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arXiv 1107.2837cond-mat.supr-concond-mat.mes-hall
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介观超导体-正常超导体阵列中零温金属态的研究

Approaching Zero-Temperature Metallic States in Mesoscopic Superconductor-Normal-Superconductor Arrays

Serena Eley, Sarang Gopalakrishnan, Paul M. Goldbart, Nadya Mason

摘要:

放置在普通金属膜上的超导岛系统提供了二维(2D)超导性的可调实现;因此,它们可以阐明关于2D超导体和竞争态的性质的开放问题。特别是,岛系统已被预测表现出零温度金属状态。虽然在某些二维系统中存在这种金属态的证据,但它们的性质还没有得到很好的理解:传统的金属理论无法解释它们,而且它们的性质很难调整。在这里,我们表征的超导转变介观岛阵列系统作为岛的厚度和间距的函数。我们观察到两个过渡过程中的超导性,这两个过渡温度表现出意想不到的强大的抑郁症广泛分布的岛屿。这些凹陷与系统接近零温度金属态是一致的。过渡的性质和它们之间的状态解释使用的现象学模型,涉及稳定的超导性在每个岛上通过一个弱耦合,并从其邻居的反馈。

英文摘要:

Systems of superconducting islands placed on normal metal films offer tunable realizations of two-dimensional (2D) superconductivity; they can thus elucidate open questions regarding the nature of 2D superconductors and competing states. In particular, island systems have been predicted to exhibit zero-temperature metallic states. Although evidence exists for such metallic states in some 2D systems, their character is not well understood: the conventional theory of metals cannot explain them, and their properties are difficult to tune. Here, we characterize the superconducting transitions in mesoscopic island-array systems as a function of island thickness and spacing. We observe two transitions in the progression to superconductivity; both transition temperatures exhibit unexpectedly strong depression for widely spaced islands. These depressions are consistent with the system approaching zero-temperature metallic states. The nature of the transitions and the state between them is explained using a phenomenological model involving the stabilization of superconductivity on each island via a weak coupling to and feedback from its neighbors.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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