Spatial inhomogeneity and strong correlation physics: a dynamical mean   field study of a model Mott-insulator/band-insulator heterostructure
  We use the dynamical mean field method to investigate electronic properties of heterostructures in which finite number of Mott-insulator layers are embedded in a spatially infinite band-insulator. The evolution of the correlation effects with the number of Mott insulating layers and with position in the heterostructure is determined, and the optical conductivity is computed. It is shown that the heterostructures are generally metallic, with moderately renormalized bands of quasiparticles appearing at the interface between the correlated and uncorrelated regions. 
Satoshi Okamoto and Andrew J. Millis