ON THE CHARACTERISTIC LENGTHS OF THE HIGH-TC OXIDE SUPERCONDUCTORS

We discuss the fundamental characteristic lengths, namely ξ0the zero temperature coherence length, λLthe London penetration depth, and l the carrier mean free path, for the oxide high Tcsuperconductors in relation to the latest experimental measurements. We examine theoretically why ξ0is so small and argue that its smallness is independent of the nature of the pairing mechanism of superconductivity. We also compare various measurements from the point of view of Pippard’s theory for both the normal and the superconducting states respectively. Several questions are posed by these interpretations of the experimental data. © 1992, Taylor & Francis Group, LLC. All rights reserved.