Electronic Structure of Ladder Cuprates
  We study the electronic structure of the ladder compounds (SrCa)CuO 14-24-41 and SrCuO 123. LDA calculations for both give similar Cu 3d-bands near the Fermi energy. The hopping parameters estimated by fitting LDA energy bands show a strong anisotropy between the t_perp t_par intra-ladder hopping and small inter-ladder hopping. A downfolding method shows that this anisotropy arises from the ladder structure.The conductivity perpendicular to the ladders is computed assuming incoherent tunneling giving a value close to experiment. 
T. F. A. Muller (1), V. Anisimov (1), T. M. Rice (1), I. Dasgupta (2),   T. Saha-Dasgupta (2) ((1) ETH-Zurich, (2) Max-Planc...