Defect motions and smearing of Shapiro steps in Josephson-junction ladders under magnetic frustration

Journal Article · Fri Mar 31 23:00:00 EST 1995 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.51.8462· OSTI ID:6401460

Kim, B J; Kim, S; Lee, S J ^[1]

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1. Center for Theoretical Physics and Department of Physics, Seoul National University, Seoul 151-742 (Korea, Republic of)

We present simulation results on the dynamics of 1D Josephson ladder arrays at zero temperature in the presence of uniform magnetic fields when dc plus ac currents are applied. For a frustration [ital f]=[ital p]/[ital q], the dynamics of the array can be described by the reduced equations for only [ital q] variables, if the initial configuration is assumed to be invariant under the [ital q]-lattice translation. When dc plus ac currents are injected, fractional Shapiro steps are found at time-averaged voltage [l angle][ital V][r angle]=([ital n]/[ital q])([h bar][omega]/2[ital e]) with [ital n] an integer and [omega] the external driving frequency. If the ladder array is wound into an [ital annular] geometry, we can have defects in the vortex configuration depending on the initial random-phase configuration which cannot evolve into [ital q]-periodic states, and these defects are shown to smear the Shapiro steps. The dynamic resistance on the smeared Shapiro step is proportional to the number density of the defects.

• OSTI ID: 6401460
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 51:13; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

665410* -- Superconductivity-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
DYNAMICS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
FLUCTUATIONS
JOSEPHSON EFFECT
JOSEPHSON JUNCTIONS
JUNCTIONS
LADDER APPROXIMATION
MAGNETIC FIELDS
MAGNETIC FLUX
MECHANICS
ORDER-DISORDER TRANSFORMATIONS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
SUPERCONDUCTING JUNCTIONS
SUPERCONDUCTORS
TEMPERATURE ZERO K
TYPE-II SUPERCONDUCTORS
VARIATIONS