Approaching zero-temperature metallic states in mesoscopic superconductor-normal-superconductor arrays

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

Research output: Contribution to journalArticle

Abstract

Systems of superconducting islands placed on normal metal films offer tunable realizations of two-dimensional (2D) superconductivity1,2; 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 states3-5. Although evidence exists for such metallic states in some 2D systems6,7, their character is not well understood: the conventional theory of metals cannot explain them8, and their properties are difficult to tune 7,9. 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, consistent with the system approaching zero-temperature (T=0) metallic states. In particular, the first transition temperature seems to linearly approach T=0 for finite island spacing. The nature of the transitions is explained using a phenomenological model involving the stabilization of superconductivity on each island via a coupling to its neighbours.

Original languageEnglish (US)
Pages (from-to)59-62
Number of pages4
JournalNature Physics
Volume8
Issue number1
DOIs
StatePublished - Jan 1 2012

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Fingerprint Dive into the research topics of 'Approaching zero-temperature metallic states in mesoscopic superconductor-normal-superconductor arrays'. Together they form a unique fingerprint.

  • Cite this