Search results for " Scaling laws"

showing 3 items of 3 documents

Switching times in long-overlap Josephson junctions subject to thermal fluctuations and non-Gaussian noise sources

2014

We investigate the superconducting lifetime of long current-biased Josephson junctions, in the presence of Gaussian and non-Gaussian noise sources. In particular, we analyze the dynamics of a Josephson junction as a function of the noise signal intensity, for different values of the parameters of the system and external driving currents. We find that the mean lifetime of the superconductive state is characterized by nonmonotonic behavior as a function of noise intensity, driving frequency and junction length. We observe that these nonmonotonic behaviours are connected with the dynamics of the junction phase string during the switching towards the resistive state. An important role is played…

DYNAMICSJosephson effectKRAMERS PROBLEMPhase (waves)Thermal fluctuationsFOS: Physical sciencesNoise processes and phenomenaSettore FIS/03 - Fisica Della MateriaPi Josephson junctionSuperconductivity (cond-mat.supr-con)symbols.namesakeLEVY FLIGHTSCALING LAWSCondensed Matter::SuperconductivityMesoscale and Nanoscale Physics (cond-mat.mes-hall)Stochastic analysis methodFluctuation phenomenaANOMALOUS DIFFUSIONENHANCED STABILITYSuperconductivityPhysicsRESONANT ACTIVATIONCondensed Matter - Mesoscale and Nanoscale PhysicsCondensed matter physicsNoise (signal processing)Condensed Matter - SuperconductivityBiasingJosephson deviceCondensed Matter PhysicsElectronic Optical and Magnetic MaterialsZERO-VOLTAGE STATEGaussian noisesymbolsZERO-VOLTAGE STATE; ALPHA-STABLE NOISE; RESONANT ACTIVATION; LEVY FLIGHT; ANOMALOUS DIFFUSION; ENHANCED STABILITY; KRAMERS PROBLEM; SCALING LAWS; DYNAMICS; BEHAVIORALPHA-STABLE NOISEBEHAVIOR
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Effective temperature and scaling laws of polarized quantum vortex bundles

2011

Abstract An effective non-equilibrium temperature is defined for (locally) polarized and dense turbulent superfluid vortex bundles, related to the average energy of the excitations (Kelvin waves) of vortex lines. In the quadratic approximation of the excitation energy in terms of the wave amplitude A, a previously known scaling relation between amplitude and wavelength k of Kelvin waves in polarized bundles, namely A ∝ k − 1 / 2 , follows from the homogeneity of the effective temperature. This result is analogous to that of the well-known equipartition result in equilibrium systems.

PhysicsCondensed matter physicsNon-equilibrium temperature Turbulent superfluids Vortices Scaling laws Non-equilibrium thermodynamicsQuantum vortexGeneral Physics and AstronomyNon-equilibrium thermodynamicsVortexsymbols.namesakeWavelengthAmplitudesymbolsKelvin waveScalingSettore MAT/07 - Fisica MatematicaEquipartition theorem
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Bridging scales with thermodynamics: from nano to macro

2014

We have recently developed a method to calculate thermodynamic properties of macroscopic systems by extrapolating properties of systems of molecular dimensions. Appropriate scaling laws for small systems were derived using the method for small systems thermodynamics of Hill, considering surface and nook energies in small systems of varying sizes. Given certain conditions, Hill's method provides the same systematic basis for small systems as conventional thermodynamics does for large systems. We show how the method can be used to compute thermodynamic data for the macroscopic limit from knowledge of fluctuations in the small system. The rapid and precise method offers an alternative to curre…

Surface (mathematics)PhysicsNanothermodyamicsCurrent (mathematics)Scaling lawsBasis (linear algebra)ComputationBinary numberThermodynamicsIndustrial and Manufacturing EngineeringKirkwood-Buff integralsThermodynamic factorsThermodynamic limitGeneral Materials ScienceNanothermodyamics; Scaling laws; Kirkwood-Buff integrals; Thermodynamic factors; Diffusion coefficientStatistical physicsElectrical and Electronic EngineeringDiffusion (business)MacroDiffusion coefficientAdvances in Natural Sciences: Nanoscience and Nanotechnology
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