Application of the scattering-rate sum rule to the interplane optical conductivity of high-temperature superconductors: Pseudogap and bilayer effects- art. no. 174506

We use a recently proposed model of the interplane conductivity of high-tem perature superconductors to investigate the "scattering-rate sum rule" intr oduced by Basov and co-workers. We present a derivation of the sum rule. Th e quantal and thermal fluctuations of the order parameter which have been a rgued to produce the observed pseudogap behavior are shown to increase the total integrated "scattering rate" but may either increase or decrease the "quasiparticle" contribution from frequencies greater than twice the superc onducting gap.