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Communication Dans Un Congrès Année : 2019

How small a superconductor can be?

Alexandre Assouline
  • Fonction : Auteur
Christophe David
  • Fonction : Auteur
Guillemin Rodary
J.-C. Girard

Résumé

In 1959, physicist P.W. Anderson conjectured that superconductivity can exist only in objects where superconducting gap energy is larger than its electronic energy level spacing. In our work [1,2], we were able to address this limit in single nanoparticles of various sizes without suffering from inverse proximity effect. Here we report on a scanning tunneling spectroscopy study of superconducting lead nanocrystals grown on the (110) surface of InAs (figure 1). The electronic transmission at the InAs/nanocrystal interface is weak; this leads to Coulomb blockade and enables the extraction of electron addition energy of the nanocrystals. The addition energy displays superconducting parity effect, a direct consequence of Cooper pairing. Due to the electrons forming Cooper pairs when an electron is added to the nanocrystal superconductor, the additional energy is different whether there is an even or odd number of electrons. Studying this parity effect as a function of nanocrystal volume, we find the suppression of Cooper pairing when the mean electronic level spacing overcomes the superconducting gap energy, thus demonstrating unambiguously the validity of the Anderson criterion.
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Dates et versions

hal-04039477 , version 1 (21-03-2023)

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Paternité - Pas d'utilisation commerciale - Pas de modification

Identifiants

  • HAL Id : hal-04039477 , version 1

Citer

Stéphane Pons, Sergio Vlaic, Tianzhen Zhang, Alexandre Assouline, Alexandre Zimmers, et al.. How small a superconductor can be?. International Workshop Theory Meets Experiment in Low-Dimensional Structures with Correlated Electrons Prague, July 1–4, 2019, Jul 2019, Prague, Czech Republic. ⟨hal-04039477⟩
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