Superfluid Flow Past an Array of Scatterers

Abstract

We consider a model of nonlinear superfluid flow past a periodic array of point-like scatterers in one dimension. An application of this model is the determination of the critical current of a Josephson array in a regime appropriate to a Ginzburg-Landau formulation. Here, the array consists of short normal-metal regions, in the presence of a Hartree electron-electron interaction, and embedded within a one-dimensional superconducting wire near its critical temperature, $Tc$. We predict the critical current to depend linearly as $A(Tc-T)$, while the coefficient $A$ depends sensitively on the sizes of the superconducting and normal-metal regions and the strength and sign of the Hartree interaction. In the case of an attractive interaction, we find a further feature: the critical current vanishes linearly at some temperature $T\ast$ less than $Tc$, as well as at $Tc$ itself. We rule out a simple explanation for the zero value of the critical current, at this temperature $T\ast$, in terms of order parameter fluctuations at low frequencies.

23 pages, REVTEX, six eps-figures included; submitted to PRB

References in corpus (2)

• Influence of Quantum Fluctuations on Phase Coherent Andreev Tunneling
• Quantum Nucleation of Phase Slips in a 1d Model of a Superfluid

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