  We report the detection of spin interference signal in an Aharonov-Bohm type
interferometer with quantum dots on the conduction paths. We have found that
resonators like quantum dots can work as efficient spin rotators. The
interference signal appears only when spin-polarized electrons are injected
into the device. The interference pattern in the gate voltage-magnetic field
plane is checker board like, ensuring the modulation of spin wavefunction's
phase as well as the orbital phase.
