Abstract
Evidence is reported that topological effects in graph-shaped arrays of superconducting islands can condition superconducting energy gap and transition temperature. The carriers giving rise to the new phase are couples of electrons (Cooper pairs) which, in the superconducting state, behave as predicted for bosons in our structures. The presented results have been obtained both on star and double comb-shaped arrays and the coupling between the islands is provided by Josephson junctions whose potential can be tuned by external magnetic field or temperature. Our peculiar technique for probing distribution on the islands is such that the hopping of bosons between the different islands occurs because their thermal energy is of the same order of the Josephson coupling energy between the islands. Both for star and double comb graph topologies the results are in qualitative and quantitative agreement with theoretical predictions.
Funder
Istituto Nazionale di Fisica Nucleare
Subject
General Physics and Astronomy
Reference33 articles.
1. Topology, Geometry and Quantum Interference in Condensed Matter Physics,2017
2. Topological states of condensed matter
3. Ordering, metastability and phase transitions in two-dimensional systems
4. Superfluids: Macroscopic Theory of Superconductivity;London,1961
5. Superfluids: Macroscopic Theory of Superfluid Helium;London,1964
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