Particle-hole symmetry breaking in the pseudogap state of Pb_(0.55)Bi_(1.5)Sr_(1.6)La_(0.4)CuO_(6+δ): A quantum chemical perspective

摘要

Two Bi2201 model systems are employed to demonstrate how, beside the Cu-O σ band, a second band of purely O 2pπ character can be made to cross the Fermi level due to its sensitivity to the local crystal field. This result is employed to explain the particle-hole symmetry breaking across the pseudogap recently reported by Shen and co-workers [see M. Hashimoto et al, Nature Phys. 6, 414 (2010).]. Support for a two-bands-on-a-checkerboard candidate mechanism for high-T_c superconductivity is claimed. Analysis based on band structures, partial density of states, and sum over states densities scanning-tunneling-microscopy-type images is provided.