Spin polarization oscillations without spin precession: spin-orbit entangled resonances in quasi-one-dimensional spin transport

Resonant behavior involving spin-orbit entangled states occurs for spin transport along a narrow channel defined in a two-dimensional electron gas, including an apparent rapid relaxation of the spin polarization for special values of the channel width and applied magnetic field (so-called ballistic spin resonance). A fully quantum mechanical theory for transport through multiple subbands of the one-dimensional system provides the dependence of the spin transport on the applied magnetic field and channel width, including a resonant depolarization of spins when the Zeeman energy matches the subband energy splittings and a spin texture transverse to the magnetic field. The resonance phenomenon is robust to disorder.