Silicon spintronics at room temperature

Abstract

The electrical injection and detection of spin-polarized carriers in semiconductors at room temperature has been one of the key challenges in spintronics. Exploiting spin functionality in silicon, the dominant electronic material, is particularly crucial in order to realize the next generation of information processing devices based on spin. Here we present our recent demonstration of electrical spin injection into n-type and p-type silicon from a ferromagnetic tunnel contact, the spin manipulation via the Hanle effect, and the electrical detection of the induced spin accumulation, all at room temperature. A control experiment that makes use of a non-magnetic nanolayer inserted between the ferromagnet and the tunnel barrier supports the data, proving spin injection and excluding any spurious signals. We also report Hanle effect measurements in two-terminal geometry and show that in this configuration the Hanle signal is always dominated by spin accumulation below the two individual contacts, rather than spin transport from injector to detector through the semiconductor channel. The results provide many new insights and open a platform for further exploration of spin functionality in complementary silicon devices operating at ambient temperature.