Accession Number:

ADA207925

Title:

Fluxons and Order in Long Josephson Junctions

Descriptive Note:

Final rept. 15 Nov 1985-14 Nov 1988

Corporate Author:

UTAH UNIV SALT LAKE CITY DEPT OF PHYSICS

Personal Author(s):

Report Date:

1989-02-24

Pagination or Media Count:

50.0

Abstract:

Studies have been made of fluxon dynamics, instabilities, and noise in long overlap type Josephson junctions made out of Niobium Nitride and Niobium. Noise and fluctuations measurements were performed in the voltage state of the junctions biased in a magnetic field. We observed telegraph noise due to fluxon fluctuations between two energy states determined by the geometry of the junction and the external magnetic field bias. The studies covered life-times of these states, metastability, thermal and quantum mechanical tunneling, and effects of dissipation. At certain bias points of the junction we found chaotic behavior which was preceded by period-doubling bifurcation. Also negative resistance regions were observed they can be used for amplification. These observations were supported by computer modeling using a perturbed sine-Gordon equation. Fluxon motion in long Josephson junctions provides an excellent system for studies of non-linear phenomena and it has a variety of applications to superconducting electronics. Keywords Josephson junctions Superconducting electronics Fluxons Period doubling bifurcation Sine gordon equation Noise Fluctuations.

Subject Categories:

  • Electrical and Electronic Equipment
  • Solid State Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE