Researchers from the Japanese RIKEN institute have shown that spin information in some materials can travel much further than previously thought. The researchers managed to measure the spin diffusion in detail by using two magnetic contacts to inject the spin signal into a thin silver wire. This enhances the amount of spin polarization present in the wire. Using a third contact that picks the signals, they were manage to manage the polarization degree at several distances along the wire.
They say that spin current was detected at distances of over ten micrometers. The absolute magnitude of the spin signal decreases with travel distance, but the quality of the spin precession signal (coherence) is actually improved - due to the fact that the collective coherent precession of the spins has a beneficial effect on the overall spin polarization over time.