Electrostatics of vortices in type-II superconductors

In a type-II superconductor the gap variation in the core of a vortex line induces a local charge modulation. Accounting for metallic screening, we determine the line charge of individual vortices and calculate the electric field distribution in the half space above a field penetrated superconductor. The resulting field is that of an atomic size dipole d similar to ea(B) (z) over cap, a(B) = h(2)/me(2) is the Bohr radius, acting on a force microscope in the pico- to femto-Newton range.