Saroj Dash and colleagues at the University of Twente in the Netherlands have demonstrated the injection and detection of spin in silicon at room temperature, together with its control via a weak magnetic field.
Polarized electrons or holes enter and leave silicon from conducting ferromagnets via tunnelling, retaining spin lifetimes of 140 ps in n-type silicon and 270 ps in p-type silicon, with drift distances large enough to make interesting devices possible. Previous injection and detection of spins in non-magnetic semiconductors has been restricted to n-type materials below 150 K.