# Sign change of surface energy and stability of composite vortex in two-component superconductivity - Condensed Matter > Superconductivity

Sign change of surface energy and stability of composite vortex in two-component superconductivity - Condensed Matter > Superconductivity - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Abstract: Existence of thermodynamically stable composite vortices in a two-componentsuperconductor may form distinctive vortex patterns, and may lead to type-1.5superconductivity. Here we study the surface energy of the two-componentsuperconductor and show that the sign of surface energy is determined not onlyby the Ginzburg-Landau parameters $\kappa i i=1,2$ of two superconductingcomponents, but also by a temperature independent parameter $\kappa \xi$,which is defined as the ratio of the coherence lengths of two components. Sincethe negative surface energy conduces to the invasion of thermodynamicallystable composite vortices into a superconductor, the criterions for stabilityof composite vortex are these three independent dimensionless parameters. Wefind that there can exist thermodynamically stable composite vortex in atype-1+type-2 or type-2+type-2 material. We also predict that unusual vortexpatterns like those observed in $MgB 2$ V. Moshchalkov et al, Phys. Rev.Lett., 102, 117001 2009 can occur in some type-2+type-2 superconductors.

Autor: Jun-Ping Wang

Fuente: https://arxiv.org/