  We present a theory for spin selective Aharonov-Bohm oscillations in a
lateral triple quantum dot. We show that to understand the Aharonov-Bohm (AB)
effect in an interacting electron system within a triple quantum dot molecule
(TQD) where the dots lie in a ring configuration requires one to not only
consider electron charge but also spin. Using a Hubbard model supported by
microscopic calculations we show that, by localizing a single electron spin in
one of the dots, the current through the TQD molecule depends not only on the
flux but also on the relative orientation of the spin of the incoming and
localized electrons. AB oscillations are predicted only for the spin singlet
electron complex resulting in a magnetic field tunable "spin valve".
