Frustrated kinetic energy, the optical sum rule, and the mechanism of superconductivity

TL;DR

This paper examines how changes in electronic kinetic energy perpendicular to CuO-planes relate to superconductivity, showing consistency with optical and penetration depth measurements through a rigorous sum rule analysis.

Contribution

It provides a theoretical analysis linking kinetic energy changes to superconductivity, supported by optical and penetration depth data, emphasizing the role of the $c$-axis sum rule.

Findings

Kinetic energy change is a significant part of the condensation energy.

The theory aligns with recent optical measurements.

The $c$-axis sum rule is crucial for understanding superconductivity mechanisms.

Abstract

The theory that the change of the electronic kinetic energy in a direction perpendicular to the CuO-planes in high-temperature superconductors is a substantial fraction of the condensation energy is examined. It is argued that the consequences of this theory based on a rigorous $c$-axis conductivity sum rule are consistent with recent optical and penetration depth measurements.