Search results for "NOISE"

showing 10 items of 1375 documents

Transient Dynamics of Short Josephson Junctions under the influence of non-Gaussian Noise

2009

We investigate the effects of non-Gaussian white noise source on the transient dynamics of short Josephson junctions. The noise signal is simulated generating standard stable random variables with characteristic function described by Lévy index alpha and asymmetry parameter beta. We study the lifetime of the superconductive state as a function both of the frequency of the external driving bias current and the noise intensity for different values of index alpha. We compare our results with those obtained in the presence of Gaussian white noise. We find the presence of noise induced effects such as resonant activation and noise enhanced stability.

Josephson devicesStochastic processeComputational methods in statistical physics and nonlinear dynamicNoiseSettore FIS/03 - Fisica Della Materia
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Josephson-based Threshold Detector for Lévy-Distributed Current Fluctuations

2019

We propose a threshold detector for Lévy-distributed fluctuations based on a Josephson junction. The Lévy-noise current added to a linearly ramped bias current results in clear changes in the distribution of switching currents out of the zero-voltage state of the junction. We observe that the analysis of the cumulative distribution function of the switching currents supplies information on both the characteristics' shape parameter α of the Lévy statistics. Moreover, we discuss a theoretical model, which allows characteristic features of the Lévy fluctuations to be extracted from a measured distribution of switching currents. In view of these results, this system can effectively find an appl…

Josephson effect---Current (mathematics)NOISE; FLIGHTS; FLUORESCENCE; LIFETIME; MODEL; STATE; FIELDGeneral Physics and Astronomy02 engineering and technologyLIFETIMEFault (power engineering)01 natural sciencesNoise (electronics)Settore FIS/03 - Fisica Della MateriaNOISE0103 physical sciencesStatistical physicsSuperconducting electronicsFLUORESCENCEFIELD010306 general physicsPhysicsResistive touchscreenDetectorFLIGHTSState (functional analysis)Josephson junctions Lévy processes non-thermal noise current fluctuations021001 nanoscience & nanotechnologySTATEMODEL0210 nano-technology
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Noise Induced Phenomena in point Josephson junctions

2008

We present the analysis of the mean switching time and its standard deviation of short overdamped Josephson junctions, driven by a direct current and a periodic signal. The effect of noise enhanced stability is investigated. It is shown that fluctuations may both decrease and increase the switching time.

Josephson effectPhysicsCondensed matter physicsCondensed Matter - SuperconductivityApplied MathematicsDirect currentFOS: Physical sciencesNoise (electronics)Stability (probability)Standard deviationSwitching timePeriodic functionSuperconductivity (cond-mat.supr-con)Modeling and SimulationMetastabilityCondensed Matter::SuperconductivityNoise Induced PhenomenaEngineering (miscellaneous)
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INFLUENCE OF LENGTH ON THE NOISE DELAYED SWITCHING OF LONG JOSEPHSON JUNCTIONS

2008

The transient dynamics of long overlap Josephson junctions in the frame of the sine-Gordon model with a white noise source is investigated. The effect of noise delayed decay is observed for the case of overdamped sine-Gordon equation. It is shown that this noise induced effect, in the range of small noise intensities, vanishes for junctions lengths greater than several Josephson penetration length.

Josephson effectPhysicsCondensed matter physicsJosephson phaseNoise inducedCondensed Matter - SuperconductivityApplied MathematicsFOS: Physical sciencesThermal fluctuationsJosephson energyWhite noisenoise delayed switchingSuperconductivity (cond-mat.supr-con)Pi Josephson junctionCondensed Matter::SuperconductivityModeling and SimulationEngineering (miscellaneous)International Journal of Bifurcation and Chaos
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THE ROLE OF NON-GAUSSIAN SOURCES IN THE TRANSIENT DYNAMICS OF LONG JOSEPHSON JUNCTIONS

2013

We analyze the effects of different non-Gaussian noise sources on the transient dynamics of an overdamped long Josephson junction. We find nonmonotonic behavior of the mean escape time as a function of the noise intensity and frequency of the external driving signal for all the noise sources investigated.

Josephson effectPhysicsFluctuation phenomena random processes noise and Brownian motionCondensed matter physicsGaussianJosephson devicesDynamics (mechanics)General Physics and AstronomyJosephson energyComputational methods in statistical physics and nonlinear dynamicSettore FIS/03 - Fisica Della MateriaPi Josephson junctionsymbols.namesakeRandom walks and Levy flightsymbolsTransient (oscillation)
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Dephasing due to quasiparticle tunneling in fluxonium qubits: a phenomenological approach

2015

The fluxonium qubit has arisen as one of the most promising candidate devices for implementing quantum information in superconducting devices, since it is both insensitive to charge noise (like flux qubits) and insensitive to flux noise (like charge qubits). Here, we investigate the stability of the quantum information to quasiparticle tunneling through a Josephson junction. Microscopically, this dephasing is due to the dependence of the quasiparticle transmission probability on the qubit state. We argue that on a phenomenological level the dephasing mechanism can be understood as originating from heat currents, which are flowing in the device due to possible effective temperature gradients…

Josephson effectPhysicsFlux qubitCondensed Matter - Mesoscale and Nanoscale PhysicsDephasingGeneral Physics and AstronomyFOS: Physical sciencesQuantum PhysicsCondensed Matter::Mesoscopic Systems and Quantum Hall Effect530heat currentNoise (electronics)Physics and Astronomy (all)Computer Science::Emerging TechnologiesfluxoniumQubitQuantum mechanicsCondensed Matter::SuperconductivityMesoscale and Nanoscale Physics (cond-mat.mes-hall)Quasiparticleddc:530quasiparticle tunnelingQuantum informationQuantum tunnelling
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JOSEPHSON MESOJUNCTIONS AS DETECTORS OF LOW-INTENSITY QUANTIZED COHERENT FAR-INFRARED FIELDS

2000

We show that the quantum nature of a mesoscopic Josephson junction may be exploited for detecting low-intensity electromagnetic quantized fields. In particular we prove that intensity and phase of single-mode quantized coherent field may be reconstructed measuring amplitude and quantum noise of the first quantum Shapiro step occurring in the I-V characteristic of the ultrasmall Josephson junction.

Josephson effectPhysicsMesoscopic physicsCondensed matter physicsQuantum noiseStatistical and Nonlinear PhysicsCondensed Matter::Mesoscopic Systems and Quantum Hall EffectCondensed Matter Physicslaw.inventionPi Josephson junctionSQUIDFar infraredlawCondensed Matter::SuperconductivityQuantum mechanicsSuperconducting tunnel junctionQuantumInternational Journal of Modern Physics B
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2012

classical and quantum systems are investigated. First, the role of multiplicative and additive noise in a classical metastable system is analyzed. The mean lifetime of the metastable state shows a nonmonotonic behavior with a maximum as a function of both the additive and multiplicative noise intensities. In the second system, the simultaneous action of thermal and non-Gaussian noise on the dynamics of an overdamped point Josephson junction is studied. The eect of a Levy noise generated by a Cauchy‐Lorentz distribution on the mean lifetime of the superconductive metastable state, in the presence of a periodic driving, is investigated. We find resonant activation and noise enhanced stability…

Josephson effectPhysicsThermal reservoirQuantum mechanicsMetastabilityQuantum noiseTime evolutionGeneral Physics and AstronomyNoise (electronics)QuantumMultiplicative noiseActa Physica Polonica B
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Voltage drop across Josephson junctions for L\'evy noise detection

2020

We propose to characterize L\'evy-distributed stochastic fluctuations through the measurement of the average voltage drop across a current-biased Josephson junction. We show that the noise induced switching process in the Josephson washboard potential can be exploited to reveal and characterize L\'evy fluctuations, also if embedded in a thermal noisy background. The measurement of the average voltage drop as a function of the noise intensity allows to infer the value of the stability index that characterizes L\'evy-distributed fluctuations. An analytical estimate of the average velocity in the case of a L\'evy-driven escape process from a metastable state well agrees with the numerical calc…

Josephson effectPhysicsWork (thermodynamics)Settore FIS/02 - Fisica Teorica Modelli E Metodi MatematiciCondensed Matter - Mesoscale and Nanoscale PhysicsCondensed Matter - SuperconductivityFunction (mathematics)Condensed Matter::Mesoscopic Systems and Quantum Hall EffectSignalLévy noiseJosephson junctionCondensed Matter::SuperconductivityMetastabilityThermalstochastic processesStatistical physicsVoltage dropQuantum tunnelling
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Enhancement of stability in systems with metastable states

2007

The investigation of noise‐induced phenomena in far from equilibrium systems is one of the approach used to understand the behaviour of physical and biological complex systems. Metastability is a generic feature of many nonlinear systems, and the problem of the lifetime of metastable states involves fundamental aspects of nonequilibrium statistical mechanics. The enhancement of the life‐time of metastable states through the noise enhanced stability effect and the role played by the resonant activation phenomenon will be discussed in models of interdisciplinary physics: (i) Ising model (ii) Josephson junction; (iii) stochastic FitzHugh‐Nagumo model; (iv) a population dynamics model, and (v) …

Josephson effectPhysicseducation.field_of_studySettore FIS/02 - Fisica Teorica Modelli E Metodi MatematiciStochastic volatilityStochastic processPopulationComplex systemStatistical mechanicsNoise Enhanced StabilityStochastic modeling of biological and medical physicsMetastabilityQuantum mechanicsMetastabilityIsing modelStochastic dynamicStatistical physicsMetastability; Noise Enhanced Stability; Stochastic dynamics; Stochastic modeling of biological and medical physicseducation
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