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Isotope effect in the presence of a pseudogap

Thomas Dahm
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Abstract

We investigate the question whether the unusual doping dependence of the isotope exponent observed in underdoped high-Tc superconductors might be related to another unusual phenomenon observed in these systems: the pseudogap phenomenon. Within different approximations we study the influence of a phenomenological pseudogap on the isotope exponent and find that it generally strongly increases the isotope exponent, in qualitative agreement with experiments on underdoped high-Tc compounds. This result is stable against strong-coupling self-energy corrections and also holds for recently proposed spinfluctuation exchange models, if a weak additional electron-phonon coupling is considered.

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Thomas Dahm. 1999-11-09. Isotope effect in the presence of a pseudogap. https://doi.org/10.1103/physrevb.61.6381

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