Light-scattering study of the superconducting energy gap in YBa2Cu3O7 single crystals

Abstract
Raman scattering experiments have been performed on single-crystal samples of YBa2 Cu3 O7 in order to investigate superconducting gap excitations. The electronic contribution to the total scattering intensity can be fitted well by a theoretical model of light scattering from quasiparticle pairs. Depending on the measuring symmetry, mean gap energies are found ranging from 3.0 to 5.5 kBTc.