Related papers: Flux Distribution in Superconducting Films with Ho…
We study the superconductor-insulator transition in nanohole ultrathin films in a transverse magnetic field by numerical simulation of a Josephson-junction array model. Geometrical disorder due to the random location of nanoholes in the…
The sub-microsecond dynamics of thermomagnetic avalanches in superconducting films with non-conducting holes (antidots) is considered. When such an avalanche reaches a hole, it is quickly filled with magnetic flux, and often its rim becomes…
Magnetic flux distribution across a high-temperature superconductor strip is measured using magneto-optical imaging at 15 K. Both the current-carrying state and the remanent state after transport current are studied up to the currents 0.97…
The variety of morphologies in flux patterns created by thermomagnetic dendritic avalanches in type-II superconducting films is investigated using numerical simulations. The avalanches are triggered by introducing a hot spot at the edge of…
The damping of the oscillations of a small permanent magnet (spherical shape, radius 0.1 mm) levitating between two parallel epitaxial YBCO films is measured as a function of oscillation amplitude and temperature. At small amplitudes the…
The magnetic flux penetration into the half-space superconductor sample is studied in the flux flow regime in parallel geometry assuming that an external magnetic field increasing with time in accordance with the power law. Assuming that…
Magneto-optical imaging was used to study a zero-field-cooled MgB2 film at 9.6K where in a slowly increasing field the flux penetrates by abrupt formation of large dendritic structures. Simultaneously, a gradual flux penetration takes…
When a current is applied to a type-I superconducting strip containing a narrow channel across its width, magnetic flux spots nucleate at the edge and are then driven along the channel by the current. These flux "drops" are reminiscent of…
The accurate understanding of flux dynamics is essential for the design and operation of superconducting circuits. The time evolution of flux-density distribution in an NbN strip by the transport current was observed using high-speed…
The distributions of electrical current and magnetic field in a thin-film superconductor ring is calculated by solving the London equation. The maximum amount of flux trapped by the hole, the fluxoid saturation number, is obtained by…
We have patterned a hexagonal array of nano-scale holes into a series of ultrathin, superconducting Bi/Sb films with transition temperatures 2.65 K $<T_{co} < $5 K. These regular perforations give the films a phase-sensitive periodic…
In this paper we develop a theory of mesoscopic fluctuations in disordered thin superconducting films in a parallel magnetic field. At zero temperature and sufficiently strong magnetic field the system undergoes a phase transition into a…
We have performed flux noise and AC-susceptibility measurements on two 400 nm thick MgB$_2$ films. Both measurement techniques give information about the vortex dynamics in the sample, and hence the superconducting transition, and can be…
It is shown how the static and dynamic electromagnetic properties can be calculated for thin flat superconducting films of any shape and size, also multiply connected as used for SQUIDs, and for any value of the effective magnetic London…
We studied the tunneling density of states in YBCO films under strong currents flowing along node directions. The currents were induced by fields of up to 32.4T parallel to the film surface and perpendicular to the $CuO_{2}$ planes. We…
We created local pinning modulations in YBCO films by means of confined high energy heavy ion irradiation. The high energy of the ions allows us to introduce nanometric size defects with a well defined anisotropy. The dose was chosen in…
Magnetic flux front and induction contours in superconducting YBa2Cu3O7-d films with defect size s ~ l (superconducting coherence length) and s > l are studied by magneto-optical imaging. Robust self-affine spatial correlation was observed…
As first pointed out by Bardeen and Ginzburg in the early sixties, the amount of magnetic flux carried by vortices depends on their distance to the sample edge and can be smaller than one flux quantum, f0 = h/2e. In bulk superconductors,…
We report measurements of the magnetic penetration depth in YBCO films at various oxygen concentrations. At optimal doping, critical fluctuation effects are absent, and the penetration depth from 4 K to 0.99 Tc is well described by d-wave,…
The trapped magnetic field is examined in bulk high-temperature superconductors that are artificially drilled along their c-axis. The influence of the hole pattern on the magnetization is studied and compared by means of numerical models…