Quasiparticles in high temperature superconductors: consistency of angle resolved photoemission and optical conductivity

TL;DR

This paper investigates the consistency between angle-resolved photoemission and optical conductivity experiments in high-temperature superconductors, deriving formulas to relate measured quantities and analyzing their implications for understanding quasiparticle behavior.

Contribution

It derives formulas linking photoemission and optical measurements under specific self-energy assumptions, clarifying their interpretation in high-Tc superconductors.

Findings

Total self energy from photoemission cannot be a transport scattering rate.

Inelastic part of self energy may be interpreted as a transport scattering rate with Landau effects.

Formulas are applicable to optimally and overdoped Bi-2212 superconductors.

Abstract

The consistency of angle-resolved photoemission and optical conductivity experiments on high temperature superconductors is examined. In the limit (apparently consistent with angle-resolved photoemission data) of an electron self energy with a weak momentum dependence and a strong frequency dependence formulae are derived which directly related quantities measured in the two experiments. Application of the formuale to optimally and overdoped $Bi_{2}Ca_{2}SrCu_{2}O_{8+\delta}$ shows that the total self energy inferred from photoemission measurements cannot be interpreted as a transport scattering rate (in agreement with work of Varma and Abrahams), but that the inelastic part may be so interpreted, if Landau parameter effects are non-negligible.