Soliton excitations in Josephson tunnel junctions

Journal Article · Sat May 01 04:00:00 EDT 1982 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.25.5737· OSTI ID:5144614

Lomdahl, P S; Soerensen, O H; Christiansen, P L

A detailed numerical study of a sine-Gordon model of the Josephson tunnel junction is compared with experimental measurements on junctions with different L/lambda/sub J/ ratios. The soliton picture is found to apply well on both relatively (L/lambda/sub J/ = 6) and intermediate (L/lambda/sub J/ = 2) junctions. We find good agreement for the current-voltage characteristics, power output, and for the shape and height of the zero-field steps (ZFS). Two distinct modes of solition oscillations are observed: (i) a bunched or congealed mode giving rise to the fundamental frequency ..integral../sub 1/ on all ZFS's and (ii) a ''symmetric'' mode which on the Nth ZFS yields the frequency N..integral../sub 1/. Coexistence of two adjacent frequencies is found on the third ZFS of the longer junction (L/lambda/sub J/ = 6) in a narrow range of bias current as also found in the experiments. Small asymmetries in the experimental environment, a weak magnetic field, e.g., is introduced via the boundary conditions of our numerical model. This gives a junction response to variations in the applied bias current close to that observed experimentally.

• Research Organization: Laboratory of Applied Mathematical Physics, The Technical University of Denmark, DK-2800 Lyngby, Denmark
• OSTI ID: 5144614
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Journal Issue: 9 Vol. 25:9; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

420201* -- Engineering-- Cryogenic Equipment & Devices
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BOUNDARY CONDITIONS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
EQUATIONS
FIELD EQUATIONS
JOSEPHSON JUNCTIONS
JUNCTIONS
PHYSICAL PROPERTIES
POWER
QUASI PARTICLES
SINE-GORDON EQUATION
SOLITONS
SUPERCONDUCTING JUNCTIONS