Vortex resistivity owing to the magnetic field of the transport current in wide superconducting films

2010 ◽  
Vol 36 (12) ◽  
pp. 1042-1044 ◽  
Author(s):  
I. V. Zolochevskii
Keyword(s):  
Magnetic Field ◽  
Superconducting Films ◽  
Transport Current ◽  
The Magnetic Field

MAGNETIC FIELD DEPENDENCE OF CRITICAL CURRENTS IN SUPERCONDUCTING POLYCRYSTALS

1992 ◽  
Vol 06 (03) ◽  
pp. 161-169 ◽  
Author(s):  
K.I. KUGEL ◽  
T. YU. LISOVSKAYA ◽  
R.G. MINTS
Keyword(s):  
Magnetic Field ◽  
Magnetic Field Dependence ◽  
Asymptotic Form ◽  
Critical Currents ◽  
Transport Current ◽  
Wide Field ◽  
London Penetration Depth ◽  
Field Range ◽  
Crystallographic Axes ◽  
The Magnetic Field

We study the dependence of critical current j c on magnetic field H in superconducting polycrystals which are considered as systems of superconducting crystallites (isotropic or anisotropic) with Josephson contacts between them. Isotropy or anisotropy of contacts depends on the orientation of their crystallographic axes relatively to edges of contact planes. It is shown that for a system of randomly oriented isotropic contacts, the dependence j c (H) in a relatively wide field range has the asymptotic form j c ~( ln H)/H2. This differs drastically from j c (H) for single contacts. Anisotropy effects due to large differences in London penetration depth λ values corresponding to external magnetic field directed along different axes are analyzed in detail. It is shown that for uniaxal crystals with λ1=λ2≪λ3, this anisotropy leads to the relation [Formula: see text] for chaotic orientation of crystallites. The form of j c (H) curves for two different orientations of the magnetic field relatively to the transport current through the sample is found.

scholarly journals Критический ток в длинном джозефсоновском контакте во внешнем магнитном поле при слабом пиннинге

2022 ◽  
Vol 92 (3) ◽  
pp. 414
Author(s):  
М.А. Зеликман
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Critical Current ◽  
Critical Value ◽  
Transport Current ◽  
Entire Length ◽  
Gibbs Potential ◽  
Potential Reduction ◽  
The Magnetic Field ◽  
Josephson Contact

The analysis of possible current distributions when passing current through a periodically modulated long Josephson contact located in an external magnetic field is carried out. An approach based on the analysis of continuous configuration modification proceeding in the direction of Gibbs potential reduction is used for the calculation. The case when the pinning parameter is less than the critical value is considered. It is shown that at any value of the external magnetic field, there is a critical value of the transport current, when exceeded, the situation ceases to be stationary, as a result of which energy passes into radiation and heat, i.e. currents cease to be persistent. The value of the critical current is determined by the value of the magnetic field at which the vortices begin to fill the entire length of the contact. With an increase in the external magnetic field, the critical value of the current decreases.

On the distribution of the magnetic field of the transport current in type-II superconductor

1979 ◽  
Vol 51 (2) ◽  
pp. K117-K119 ◽  
Author(s):  
N. Alekseevsky ◽  
E. Krasnopiorov ◽  
E. Trojnar ◽  
A. J. Zaleski
Keyword(s):  
Magnetic Field ◽  
Transport Current ◽  
Type Ii ◽  
Type Ii Superconductor ◽  
The Magnetic Field

scholarly journals Levitation and Lateral Stabilization Device Based on a Second-Generation High-Temperature Superconductor

2019 ◽  
Vol 5 (4) ◽  
pp. 115-123
Author(s):  
Yuri F. Antonov
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
High Temperature Superconductor ◽  
Second Generation ◽  
Permanent Magnets ◽  
Transport Current ◽  
Critical Parameters ◽  
Technical Solution ◽  
The Magnetic Field ◽  
Superconducting Levitation

The superconducting levitation device comprises a stationary magnetic rail of permanent magnets and a cryostat on a vehicle with a second-generation high-temperature tape superconductor placed in the cryostat, folded in a stack or wound by a coil on a non-magnetic frame without electrical connection of the ends and the transport current. Cool tape high-temperature superconductor of the second generation, folded in a stack or wound on a non magnetic frame in the form of axisymmetric or track coil, without electric connections of the ends and a transport current, behaves as a massive sample of a superconductor and the Meissner Oxenfeld effect, the magnetic field created by the magnetic rail is displaced from the volume of the superconductor, causing the power of levitation and the vehicle hangs over the track structure. The high critical parameters of the second-generation high-temperature superconductor belt ensure efficient operation of the superconducting levitation device. Aim: To demonstration the technical feasibility and efficiency of creating a levitation unit based on the use of a second-generation high-temperature superconductor and permanent magnets made of rare earth metals. Methods: Calculations of the magnetic field distribution in the combination of a magnetic rail and a massive superconductor, preliminary design of the levitation unit and experimental studies on the model. Results: Experiments on a model of a superconducting levitation device confirmed the efficiency of this technical solution and its effectiveness. Conclusion: an original technical solution is proposed that allows to significantly improve the energy characteristics of the levitation node by using a second-generation high-temperature superconductor operating in a passive mode without a transport current, using the partial Meissner-Oxenfeld effect and the engagement of quantized magnetic flux strands at the pinning centers.

scholarly journals A NOVEL SUPERCONDUCTING GLASS STATE IN DISORDERED THIN FILMS IN CLOGSTON LIMIT

1999 ◽  
Vol 13 (17) ◽  
pp. 2229-2256 ◽  
Author(s):  
FEI ZHOU
Keyword(s):  
Magnetic Field ◽  
Fermi Liquid ◽  
Universality Class ◽  
Superconducting Films ◽  
Two Dimensional ◽  
Zero Temperature ◽  
Parallel Magnetic Field ◽  
Spin Polarized ◽  
The Magnetic Field ◽  
Thin Superconducting Films

A theory of mesoscopic fluctuations in disordered thin superconducting films in a parallel magnetic field is developed. At zero temperature and at a sufficiently strong magnetic field, the superconducting state undergoes a phase transition into a state characterized by superfluid densities of random signs, instead of a spin polarized disordered Fermi liquid phase. Consequently, in this regime, random supercurrents are spontaneously created in the ground state of the system, which belongs to the same universality class as the two dimensional XY spin glass. As the magnetic field increases further, mesoscopic pairing states are nucleated in an otherwise homogeneous spin polarized disordered Fermi liquid. The statistics of these pairing states is universal depending on the sheet conductance of the two-dimensional film.

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