Spin-dependent electron interferometry

We use interference of electron waves in a quantum well to switch the spin polarization of electrons. The spin quantum resonator consists of a Cu-film of variable thickness sandwiched between vacuum and a magnetic Co-film. Electrons are injected into the resonator from the vacuum side. The Co-film provides a spin dependent reflector. Varying the resonator thickness results in periodic modulation of the spin polarization of the incoming electrons. We use spin interferometry to measure the divergence of the period of interlayer exchange coupling upon approaching a zone boundary. We propose that interferometric spin selection should be observable in spin polarized scanning tunneling spectroscopy.