6533b7dafe1ef96bd126e19e
RESEARCH PRODUCT
Switching times in long-overlap Josephson junctions subject to thermal fluctuations and non-Gaussian noise sources
Claudio GuarcelloDavide ValentiBernardo Spagnolosubject
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 NOISEBEHAVIORdescription
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 by the formation and propagation of solitons, with two different dynamical regimes characterizing the dynamics of the phase string. Our analysis allows to evidence the effects of different bias current densities, that is a simple spatially homogeneous distribution and a more realistic inhomogeneous distribution with high current values at the junction edges. Stochastic resonant activation, noise enhanced stability and temporary trapping phenomena are observed in the system investigated.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2014-06-17 |