Electronic Raman scattering in high-Tc superconductors: A probe of dx2-y2 pairing

Abstract

New measurements on the high-temperature superconductor ${\mathrm{Bi}}_2$ ${\mathrm{Sr}}_2$ ${\mathrm{CaCu}}_2$ ${\mathrm{O}}_8$ are interpreted and found to be in quantitative agreement with a theory for electronic Raman scattering in superconductors with ${\mathit{d}}_{\mathit{x}}^2$-${\mathit{y}}^2$ pairing symmetry. The theory explains in a natural way, why the shape of the scattering intensity, as well as its change with temperature can be polarization (symmetry) dependent and hence resolves a controversy in previous interpretations of data on the electronic Raman effect.