Polarization dependence of the electronic Raman spectra of Ca-substituted YBCO single crystals: As a probe of s-wave mixing in the superconducting gap

Electronic and phononic Raman scattering in detwinnedYBa2Cu3O6.95andBakr1, Schnyder2, Klam3 et al. 2009Phys. Rev. B343340View full textAdd to dashboardCite

“…The best agreement with the Raman data was obtained by model calculations based on admixtures of 10% and 15% Ϯ 5% s-wave contribution for YBa 2 Cu 3 O 6.95 and Y 0.85 Ca 0.15 Ba 2 Cu 3 O 6.95 , respectively. This agrees with values obtained by other experimental methods [3][4][5][6][7][8] and confirms the previously observed trend 4 of an increase in the s-wave contribution with increasing doping level. Our data do not show evidence of the previously reported 51 unusual quantum interference between electronic Raman scattering from planes and chains in overdoped Y 1−x Ca x Ba 2 Cu 3 O 7−␦ .…”

“…A more general trend of increasing s-wave admixture with increasing doping level has also been reported. [3][4][5][6] In YBa 2 Cu 3 O 7−␦ ͑YBCO 7−␦ ͒, such an admixture has been confirmed by angle-resolved photoemission spectroscopy ͑ARPES͒ ͑Ref. 7͒ and flux measurements on Josephson junctions.…”

Fallacies on pairing symmetry and intrinsic electronic Raman spectrum in high-Tc cuprate superconductors

“…2a, 2b, and 2d) in the same context are also not intrinsic. Moreover, in previous researches, a similar curve on B 1g for an overdoped Ca-Y BCO crystal [17] and a nonlinear curve at B 2g in an optimally doped La 1.85 Sr 0.15 CuO 4 crystal [18] were observed. Instead, the nonlinear behavior denying d x 2 −y 2wave symmetry indicates that the super gaps ( Figs.…”

Superconducting gap of overdoped Tl2Ba2CuO6+δ observed by Raman scattering

“…For Y 123 single crystals, it is suggested that the dramatic reduction for B 1g pair breaking peak energy at the doping level p~0.19 may be related to a quantum critical point (QCP) [16]. …”