Search results for "fluctuation"

showing 10 items of 357 documents

Correlation between optical properties and barrier composition in InxGa1−xP/GaAs quantum wells

1998

9 páginas, 11 figuras.

III-V semiconductorsPhotoluminescenceMaterials scienceBand gapExcitonAlloyGeneral Physics and Astronomyengineering.materialGallium arsenideSpectral line broadeningchemistry.chemical_compoundCondensed Matter::Materials ScienceGallium arsenideIndium compounds:FÍSICA [UNESCO]Optical constantsInterface structureFluctuationsSemiconductor quantum wellsPhotoluminescenceQuantum wellCondensed matter physicsCondensed Matter::OtherGallium compoundsUNESCO::FÍSICAHeterojunctionInterface statesCondensed Matter::Mesoscopic Systems and Quantum Hall EffectStoichiometryEnergy gapchemistryIndium compounds ; Gallium compounds ; III-V semiconductors ; Gallium arsenide ; Semiconductor quantum wells ; Interface structure ; Photoluminescence ; Excitons ; Interface states ; Fluctuations ; Stoichiometry ; Spectral line broadening ; Energy gap ; Optical constantsengineeringExcitonsMolecular beam epitaxy
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Long-Term Consequences of Water Pumping on the Ecosystem Functioning of Lake Sekšu, Latvia

2020

Cultural eutrophication, the process by which pollution due to human activity speeds up natural eutrophication, is a widespread and consequential issue. Here, we present the 85-year history of a small, initially Lobelia&ndash

INDICATORS0106 biological scienceslcsh:Hydraulic engineeringwater level fluctuationGeography Planning and DevelopmentDIAGENESISNorthern EuropeLEVEL FLUCTUATIONS01 natural sciencesBiochemistrylcsh:Water supply for domestic and industrial purposes:Geofag: 450 [VDP]CULTURAL EUTROPHICATION:Geosciences: 450 [VDP]Water Science and Technologybiologymulti-proxy approachPlanktonCladoceraSTATE6. Clean waterORGANIC-MATTEReutrophicationOceanographyCladocera1181 Ecology evolutionary biologyHypolimnionSEDIMENTS010506 paleontologyINDEXESAquatic ScienceChironomidaeHYPOLIMNETIC OXYGENdiatomslcsh:TC1-978Ecosystem14. Life underwater1172 Environmental sciences0105 earth and related environmental scienceslcsh:TD201-500010604 marine biology & hydrobiologyfungiSediment15. Life on landbiology.organism_classificationWater levelDiatom13. Climate actionEnvironmental scienceEutrophicationSOUTHERN FINLANDWater
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Probing the creatable character of perturbed Friedmann-Robertson-Walker universes

2008

We discuss whether some perturbed Friedmann-Robertson-Walker (FRW) universes could be creatable, i. e., could have vanishing energy, linear momentum and angular momentum, as it could be expectable if the Universe arose as a quantum fluctuation. On account of previous results, the background is assumed to be either closed (with very small curvature) or flat. In the first case, fully arbitrary linear perturbations are considered; whereas in the flat case, it is assumed the existence of: (i) inflationary scalar perturbations, that is to say, Gaussian adiabatic scalar perturbations having an spectrum close to the Harrison-Zel'dovich one, and (ii) arbitrary tensor perturbations. We conclude that…

Inflation (cosmology)PhysicsNuclear and High Energy PhysicsAngular momentumGravitational wavemedia_common.quotation_subjectAstrophysics (astro-ph)Scalar (mathematics)FOS: Physical sciencesGeneral Relativity and Quantum Cosmology (gr-qc)Astrophysics::Cosmology and Extragalactic AstrophysicsAstrophysicsGeneral Relativity and Quantum CosmologyUniverseGeneral Relativity and Quantum Cosmologysymbols.namesakeClassical mechanicsFriedmann–Lemaître–Robertson–Walker metricsymbolsTensorQuantum fluctuationmedia_commonPhysical Review D
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Le mouvement des idées monétaires dans l'Europe moderne

2014

Ce chapitre vise à fournir une vue de l'évolution des idées monétaires dans l'Europe moderne. Il s'alimente notamment des textes des auteurs du présent livre pour en dégager quelques leçons. Dans un premier temps, il discutera du sens du substantif " mercantilisme " tel qu'il a été construit depuis le milieu du dix-huitième siècle : examiner les fondements historiques de cette notion permettra d'en montrer les impasses. Il présentera, dans un second temps, une catégorisation des auteurs construite à partir de leur rapport au pouvoir.

JEL: N - Economic History/N.N1 - Macroeconomics and Monetary Economics • Industrial Structure • Growth • Fluctuations/N.N1.N13 - Europe: Pre-1913History of economic thought. Mercantilism. Power. Early modern EuropeJEL: B - History of Economic Thought Methodology and Heterodox Approaches/B.B1 - History of Economic Thought through 1925/B.B1.B11 - Preclassical (Ancient Medieval Mercantilist Physiocratic)Histoire de la pensée économique. Mercantilisme. Pouvoir. Europe moderne.JEL : N - Economic History/N.N1 - Macroeconomics and Monetary Economics • Industrial Structure • Growth • Fluctuations/N.N1.N13 - Europe: Pre-1913[ SHS.ECO ] Humanities and Social Sciences/Economies and financesJEL : B - History of Economic Thought Methodology and Heterodox Approaches/B.B1 - History of Economic Thought through 1925/B.B1.B11 - Preclassical (Ancient Medieval Mercantilist Physiocratic)[SHS.ECO]Humanities and Social Sciences/Economics and Finance[SHS.ECO] Humanities and Social Sciences/Economics and Finance
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Introduction. Les pensées monétaires dans l'Europe moderne : contexte et intentions

2014

Ce texte introduit le livre et présente ses objectifs et sa structure. Ce livre traite du déploiement des idées monétaires dans le monde européen de l'époque moderne, depuis les écrits de Nicolas Copernic (1517) jusqu'à la veille de la publication de l'ouvrage économique majeur écrit par Adam Smith (1776) . Il met l'accent sur le contexte historique dans le cadre duquel ces idées monétaires ont vu le jour. Il montre la grande variété des contextes et des idées bien au-delà des espaces, des auteurs et des thèmes généralement étudiés, en intégrant des territoires peu étudiés par les économistes, en mettant au jour des approches et des auteurs oubliés, en tentant, enfin, de restituer la riches…

JEL: N - Economic History/N.N1 - Macroeconomics and Monetary Economics • Industrial Structure • Growth • Fluctuations/N.N1.N13 - Europe: Pre-1913JEL: B - History of Economic Thought Methodology and Heterodox Approaches/B.B1 - History of Economic Thought through 1925/B.B1.B11 - Preclassical (Ancient Medieval Mercantilist Physiocratic)JEL : N - Economic History/N.N1 - Macroeconomics and Monetary Economics • Industrial Structure • Growth • Fluctuations/N.N1.N13 - Europe: Pre-1913[ SHS.ECO ] Humanities and Social Sciences/Economies and financesJEL : B - History of Economic Thought Methodology and Heterodox Approaches/B.B1 - History of Economic Thought through 1925/B.B1.B11 - Preclassical (Ancient Medieval Mercantilist Physiocratic)[SHS.ECO] Humanities and Social Sciences/Economics and Finance[SHS.ECO]Humanities and Social Sciences/Economics and FinanceHistoire de la pensée économique. Europe moderne.History of economic thought. Early modern Europe.
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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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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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Nonlinear relaxation phenomena in metastable condensed matter systems

2016

Nonlinear relaxation phenomena in three different systems of condensed matter are investigated. (i) First, the phase dynamics in Josephson junctions is analyzed. Specifically, a superconductor-graphene-superconductor (SGS) system exhibits quantum metastable states, and the average escape time from these metastable states in the presence of Gaussian and correlated fluctuations is calculated, accounting for variations in the the noise source intensity and the bias frequency. Moreover, the transient dynamics of a long-overlap Josephson junction (JJ) subject to thermal fluctuations and non-Gaussian noise sources is investigated. Noise induced phenomena are observed, such as the noise enhanced s…

Josephson effectQuantum noise enhanced stabilityGeneral Physics and AstronomyThermal fluctuationslcsh:AstrophysicsDouble-well potential01 natural sciences7. Clean energySettore FIS/03 - Fisica Della Materia010305 fluids & plasmasOpen quantum systemsMetastabilityMetastabilityJosephson junctionlcsh:QB460-4660103 physical sciencesSpin polarized transport in semiconductorsddc:530lcsh:Science010306 general physicsSpin (physics)Quantum fluctuationNoise enhanced stabilityPhysicsmetastability; nonequilibrium statistical mechanics and nonlinear relaxation time; noise enhanced stability; Josephson junction; spin polarized transport in semiconductors; open quantum systems; quantum noise enhanced stabilityCondensed matter physicsNonequilibrium statistical mechanics and nonlinear relaxation timeJosephson junction; Metastability; Noise enhanced stability; Nonequilibrium statistical mechanics and nonlinear relaxation time; Open quantum systems; Quantum noise enhanced stability; Spin polarized transport in semiconductorsDissipationlcsh:QC1-999Open quantum systemlcsh:Qlcsh:PhysicsNoise (radio)
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RELAXATION PHENOMENA IN CLASSICAL AND QUANTUM SYSTEMS

2012

Relaxation phenomena in three different 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 nonmonotonicbehavior 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 effect of a Lévy 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 resonan…

Josephson effectsquantum noisefluctuation phenomenarandom processeStochastic analysis methodBrownian motiontunneling phenomenaSettore FIS/03 - Fisica Della Materia
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