120 research outputs found
Experimental observation of the longitudinal plasma excitation in intrinsic Josephson junctions
We have investigated the current-voltage characteristics (IVCs) of intrinsic
Josephson junctions (IJJs). Recently, it is predicted that the longitudinal
plasma wave can be excited by the parametric resonance in IJJs. Such an
excitation induces a singularity called as breakpoint region around switch back
region in the IVC. We have succeeded in the observation of the breakpoint
region in the IVC of the mesa with 5 IJJs at 4.2 K. Furthermore, it is found
that the temperature dependence of the breakpoint current is in agreement with
the theoretical prediction. This suggests that the wave number of the excited
plasma wave varies with temperature.Comment: 7 pages, 7 figures. Dubna-Nano2008, Accepted for JPCS
Effect of microwave irradiation on parametric resonance in intrinsic Josephson junctions
The effect of microwave irradiation on the phase dynamics of intrinsic
Josephson junctions in high temperature superconductors is investigated. We
demonstrate the influence of microwave's amplitude variation on the
current-voltage characteristics and on the time dependence (temporal
oscillations) of the electric charge in the superconducting layers. A
remarkable changing of the longitudinal plasma wavelength at parametric
resonance is shown. We demonstrate an effect of the microwave radiation on the
width of the parametric resonance region.Comment: 6 pages, Manuscript for PLASMA-2012 conferenc
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
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
Shapiro and parametric resonances in coupled Josephson junctions
The effect of microwave irradiation on the phase dynamics of intrinsic
Josephson junctions in high temperature superconductors is investigated. We
compare the current-voltage characteristics for a stack of coupled Josephson
junctions under external irradiation calculated in the framework of CCJJ and
CCJJ+DC models.Comment: 4 pages, Manuscript for Dubna-Nano 2012, submitted for Journal of
Physics:Conference Serie
Structure of the breakpoint region in CVC of the intrinsic Josephson junctions
A fine structure of the breakpoint region in the current-voltage
characteristics of the coupled intrinsic Josephson junctions in the layered
superconductors is found. We establish a correspondence between the features in
the current-voltage characteristics and the character of the charge
oscillations in superconducting layers in the stack and explain the origin of
the breakpoint region structure.Comment: 5 pages, 5 figures. Accepted for Phys.Rev.
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