1,860 research outputs found
Phase synchronization in an array of driven Josephson junctions
We consider an array of N Josephson junctions connected in parallel and
explore the condition for chaotic synchronization. It is found that the outer
junctions can be synchronized while they remain uncorrelated to the inner ones
when an external biasing is applied. The stability of the solution is found out
for the outer junctions in the synchronization manifold. Symmetry
considerations lead to a situation wherein the inner junctions can synchronize
for certain values of parameter. In the presence of a phase difference between
the applied fields, all the junctions exhibit phase synchronization. It is also
found that chaotic motion changes to periodic in the presence of phase
differences.Comment: 13 pages, 6 figures, accepted for publication in "CHAOS
Rapid convergence of time-averaged frequency in phase synchronized systems
Numerical and experimental evidence is presented to show that many phase
synchronized systems of non-identical chaotic oscillators, where the chaotic
state is reached through a period-doubling cascade, show rapid convergence of
the time-averaged frequency. The speed of convergence toward the natural
frequency scales as the inverse of the measurement period. The results also
suggest an explanation for why such chaotic oscillators can be phase
synchronized.Comment: 6 pages, 9 figure
Enhanced synchronization in an array of spin torque nano oscillators in the presence of oscillating external magnetic field
We demonstrate that the synchronization of an array of electrically coupled
spin torque nano-oscillators (STNO) modelled by
Landau-Lifshitz-Gilbert-Slonczewski (LLGS) equation can be enhanced appreciably
in the presence of a common external microwave magnetic field. The applied
microwave magnetic field stabilizes and enhances the regions of synchronization
in the parameter space of our analysis, where the oscillators are exhibiting
synchronized oscillations thereby emitting improved microwave power. To
characterize the synchronized oscillations we have calculated the locking range
in the domain of external source frequency.Comment: Accepted for publication in Europhysics Letters (EPL
Bifurcations, Chaos, Controlling and Synchronization of Certain Nonlinear Oscillators
In this set of lectures, we review briefly some of the recent developments in
the study of the chaotic dynamics of nonlinear oscillators, particularly of
damped and driven type. By taking a representative set of examples such as the
Duffing, Bonhoeffer-van der Pol and MLC circuit oscillators, we briefly explain
the various bifurcations and chaos phenomena associated with these systems. We
use numerical and analytical as well as analogue simulation methods to study
these systems. Then we point out how controlling of chaotic motions can be
effected by algorithmic procedures requiring minimal perturbations. Finally we
briefly discuss how synchronization of identically evolving chaotic systems can
be achieved and how they can be used in secure communications.Comment: 31 pages (24 figures) LaTeX. To appear Springer Lecture Notes in
Physics Please Lakshmanan for figures (e-mail: [email protected]
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