Fractional Flux Vortices in Mesoscopic Two-Component Superconductors

Conventional superconductors have vortices carrying integer multiples of magnetic flux quantum while unconventional ones, with p- or d-wave order parameter, allow half-integer fluxes. In this presentation we show that mesoscopic size effects stabilize fractional flux vortices in the \textit{thermodynamical ground state} of s-wave two-gap superconductors. The value of these fluxes can be an \textit{arbitrary fraction of flux quantum} and can be measured directly from distributions of magnetic fields on the samples.