English
Related papers

Related papers: The decrease of the critical current of coated con…

200 papers

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…

Superconductivity · Physics 2009-01-14 F. Hengstberger , M. Eisterer , M. Zehetmayer , H. W. Weber

Superconducting critical currents $j_{c} > 10^{5}$ A/cm$^{2}$ at temperatures $T \sim 50$ K and magnetic fields $B \sim 6$ T are reported for the YBa$_{2}$Cu$_{3-x}$Mo$_{x}$O$_{7+d}$ compound with $x = 0.02$. Clear evidence for the…

Superconductivity · Physics 2009-11-11 K. Rogacki , B. Dabrowski , O. Chmaissem

The microscopic theory of Josephson effect in point contacts between two-band superconductors is developed. The general expression for the Josephson current, which is valid for arbitrary temperatures, is obtained. We considered the dirty…

Superconductivity · Physics 2009-10-09 A. N. Omelyanchouk , Y. S. Yerin

Striation of HTS coated conductors (CCs) as a way to reduce their magnetization AC losses has been the subject of intense research in the past years by several groups. While the principle of this approach is well understood, its practical…

Employing mutual-inductance measurements we study the magnetic field dependence of complex AC susceptibility of artificially prepared highly ordered (periodic) two-dimensional Josephson junction arrays of unshunted Nb-AlO_x-Nb junctions.…

Superconductivity · Physics 2015-06-25 F. M. Araujo-Moreira , W. Maluf , S. Sergeenkov

We discuss predictions of five proposed theories for the critical state of type-II superconductors accounting for both flux cutting and flux transport (depinning). The theories predict different behaviours for the ratio $E_y/E_z$ of the…

Superconductivity · Physics 2011-05-09 John R. Clem , Marcus Weigand , J. H. Durrell , A. M. Campbell

Josephson junctions were photogenerated in underdoped thin films of the YBa$_2$Cu$_3$O$_{6+x}$ family using a near-field scanning optical microscope. The observation of the Josephson effect for separations as large as 100 nm between two…

Superconductivity · Physics 2009-10-31 R. S. Decca , H. D. Drew , E. Osquiguil , B. Maiorov , J. Guimpel

We carry out an extensive experimental and theoretical study of the Josephson effect in S-N-S junctions made of a diffusive normal metal (N) embedded between two superconducting electrodes (S). Our experiments are performed on Nb-Cu-Nb…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 P. Dubos , H. Courtois , B. Pannetier , F. K. Wilhelm , A. D. Zaikin , G. Schon

Transport measurements carried out on twinned ybco films are compared to the predictions of a previously proposed model suggesting that the vortices move along the films twin boundaries that behave as rows of Josephson weak links…

Superconductivity · Physics 2007-12-24 P. Bernstein , J. F. Hamet , Y. Thimont

In type-II superconductors, in the regime of very high applied current density, an abrupt transition is experimentally observed from the mixed state to a highly dissipative regime, probably the normal state. This provokes a high voltage…

Superconductivity · Physics 2009-09-29 Jose Viña

The AC loss in ReBCO coated conductors is large in situations when the conductors are subjected to a considerable magnetic field, like in rotating machines, transformers and high-field magnets. Roebel cables can reduce the AC loss in these…

Superconductivity · Physics 2015-05-30 Enric Pardo , Francesco Grilli

Recently, we showed that the self-field transport critical current, Ic(sf), of a superconducting wire can be defined in a more fundamental way than the conventional (and arbitrary) electric field criterion, Ec = 1 microV/cm. We defined…

The application of HTS coated conductors in future fusion or accelerator magnets is currently of increasing interest. High Lorentz forces and therefore high hoop stresses act on the conductors in large coils. The conductor is furthermore…

Superconductivity · Physics 2015-06-12 J. Emhofer , M. Eisterer , H. W. Weber

We have measured the current-phase relationship (CPR) of symmetric 45 degree YBaCuO grain boundary Josephson junctions. Substantial deviations of the CPR from conventional tunnel-junction behavior have been observed: (i) The critical…

Most measurements of critical current densities in YBa$_2$Cu$_3$O$_{7-\delta}$ thin films to date have been performed on films where the \textit{c}-axis is grown normal to the film surface. With such films, the analysis of the dependence of…

Superconductivity · Physics 2016-08-31 J. H. Durrell , G. Burnell , Z. H. Barber , M. G. Blamire , J. E. Evetts

We theoretically study the behavior of the critical current of a thermally-biased tunnel Josephson junction with a particular design, in which the electrodes of the junction are enclosed in two different superconducting loops pierced by…

Superconductivity · Physics 2022-07-20 Claudio Guarcello , Roberta Citro , Francesco Giazotto , Alessandro Braggio

The properties of Josephson devices are strongly affected by geometrical effects such as those associated with the magnetic field induced by the bias current. The generally adopted analysis of Owen and Scalapino [{\it Phys. Rev.}{\bf 164},…

Superconductivity · Physics 2013-04-18 Roberto Monaco , Valery P. Koshelets , Anna Mukhortova , Jesper Mygin

Josephson superconducting qubits and parametric amplifiers are prominent examples of superconducting quantum circuits that have shown rapid progress in recent years. With the growing complexity of such devices, the requirements for…

An improvement of the transport critical current density, Jc, of MgB2 wires was obtained after addition of 10 wt.% B4C powders, after reaction at 800 C: Jc values of 1.10^4 A/cm2 at 4.2 K and 9T were obtained for wires of 1.11 mm diameter…

Superconductivity · Physics 2009-11-11 P. Lezza , C. Senatore , R. Flukiger

We have observed the Josephson effect in junctions formed between single crystals of SrFe1.74Co0.26As2 and Ba0.23K0.77Fe2As2. I-V curves showed resistively-shunted junction characteristics, and the ac Josephson effect was observed under…