Related papers: Phase Slip Avalanches in Small Superconductors
A novel way to realize a pi Josephson junction is proposed, based on a weak link in an unconventional d-wave superconductor with appropriately chosen boundary geometry. The critical current of such a junction is calculated from a fully…
Topological defects such as dislocations and disclinations are predicted to determine the twodimensional (2-D) melting transition. In 2-D superconducting vortex lattices, macroscopic measurements evidence melting close to the transition to…
We study the critical fluctuations near the resistive transition of very thin films of high-temperature cuprate superconductors composed of a number $N$ of only a few unit cells of superconducting bilayers. For that, we solve the…
We study slip avalanches in disordered materials under an increasing external load in the framework of a fiber bundle model. Over-stressed fibers of the model do not break, instead they relax in a stick-slip event which may trigger an…
When we lower the temperature of a liquid, at some point we meet a first order phase transition to the crystal. Yet, under certain conditions it is possible to keep the system in its metastable phase and to avoid crystallization. In this…
We consider a thin superconducting film with randomly magnetized dots on top of it. The dots produce a disordered pinning potential for vortices in the film. We show that for dots with permanent and random magnetization normal or parallel…
We present low temperature tunneling density of states measurements of Pauli-limited Al films in which the Zeeman and orbital contributions to the critical field are comparable. We show that films in the thickness range of 6-7 nm exhibit a…
We study non-Gaussian out-of-equilibrium current fluctuations in a mesoscopic NSN circuit at the point of a superconducting phase transition. The setup consists of a voltage-biased thin film nanobridge superconductor (S) connected to two…
Superconducting systems may display different types of nonequilibrium states depending on the specific constraints imposed for measurement. We probe current-voltage relations of three-dimensional superconducting films by allowing finite…
The superconducting-insulator transition is simulated in disordered networks of Josephson junctions with thermally activated Arrhenius-like resistive shunt. By solving the conductance matrix of the network, the transition is reproduced in…
Superconducting fluctuations in long and narrow strips made from ultrathin NbN films, have been investigated. For large bias currents close to the critical current fluctuations led to localized, temporary transitions into the normal…
An effective field theory is derived for the normal metal-to-superconductor quantum phase transition at T=0. The critical behavior is determined exactly for all dimensions d>2. Although the critical exponents \beta and \nu do not exist, the…
A numerical method is developed to calculate the transition temperature of double or multi-layers consisting of films of super- and normal conductors. The approach is based on a dynamic interpretation of Gorkov's linear gap equation and is…
Flux distributions in thin superconducting NbN films placed in a perpendicular magnetic field have been studied using magneto-optical imaging. Below 5.5 K the flux penetrates in the form of abrupt avalanches resulting in dendritic…
DC voltage versus current measurements of superconductors in a magnetic field are widely interpreted to imply that a phase transition occurs into a state of zero resistance. We show that the widely-used scaling function approach has a…
By using multi-bands BCS theory, we have calculated the superconductivity energy gap and the critical temperature of a thin-film metallic superconductor. The thermodynamic superconducting characteristics such as critical magnetic field,…
Resistance in superconductors arises from the motion of vortices driven by flowing supercurrents or external electromagnetic fields and may be strongly affected by thermal or quantum fluctuations. The common expectation borne out in…
Classical phase transitions, like solid-liquid-gas or order-disorder spin magnetic phases, are all driven by thermal energy fluctuations by varying the temperature. On the other hand, quantum phase transitions happen at absolute zero…
We have performed flux noise and AC-susceptibility measurements on two 400 nm thick MgB$_2$ films. Both measurement techniques give information about the vortex dynamics in the sample, and hence the superconducting transition, and can be…
We investigate the effect of thermal fluctuations on the (mean-field) Abrikosov phase. The lower critical dimension of the superconducting phase is three, indicating the absence of the Abrikosov phase for dimensions d<3. Within the d=3…