1,721,056 research outputs found
Chaotic dynamics in the map model of fluxon propagation in long Josephson junctions
No full textChaotic dynamics in a model of a long Josephson junction (LJJ) is studied via standard techniques of non-linear maps. A characterization of chaos in such objects in terms of Lyapunov exponents and Poincaré sections is given. Finally the occurrence of chaos in map dynamics is compared with preliminary results of full numerical integration of the perturbed sine-Gordon equation (PSGE)
On technolgy competition: a formal analysis of the sailing-ship effect
No full textOne of the key features of our economies consists of the coexistence of different technologies supplying similar products and services. We often observe that an old technology is improved when a new one appears; behind this process of improvement often lies an intentional research activity. There thus begins a competition between the two technologies whose performances are improved via R&D. We focus our attention on this competition process and supply a formal model, based on the optimization of R&D expenditure of both technologies, which can describe the dynamics of the delayed overtaking of the new technology over the old on
Chaotic motion of solitons in PDE model of fluxon propagation in Long Josephson Junctions
No full textVortex Interaction Energy in Planar Josephson Junction Arrays at High Density
No full textWe study the vortex-vortex and vortex-antivortex interaction in arrays of Josephson junction particularly addressing the effect of mutual induction in the intermediate screening ranges (betaa = 0.5). The modifications of the barrier energy for the displacement of a vortex in presence of a second vortex (antivortex), or more vortices (antivortices), are derived in an "adiabatic" approach. To this end, we have developed a fast explicit algorithm, which permits to retrieve the phases and the magnetization of the array in a reasonable time and with little memory occupation for relatively large arrays [e.g. o(100 times 100)]. This new model is able to catch the essential characters of the more complex "fully mutual coupling" model. We provide also some indications on the relation between energy barriers and the observation of vortex quantum tunneling phenomena in Josephson arrays and related systems as high-TC films
Efficiency of diode effect in asymmetric inline long Josephson junctions
No full textAn effective superconducting diode-that is an element whose critical current depends upon the polarity-is achieved with a special configuration of a long Josephson junction and a control line. The proposed geometry is simple, based on the well-established asymmetric inline long Josephson junction, and can be realized using traditional superconductors without the need of magnetic materials. The performance of the diode, as measured by the efficiency, only depends on the normalized length and the control current intensity. At the optimal working point, the efficiency reaches about 76% and could be further improved at the expenses of the circuit simplicity. Finally, when a sinusoidal current is applied to the device, calculations with realistic fabrication parameters show the rectification of a sinusoidal current with a frequency in the MHz region
Suppression of chaos in the perturbed sine-Gordon system by weak periodic signals
No full textSuppression of temporal phase locked chaos in the perturbed sine-Gordon system is demonstrated by numerical simulations of the full equation in the presence of two harmonic signals. Results have been compared with a simple perturbative approach for the soliton dynamics
SUPPRESSION OF CHAOS IN THE PERTURBED SINE-GORDON SYSTEM BY WEAK PERIODIC SIGNALS
No full textSuppression of temporal phase locked chaos in the perturbed sine-Gordon system is demonstrated by numerical simulations of the full equation in the presence of two harmonic signals. Results have been compared with a simple perturbative approach for the soliton dynamics
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