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arXiv · 2107.01567

Superconducting insulators and localization of Cooper pairs

Konstantin Yu. Arutyunov·Janne S. Lehtinen·Alexey Radkevich·Andrew G. Semenov·Andrei D. Zaikin
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Abstract

Rapid miniaturization of electronic devices and circuits demands profound understanding of fluctuation phenomena at the nanoscale. Superconducting nanowires -- serving as important building blocks for such devices -- may seriously suffer from fluctuations which tend to destroy long-range order and suppress superconductivity. In particular, quantum phase slips (QPS) proliferating at low temperatures may turn a quasi-one-dimensional superconductor into a resistor or an insulator. Here, we introduce a physical concept of QPS-controlled localization of Cooper pairs that may occur even in uniform nanowires without any dielectric barriers being a fundamental manifestation of the flux-charge duality in superconductors. We demonstrate -- both experimentally and theoretically -- that deep in the "insulating" state such nanowires actually exhibit non-trivial superposition of superconductivity and weak Coulomb blockade of Cooper pairs generated by quantum tunneling of magnetic fluxons across the wire.

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Konstantin Yu. Arutyunov, Janne S. Lehtinen, Alexey Radkevich, Andrew G. Semenov, Andrei D. Zaikin. 2021-07-04. Superconducting insulators and localization of Cooper pairs. https://doi.org/10.1038/s42005-021-00648-7

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