Equilibrium topology of the intermediate state in type-I superconductors of different shapes

TitleEquilibrium topology of the intermediate state in type-I superconductors of different shapes
Publication TypeJournal Article
Year of Publication2007
AuthorsProzorov R
Journal TitlePhysical Review Letters
Volume98
Pages257001
Date PublishedJun
Type of ArticleArticle
ISBN Number0031-9007
Accession NumberISI:000247469400043
Keywordsmagnetization, SLAB
Abstract

A high-resolution magneto-optical technique was used to analyze flux patterns in the intermediate state of bulk Pb samples of various shapes-cones, hemispheres, and discs. Combined with the measurements of macroscopic magnetization, these results allowed studying the effect of bulk pinning and geometric barrier on the equilibrium structure of the intermediate state. Zero-bulk pinning discs and slabs show hysteretic behavior due to topological hysteresis-flux tubes on penetration and lamellae on flux exit. (Hemi)spheres and cones do not have a geometric barrier and show no hysteresis with flux tubes dominating the intermediate field region in both regimes. It is concluded that flux tubes represent the equilibrium topology of the intermediate state. Real-time video is available in the EPAPS Document No. E-PRLTAO-98-024726..

DOI10.1103/PhysRevLett.98.257001
Alternate JournalPhys. Rev. Lett.