Metallic characteristics in superlattices composed of insulators,   NdMnO3/SrMnO3/LaMnO3
  We report on the electronic properties of superlattices composed of three different antiferromagnetic insulators, NdMnO3/SrMnO3/LaMnO3 grown on SrTiO3 substrates. Photoemission spectra obtained by tuning the x-ray energy at the Mn 2p -> 3d edge show a Fermi cut-off, indicating metallic behavior mainly originating from Mn e_g electrons. Furthermore, the density of states near the Fermi energy and the magnetization obey a similar temperature dependence, suggesting a correlation between the spin and charge degrees of freedom at the interfaces of these oxides. 
J. W. Seo, B. T. Phan, J. Lee, H.-D. Kim, and C. Panagopoulos
cond-mat.str-el cond-mat.mtrl-sci