Polarizing Nuclear Spins in Silicon Carbide

Quantum computers and other quantum information processing (QIP) devices—such as simulators, sensors, and communication channels—hold the promise to deliver performances not attainable by classical systems. Unfortunately, the qubits used to store information are usually fragile and difficult to manipulate and engineer, thus forestalling advances in the field. Many qubit candidates suffer from short coherence times due to interactions with the environment. In this regard, spin-1/2 nuclei are an attractive qubit system, as they are quite insensitive to external degrees of freedom that cause decoherence. However, this insensitivity also makes it challenging to initialize and manipulate nuclear spins. An international team of researchers led by David Awschalom of the University of Chicago, Illinois, has managed to polarize nuclear spins in silicon carbide (SiC) using optical light [1]. This is not the first time this sort of spin control has been demonstrated, but compared to previous materials, SiC has many practical advantages, such as being inexpensive to grow and fabricate into tiny structures. The results are therefore an important step in making nuclear spins a viable contender for scalable quantum computation.