  Aharonov-Bohm (AB) and Aharonov-Casher (AC) effects are treated fully
relativistically in 2+1 dimensions. The influences of the relevant geometric
and topological phases on an entangled spin-1/2 system are studied. It is shown
that for the AC case the correlation function of the Clauser-Horne-Shimony-Holt
(CHSH) inequality for certain choices of the spin measurements depends on the
AC phase explicitly.
