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