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About the influence of the square-root van Hove singularity on the critical temperature of overdoped high-temperature superconductors

Conference · · International Journal of Modern Physics B
OSTI ID:6442810
;  [1]
  1. National Academy of Sciences of Ukraine, Kiev (Ukraine). Inst. of Physics
It is shown that the square-root van Hove singularity in the density of states [nu](E[sub F]) [approximately] (E[sub F] [minus] E[sub 0])[sup [minus]1/2], associated with the extended saddle-point singularities in the electron spectra of the cuprates, leads to a nonmonotonic dependence of the critical temperature [Tc] on the position of the Fermi level E[sub F] with respect to the bottom E[sub 0] of the saddle. As a result of cancellation of the divergency of [nu](E[sub F]) in the electron-electron coupling constant, renormalized due to the account of the strong coupling effects, [Tc] approaches zero in the limit E[sub F] [r arrow] E[sub 0]. This result contrasts that of the weak coupling approximation, which gives a finite value of [Tc] for E[sub F] [r arrow] E[sub 0]. The [Tc] on the concentration of doped holes, obtained in the strong coupling approximation, agrees qualitatively with the experimental data for the overdoped cuprate metal-oxides.
OSTI ID:
6442810
Report Number(s):
CONF-980291--
Conference Information:
Journal Name: International Journal of Modern Physics B Journal Volume: 12:29-31
Country of Publication:
United States
Language:
English