  The dual superconductor picture of the QCD vacuum is thought to describe
various aspects of the strong interaction including confinement. Ordinary
superconductivity is described by the Ginzburg-Landau (GL) equation. In the
present work we show that it is possible to arrive at a GL-like equation from
pure SU(2) gauge theory. This is accomplished by using Abelian projection to
split the SU(2) gauge fields into an Abelian subgroup and its coset. The two
gauge field components of the coset part act as the effective, complex, scalar
field of the GL equation. The Abelian part of the SU(2) gauge field is then
analogous to the electromagnetic potential in the GL equation. An important
aspect of the dual superconducting model is for the GL Lagrangian to have a
spontaneous symmetry breaking potential, and the existence of Nielsen-Olesen
flux tube solutions. Both of these require a tachyonic mass for the effective
scalar field. Such a tachyonic mass term is obtained from the condensation of
ghost fields.
