Two-lifetime model for the cuprates revisited

TL;DR

This paper introduces a two-lifetime phenomenological model for cuprate superconductors that explains key ARPES spectral features and distinguishes between different scattering mechanisms, advancing understanding of their strange-metal state.

Contribution

It proposes a novel two-lifetime model that explains ARPES data and differentiates forward from large-angle scattering in cuprates.

Findings

The model fits low-energy ARPES spectra well.

It distinguishes forward scattering from large-angle scattering.

It provides estimates of the gap function away from the Fermi surface.

Abstract

Several models of the strange-metal state of the cuprate superconductors postulate the existence of strong inelastic forward scattering of the electrons, but direct evidence of such scattering is missing. Here we show that angle-resolved photoemission spectroscopy (ARPES) provides a unique tool which can address this issue. We propose a two-lifetime phenomenological model of the superconducting state of the cuprates and we show that it explains several salient low-energy features of the measured ARPES spectra. The model enables discrimination between forward- and large-angle scattering and, in addition, gives access to the magnitude of the gap function away from the Fermi surface.