Related papers: Pinning effects on hot-electron vortex flow instab…
Larkin and Ovchinnikov established that the viscous flow of magnetic flux quanta in current-biased superconductor films placed in a perpendicular magnetic field can lose stability due to a decrease in the vortex viscosity coefficient $\eta$…
We study effects of pinning on the dynamics of a vortex lattice in a type II superconductor in the strong-pinning situation and determine the force--velocity (or current--voltage) characteristic combining analytical and numerical methods.…
An one-dimensional model of magnetic flux penetration into thin strip-like superconductive film is subject to numerical analysis which combines explicit account for specific oblate geometry of magnetic field lines around the film and a…
We calculate the distribution of the current density $j$ in superconducting films along the direction of an external field applied perpendicular to the film plane. Our analysis reveals that in the presence of bulk pinning $j$ is…
Infrared spectroscopy has been used to investigate the temperature dependence and c-axis magnetic field dependence of the Josephson plasma resonance in optimally doped Tl2Ba2CaCu2O8 thin films, and underdoped YBa2Cu3O6.5 ortho - II single…
We report the effect of high pressure on the superconducting, vortex pinning, and structural properties of a polycrystalline non-centrosymmetric superconductor Re6Hf. The superconducting transition temperature, Tc, reveals a modest decrease…
We investigate electron transport and phase-breaking processes in thin titanium nitride (TiN) films of epitaxial quality. Previous studies show that a minute surface magnetic disorder significantly reduces the critical temperature…
Hybrid magnetic arrays embedded in superconducting films are ideal systems to study the competition between different physical (such as the coherence length) and structural length scales such as available in artificially produced…
Understanding the effect of pinning on the vortex dynamics in superconductors is a key factor towards controlling critical current values. Large-scale simulations of vortex dynamics can provide a rational approach to achieve this goal.…
The parallel magnetic field tuned two-dimensional superconductor-insulator transition has been investigated in ultrathin films of amorphous Bi. The resistance is found to be independent of temperature on both sides of the transition below…
The electromagnetic properties of type-II superconductors depend on vortices -- magnetic flux lines whose motion introduces dissipation that can be mitigated by pinning from material defects. The material disorder landscape is tuned by the…
Nb films containing extended arrays of holes with 45-nm diameter and 100-nm spacing have been fabricated using anodized aluminum oxide (AAO) as substrate. Pronounced matching effects in the magnetization and Little-Parks oscillations of the…
Extensive work has shown that irradiation with 0.8 GeV protons can produce randomly oriented columnar defects (CD's) in a large number of HTS materials, specifically those cuprates containing Hg, Tl, Pb, Bi, and similar heavy elements.…
New results of the investigations critical current problems in the high temperature oxide superconductors are presented, basing on an analysis of the flux pinning on nano-sized centers. New model of the interaction pancake vortices with the…
We have combined high resolution magneto-optical imaging with an ultra-fast heating/cooling technique to measure the movement of individual vortices in a superconducting film. The motion took place while the film was heated close to $T_c$,…
Measurements of the Hall effect and the resistivity in twinned YBa2Cu3O7-delta thin films in magnetic fields B oriented parallel to the crystallographic c-axis and to the twin boundaries reveal a double sign reversal of the Hall coefficient…
The vortex dynamics in superconducting films deposited on top of a five-fold Penrose array of magnetic dots is studied by means of transport measurements. We show that in the low pinning regime (demagnetized dots) a few periodic and…
We identify a phase transition in the vortex system of a high-temperature superconductor with nano-columnar stacks of precipitates as strong vortex pinning centers. Above a particular, temperature-dependent field $B_X(T)$ the vortex…
We have studied the influence of a square array of pinning centers on the dynamics of vortex avalanches in Pb thin films by means of ac- and dc- magnetization measurements. Close to the superconducting transition Tc the commensurability…
We report measurements of the electric field vs. current density [E(J] characteristics in the mixed state of amorphous Nb0.7Ge0.3 microbridges. Close to the transition temperature Tc the Larkin-Ovchinnikov theory of nonlinear flux flow and…