Differences Between Hole and Electron Doping of a Two-Leg CuO Ladder
  Here we report results of a density-matrix-renormalization-group (DMRG) calculation of the charge, spin, and pairing properties of a two-leg CuO Hubbard ladder. The outer oxygen atoms as well as the rung and leg oxygen atoms are included along with near-neighbor and oxygen-hopping matrix elements. This system allows us to study the effects of hole and electron doping on a system which is a charge transfer insulator at a filling of one hole per Cu and exhibits power law, d-wave-like pairing correlations when doped. In particular, we focus on the differences between doping with holes or electrons. 
S. Nishimoto (1), E. Jeckelmann (1), and D.J. Scalapino (2) ((1)   University of Marburg, Germany, (2) University of Califor...