Electronic structure of buried LaNiO3 layers in (111)-oriented   LaNiO3/LaMnO3 superlattices probed by soft x-ray ARPES
  Taking advantage of the large electron escape depth of soft x-ray angle resolved photoemission spectroscopy we report electronic structure measurements of (111)-oriented [LaNiO3/LaMnO3] superlattices and LaNiO3 epitaxial films. For thin films we observe a 3D Fermi surface with an electron pocket at the Brillouin zone center and hole pockets at the zone vertices. Superlattices with thick nickelate layers present a similar electronic structure. However, as the thickness of the LaNiO3 is reduced the superlattices become insulating. These heterostructures do not show a marked redistribution of spectral weight in momentum space but exhibit a pseudogap of 50 meV. 
F. Y. Bruno, M. Gibert, S. McKeown Walker, O.E. Peil, A. de la Torre,   S. Ricc\`o, Z. Wang, S. Catalano, A. Tamai, F. Bisti...
cond-mat.mtrl-sci