  We discuss the Pauli Hamiltonian within a ${SU(2)}$ gauge theory
interpretation, where the gauge symmetry is broken. This interpretation carries
directly over to the structural inversion asymmetric spin-orbit interactions in
semiconductors and offers new insight into the problem of spin currents in the
condensed matter environment. The central results is that symmetry breaking
leads to zero spin conductivity in contrast to predictions of Gauge symmetric
treatments. Computing the translation operator commutation relations comprising
the simplest possible structural inversion asymmetry due to an external
electric field, we derive a new condition for orbit quantization. The relation
between the topological nature of this effect is consistent with our
non-Abelian gauge symmetry breaking scenario.
