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arXiv · 0809.2919

Effect of dopant atoms on local superexchange in cuprate superconductors: a perturbative treatment

Kateryna Foyevtsova·Roser Valenti·P. J. Hirschfeld
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Abstract

Recent scanning tunneling spectroscopy experiments have provided evidence that dopant impurities in high- Tc superconductors can strongly modify the electronic structure of the CuO2 planes nearby, and possibly influence the pairing. To investigate this connection, we calculate the local magnetic superexchange J between Cu ions in the presence of dopants within the framework of the three-band Hubbard model, up to fifth-order in perturbation theory. We demonstrate that the sign of the change in J depends on the relative dopant-induced spatial variation of the atomic levels in the CuO2 plane, contrary to results obtained within the one-band Hubbard model. We discuss some realistic cases and their relevance for theories of the pairing mechanism in the cuprates

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Kateryna Foyevtsova, Roser Valenti, P. J. Hirschfeld. 2009-04-21. Effect of dopant atoms on local superexchange in cuprate superconductors: a perturbative treatment. https://doi.org/10.1103/physrevb.79.144424

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