Eur. Phys. J. B 5, 495-503 (1998)
https://doi.org/10.1007/s100510050471

d+s wave superconductivity: Analysis of the electronic Raman data of YBa₂Cu₃O and other cuprates^*

¹ Walther Meissner Institut, Bayerische Akademie des Wissenschaften, 85748 Garching, Germany
² Physique des Solides, Université Paris-sud, 91400 Orsay, France
³ Department of Physics and Astronomy, U.S.C., Los Angeles, CA 90089-0484, USA
⁴ Departement de Physique de la Matière Condensée, Université de Genève, 24 quai E. Ansermet, 1211 Genève 4, Switzerland

Corresponding author: ^a zazie@hprib.lps.u-psud.fr

Received: 3 March 1998
Accepted: 30 April 1998
Published online: 15 October 1998

Abstract

After briefly recalling the d+s model valid for some anisotropic high T_c superconductors, we present a theory of electronic Raman spectra in that model and then compare it with new experimental data obtained for an overdoped Y123 single crystal. The d+s model appears to describe satisfactorily the experimental results, indicating a possible doping dependence of the mixing ratio. We note that the Raman spectrum of the overdoped Bi2212 could also be accounted for by the d+s superconductivity model. The case of Hg1212 (or Hg1223) is reexamined. It appears that the spontaneous breakdown of d-wave symmetry may be rather universal in high T_c cuprates.