  We apply duality transformation to the Abelian Higgs model in 3+1 dimensions
in the presence of electrons coupled to the gauge field. The Higgs field is in
the symmetry broken phase, where flux strings can form. Dualization brings in
an antisymmetric tensor potential $B_{\mu\nu}\,$, which couples to the
electrons through a nonlocal interaction which can be interpreted as a coupling
to the spin current. It also couples to the string worldsheet and gives rise to
a string Higgs mechanism via the condensation of flux strings. In the phase
where the $B_{\mu\nu}$ field is massless, the nonlocal interaction implies a
linearly rising attractive force between the electrons, which can be
interpreted as the result of a pair of strings joining the electrons.
