Sum Rule Anomaly from Suppression of Inelastic Scattering in the Superconducting State

TL;DR

This paper proposes a model where a sharp decrease in elastic scattering rate below Tc explains the observed decrease in kinetic energy in superconductors, linking it to experimental microwave conductivity data.

Contribution

It introduces a simple phenomenological model connecting scattering rate suppression to kinetic energy reduction in superconductors.

Findings

Decrease in kinetic energy explained by reduced elastic scattering below Tc

Model aligns with microwave conductivity observations

Suggests broader experimental validation across high Tc materials

Abstract

In the conventional BCS description of a superconductor the kinetic energy increases in the superconducting state. We describe the observed decrease in kinetic energy by adopting a simple model of electrons whose elastic scattering rate undergoes a sharp decrease as the temperature is lowered below Tc. This phenomenology has been suggested by other experiments, particularly microwave conductivity. We find that such a decrease accounts for the observed increase; a study of these different phenomena over a wide range of high Tc materials would confirm this correlation.