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

Abstract

Certain significant fallacies are involved in discussions of the high-[Formula: see text] mechanism unsolved for over 30 years in cuprate superconductors. These fallacies are explored with the aim of unraveling this mechanism. Moreover, using polarized electronic Raman scattering in inhomogeneous underdoped cuprate superconductors, the intrinsic nonlinear Raman spectrum is obtained by subtracting the pseudogap characteristic of a nonlinear from the linear Raman spectrum measured in the [Formula: see text] mode of the node area below the critical temperature. The intrinsic nonlinear behavior implies the existence of the nodal superconducting gap denying [Formula: see text]-wave pairing symmetry. An origin of the nodal superconducting gap is discussed.