7 research outputs found
The c-axis charge traveling wave in coupled system of Josephson junctions
We demonstrate a manifestation of the charge traveling wave along the c-axis
(TW) in current voltage characteristics of coupled Josephson junctions in
high- superconductors. The branches related to the TW with different
wavelengths are found for the stacks with different number of Josephson
junctions at different values of system's parameters. Transitions between the
TW branches and the outermost branch are observed. Time dependence of the
electric charge in the superconducting layers and charge-charge correlation
functions for TW and outermost branches show different behavior with bias
current. We propose an experimental testing of the TW by microwave irradiation.Comment: Supplement : http://theor.jinr.ru/~hamdipur/lambda0.av
Manifestation of Resonance-Related Chaos in Coupled Josephson Junctions
Chaotic features of systems of coupled Josephson junctions are studied.
Manifestation of chaos in the temporal dependence of the electric charge,
related to a parametric resonance, is demonstrated through the calculation of
the maximal Lyapunov exponent, phase-charge and charge-charge Lissajous
diagrams and correlation functions. The number of junctions in the stack
strongly influences the fine structure in the current voltage characteristics
and a strong proximity effect results from the nonperiodic boundary conditions.
The observed resonance-related chaos exhibits intermittency over a range of
conditions and parameters. General features of the system are analyzed by means
of a linearized equation and the criteria for a breakpoint region with no chaos
are obtained. Such criteria could clarify recent experimental observations of
variations in the power output from intrinsic Josephson junctions in high
temperature superconductors.Comment: 13 pages, 16 figure
Charge creation and nucleation of the longitudinal plasma wave in coupled Josephson junctions
We study the phase dynamics in coupled Josephson junctions described by a system of nonlinear differential equations. Results of detailed numerical simulations of charge creation in the superconducting layers and the longitudinal plasma wave (LPW) nucleation are presented. We demonstrate the different time stages in the development of the LPW and present the results of FFT analysis at different values of bias current. The correspondence between the breakpoint position on the outermost branch of current voltage characteristics (CVC) and the growing region in time dependence of the electric charge in the superconducting layer is established. The effects of noise in the bias current and the external microwave radiation on the charge dynamics of the coupled Josephson junctions are found. These effects introduce a way to regulate the process of LPW nucleation in the stack of IJJ