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arXiv · 0805.1281

Origin of spatial variation of pairing gap in Bi-based high-Tc cuprates

M. Mori·G. Khaliullin·T. Tohyama·S. Maekawa
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Abstract

Recently, scanning tunneling microscopy on Bi-2212 cuprate superconductor has revealed a spatial variation of the energy gap that is directly correlated with a modulation of the apical oxygen position. We identify two mechanisms by which out-of-plane oxygens can modulate the pairing interaction within the CuO_2 layer: a covalency between the x^2-y^2 band and apical p-orbital, and a screening of correlation U by apical oxygen polarization. Both effects strongly depend on the apical oxygen position and their cooperative action explains the experiment.

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M. Mori, G. Khaliullin, T. Tohyama, S. Maekawa. 2008-11-10. Origin of spatial variation of pairing gap in Bi-based high-Tc cuprates. https://doi.org/10.1103/physrevlett.101.247003

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