Magnetic field delocalization and flux inversion in fractional vortices in two-component superconductors.

We demonstrate that, in contrast with the single-component Abrikosov vortex, in two-component superconductors vortex solutions with an exponentially screened magnetic field exist only in exceptional cases: in the case of vortices carrying an integer number of flux quanta and in a special parameter limit for half-quantum vortices. For all other parameters, the vortex solutions have a delocalized magnetic field with a slowly decaying tail. Furthermore, we demonstrate a new effect which is generic in two-component systems but has no counterpart in single-component systems: on exactly half of the parameter space of the U(1) x U(1) Ginzburg-Landau model, the magnetic field of a generic fractional vortex inverts its direction at a certain distance from the vortex core.