1,270 research outputs found
A hierarchy of models for type-II superconductors
A hierarchy of models for type-II superconductors is presented. Through appropriate asymptotic limits we pass from the mesoscopic Ginzburg-Landau model to the London model with isolated superconducting vortices as line singularities, to vortex-density models, and finally to macroscopic critical-state models
The bifurcation diagrams for the Ginzburg-Landau system for superconductivity
In this paper, we provide the different types of bifurcation diagrams for a
superconducting cylinder placed in a magnetic field along the direction of the
axis of the cylinder. The computation is based on the numerical solutions of
the
Ginzburg-Landau model by the finite element method. The response of the
material depends on the values of the exterior field, the Ginzburg-Landau
parameter and the size of the domain.
The solution branches in the different regions of the bifurcation diagrams
are analyzed and open mathematical problems are mentioned.Comment: 16 page
Vortex phases in mesoscopic cylinders with suppressed surface superconductivity
Vortex structures in mesoscopic cylinder placed in external magnetic field
are studied under the general de Gennes boundary condition for the order
parameter corresponding to the suppression of surface superconductivity. The
Ginzburg-Landau equations are solved based on trial functions for the order
parameter for vortex-free, single-vortex, multivortex, and giant vortex phases.
The equilibrium vortex diagrams in the plane of external field and cylinder
radius and magnetization curves are calculated at different values of de Gennes
"extrapolation length" characterizing the boundary condition for the order
parameter. The comparison of the obtained variational results with some
available exact solutions shows good accuracy of our approach.Comment: RevTex, 11 pages, 10 figure
Ginzburg-Landau Theory for a p-Wave Sr_2RuO_4 Superconductor: Vortex Core Structure and Extended London Theory
Based on a two dimensional odd-parity superconducting order parameter for
Sr_2RuO_4 with p-wave symmetry, we investigate the single vortex and vortex
lattice structure of the mixed phase near H_{c1}. Ginzburg-Landau calculations
for a single vortex show a fourfold structure with an orientation depending on
the microscopic Fermi surface properties. The corresponding extended London
theory is developed to determine the vortex lattice structure and we find near
H_{c1} a centered rectangular vortex lattice. As the field is increased from
H_{c1} this lattice continuously deforms until a square vortex lattice is
achieved. In the centered rectangular phase the field distribution, as
measurable through \mu-SR experiments, exhibits a characteristic two peak
structure (similar to that predicted in high temperature and borocarbide
superconductors).Comment: 12 pages, 7 figure
- …