Evidence for the van Hove scenario in high-temperature superconductivity from quasiparticle-lifetime broadening

Calculations of the quasiparticle-lifetime broadening 1/, both for idealized and realistic models of the band structure, show a large lifetime broadening from electron-electron scattering, with the characteristic linear dependence on energy from the Fermi energy seen in high-temperature superconductors, provided that the Fermi level lies near the van Hove singularity in the quasi-two-dimensional band structure. The effect comes from intravan Hovesingularity scattering without the intervention of nesting. © 1992 The American Physical Society.