  An electron interferometer was designed and fabricated via a normal
metal/insulator/ferromagnet non-local lateral spin valve with a ring-shaped
normal metal/insulator spacer, and spin current interference was observed. A
very high spin signal of 200 m$\Omega$ was found in a device with 2 $\mu$m
injector-detector distance and magnetic field swept parallel to the plane. With
a perpendicular magnetic field sweep, a Hanle effect measurement showed both
spin precession and $h/e$ oscillation. Because of the non-adiabatic nature of
the precessing spins at low fields as they traverse the normal metal ring, this
is an experimental observation of Aharonov-Anandan's non-adiabatic geometric
phase. In addition, our observation of identical spin resistance for normal and
superconducting Aluminum is inconsistent with theoretical predictions based on
the quasiparticle picture. To explain the superconducting spin current we
suggest that spin triplet Cooper pairs may exist in thin films of Aluminum for
direct spin injection.
