Calculations of the quasiparticle-lifetime broadening 1/τ, 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 intra–van Hove–singularity scattering without the intervention of nesting.

• Received 19 July 1991

DOI:https://doi.org/10.1103/PhysRevB.45.5714