Electric Field Dependence of Junction Paraconductivity

抄録

Effect of electric field on the paraconductivity σ₁ of Pb–Al₂O₃–Al junctions has been investigated, and a phenomenological analysis has been performed on the basis of Ferrell’s theory and the Langevin equation of the superconducting order parameter. The junction paraconductivity observed at temperatures slightly the transition temperature of the aluminum film is found to decrease with increasing the electric field E applied to the aluminum film parallel to converge rapidly to a temperature-independent asymptote proportional to E^−p where p=1.5±0.2. This asymptote at high fields is successfully derived with p=5⁄3 from the present phenomenological theory, whereas a discrepancy is found in the intermediate field region, where theory, predicts that σ₁ is inversely proportional to E but the observed values converge much rapidly to the asymptote.