Low-Energy Quasiparticles in Cuprate Superconductors: A Quantitative Analysis

TL;DR

This paper provides a quantitative analysis of low-energy quasiparticles in cuprate superconductors, showing they significantly suppress superfluid density and align with Fermi-liquid theory predictions, based on thermal conductivity and photoemission data.

Contribution

It offers the first comprehensive, parameter-free quantitative analysis linking quasiparticle behavior to thermodynamic suppression of superfluid density in cuprates.

Findings

Residual linear thermal conductivity matches Fermi-liquid theory.

Quasiparticles are a major factor in superfluid density suppression.

Analysis applies to Bi-2212 and YBCO cuprates.

Abstract

A residual linear term is observed in the thermal conductivity of optimally-doped Bi-2212 at very low temperatures whose magnitude is in excellent agreement with the value expected from Fermi-liquid theory and the d-wave energy spectrum measured by photoemission spectroscopy, with no adjustable parameters. This solid basis allows us to make a quantitative analysis of thermodynamic properties at low temperature and establish that thermally-excited quasiparticles are a significant, perhaps even the dominant mechanism in suppressing the superfluid density in cuprate superconductors Bi-2212 and YBCO.