate respectively. d orbitals are directional and their overlap me- diated by the oxygen p orbitals is weak what yields the narrow d bands with large 1330013-1 Int. J. Mod. Phys. B 2013.27. Downloaded from www.worldscientific.com by 207.97.226.128 on 06/22/14. For personal use only.