In:
Japanese Journal of Applied Physics, IOP Publishing, Vol. 33, No. 6R ( 1994-06-01), p. 3435-
Abstract:
We report the fabrication and characterization of thin-film Nb–(Nb nanoconstrictions)–NbN short weak links prepared by applying an electric field to an insulating Nb/MgO/NbN edge sandwich with an area of 0.2 µm 2 . The growth of Nb nanoconstrictions in the MgO ( ∼7 nm thick) insulator layer connecting two superconducting banks is assisted by electric field in liquid helium. For an interpretation of device quasiparticle characteristics, the Blonder, Tinkham and Klapwijk (BTK) theory [Phys. Rev. B 25 (1982) 4515] is used. The current-voltage curves and excess current-normal resistance products are found to agree closely with the BTK predictions by assuming two independent (series) normal metal-superconductor contacts. The two-level fluctuation (TLF) of conductance was apparently observed in the samples with Andreev reflection probability of A ( E )≪1. For the samples with A ( E )∼1, i.e., nearly clean contacts, no apparent TLF was observed in the frequency band up to 100 kHz.
Type of Medium:
Online Resource
ISSN:
0021-4922
,
1347-4065
DOI:
10.1143/JJAP.33.3435
Language:
Unknown
Publisher:
IOP Publishing
Publication Date:
1994
detail.hit.zdb_id:
218223-3
detail.hit.zdb_id:
797294-5
detail.hit.zdb_id:
2006801-3
detail.hit.zdb_id:
797295-7
