Josephson coupling between superconducting islands on single and bilayer graphene
| Autor: | Mancarella, Francesco, Fransson, Jonas, Balatsky, Alexander |
|---|---|
| Rok vydání: | 2014 |
| Předmět: | |
| Zdroj: | Supercond. Sci. Technol. 29, 054004 (2016) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1088/0953-2048/29/5/054004 |
| Popis: | We study the Josephson coupling of superconducting (SC) islands through the surface of single-layer (SLG) and bilayer (BLG) graphene, as a function of distance between the grains, temperature, chemical potential and external (transverse) gate-voltage. For SLG, we provide a comparison with existing literature. The proximity effect is analyzed through a Matsubara Green function approach. This represents the first step in a discussion of the conditions for the onset of a granular superconductivity within the film, made possible by Josephson currents flowing between superconductors. To ensure phase coherence over the 2D sample, a random spatial distribution can be assumed for the SC islands on the SLG sheet (or intercalating the BLG sheets). The tunable gate-voltage-induced band gap of BLG affects the asymptotic decay of the Josephson coupling-distance characteristic for each pair of SC islands in the sample, which results in the end in a qualitatively strong field-dependence of the relation between Berezinskii-Kosterlitz-Thouless transition critical temperature and gate-voltage. Comment: 11 pages, 6 figures |
| Databáze: | arXiv |
| Externí odkaz: |
|