相关论文: Imaging ac losses in superconducting films via sca…
Accurate determination of microscopic transport and magnetization currents is of central importance for the study of the electric properties of low dimensional materials and interfaces, of superconducting thin films and of electronic…
Although the flux density map of a bulk superconductor provides in principle sufficient information for calculating the magnitude and the direction of the supercurrent flow, the inversion of the Biot-Savart law is ill conditioned for thick…
A novel mathematical approach has been developed to complete the inversion of the Biot-Savart law in one- and two-dimensional cases from measurements of the perpendicular component of the magnetic field using the well-developed…
Large area arrays of through-thickness nanoscale pores have been milled into superconducting Nb thin films via a process utilizing anodized aluminum oxide thin film templates. These pores act as artificial flux pinning centers, increasing…
The current density and field distributions in polygonally arranged thin superconducting tapes carrying AC current are derived under the assumption of the critical state model. Starting from the generic Biot-Savart law for a general…
Scanning transmission x-ray microscopy has been used to image electric currents in superconducting films at temperatures down to 20 K. The magnetic stray field of supercurrents in a thin YBaCuO film is mapped into a soft-magnetic coating of…
The dynamics of transient current distributions in superconducting YBCO thin films were investigated during and immediately following an external field ramp, using high-speed (real-time) Magneto-Optical Imaging and calculation of dynamic…
We theoretically investigate the response of a superconducting film to line currents flowing in linear wires placed above the film, and we present analytic expressions for the magnetic-field and current distributions based on the critical…
Analytical expressions for the evaluation of AC losses in a superconductor-metal composite strip in a nonuniform AC magnetic field having the form of a standing wave are derived. The considered configuration models superconducting tapes,…
It is shown that integration of a thin film superconducting strip with current-carrying control wires enables one to engineer a profile of supercurrent density $J(x)$ with no current crowding at the edges of a strip wider than the magnetic…
We have studied the local critical current density, jc, in the superconductor thin film of bilayer structures consisting of YBa2Cu3O7 and the ferromagnets La2/3Ca1/3MnO3 and SrRuO3, respectively, by means of quantitative magneto-optics. A…
The case of ac transport at in-phase alternating applied magnetic fields for a superconducting rectangular strip with finite thickness has been investigated. The applied magnetic field is considered perpendicular to the current flow. We…
Quantized magnetic vortices driven by electric current determine key electromagnetic properties of superconductors. While the dynamic behavior of slow vortices has been thoroughly investigated, the physics of ultrafast vortices under strong…
Spatially resolved characterization of the critical current density Jc in superconductors under high magnetic fields is crucial for both fundamental understanding and practical applications. However, conventional techniques primarily…
The distribution of ac magnetic fields in a thin superconducting strip is calculated when an ac current is applied to the sample. The edge barrier of the strip to flux penetration and exit is taken into account. The obtained formulas…
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…
Superconducting YBaCuO thin films were equipped with a special arrangement of antidots (holes) of 1 micron radius in order to guide the stream of magnetic flux moving in (or out of) the sample. The flux distribution and its dynamics were…
Numerical simulations of the current and field distribution in thin superconducting films are carried out for a given material law Jc(B) and as a function of the applied field H, taking the sample's self-field into account. The dependence…
The current distribution and the AC loss in a composite superconducting tape containing a layer from magnetic material is calculated and compared with experiments, showing a very good agreement. The situations of an alternating uniform…
A study of magnetic flux penetration in a superconducting film patterned with arrays of micron sized antidots (microholes) is reported. Magneto-optical imaging (MOI) of a YBCO film shaped as a long strip with perpendicular antidot arrays…