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The optimal inhomogeneity for superconductivity

E. Arrigoni·S. A. Kivelson
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Abstract

We study the effect of nonuniform transverse couplings on a quasi-one dimensional superconductor. We show that inhomogeneous couplings quite generally increase the superconducting (pairing) gap relative to the uniform system, but that beyond an ``optimal'' degree of inhomogeneity, they lead to a suppression of the tendency to phase coherence. The optimal conditions for superconductivity are derived. We also show that a {\it delocalized}, spin-gapped phase is stable against weak disorder in a four-leg-ladder with moderate repulsive interactions.

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E. Arrigoni, S. A. Kivelson. 2002-12-11. The optimal inhomogeneity for superconductivity. https://doi.org/10.1103/physrevb.68.180503

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