Experiments have shown that hole spins in p-type silicon can be polarized and retain their polarization for a surprisingly long time. Now researchers from Osaka University have performed a new experiment that directly probes the spin of the holes as they travel through p-type silicon. They have shown that holes in p-type silicon can preserve spin-based information and transport it over distances much longer than previously thought, and it means that p-type semiconductors can be used for spin transport and be the basis of Spintronics devices.
The researchers separated the process of spin injection and detection, and this allowed them to probe the spin of the holes after travelling through the material. They used the spin-pumping method to inject spins into their silicon sample, and did not apply an electric field, so the injected spins spread out under the injection contact by spin diffusion.