Critical currents and the Ambegaokar-Baratoff to Ginsburg-Landau crossover in granular superconductors

J. L. Cardoso; P. Pereyra

doi:10.1103/PhysRevB.61.6360

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Critical currents and the Ambegaokar-Baratoff to Ginsburg-Landau crossover in granular superconductors

J. L. Cardoso, P. Pereyra

DOI 10.1103/PhysRevB.61.6360 · Physical Review B

T1

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Abstract

A simple expression for the transport critical current, which describes rather well the Ambegaokar-Baratoff (A-B) to Ginsburg-Landau (G-L) crossover, is obtained from an elementary analysis of a Josephson junction subject to external magnetic fields within the Ginsburg-Landau theory. We show that the order parameter in the intergrain region depends crucially on the interplay of two characteristic lengths: the superconducting coherence length ξ∝(1−T/Tc)−1/2 and the junction-induced superconducting decoherence length ζq∝(1−T/Tc)−α. Data for the transport critical current in granular YBCO samples are presented, and the A-B to G-L crossovers successfully described.

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
YBCO Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	92	Pressure not reported	unknown
NbN Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	unknown