Shell structure and strengthening of superconducting pair correlation in nanoclusters
Abstract
The existence of shell structure and the accompanying high degeneracy of electronic levels leads to the possibility of strong superconducting pairing in metallic nanoclusters with Ñ102-103 delocalized electrons. The most favorable cases correspond to (a) “magic” clusters with strongly degenerate highest occupied and lowest unoccupied shells and a relatively small energy spacing between them as well as to (b) clusters with slightly incomplete shells and small Jahn-Teller splitting. It is shown that realistic sets of parameters lead to very high values of Tc as well as to a strong alteration of the energy spectrum. The impact of fluctuations is analyzed. Spectroscopic experiments aimed at detecting the presence of pair correlations are proposed. The pairing should also manifest itself via odd-even effects in cluster spectra, similar to the case in nuclei.
- Publication:
-
Physical Review B
- Pub Date:
- July 2006
- DOI:
- 10.1103/PhysRevB.74.024514
- arXiv:
- arXiv:cond-mat/0603733
- Bibcode:
- 2006PhRvB..74b4514K
- Keywords:
-
- 74.78.Na;
- 74.70.-b;
- 36.40.-c;
- Mesoscopic and nanoscale systems;
- Superconducting materials;
- Atomic and molecular clusters;
- Condensed Matter - Superconductivity;
- Condensed Matter - Other;
- Physics - Atomic and Molecular Clusters
- E-Print:
- Phys. Rev. B 74, 024514 (2006)