Scalable quantum computing in diamond

Recent progress toward the development of scalable quantum computers based on nitrogen-vacancy (NV) color centers in diamond will be described. Scaling is accomplished through the long-range entanglement of few-qubit processing nodes using photons. Local operations within each processing node will be accomplished using electronically switchable dipole-dipole interactions. Significant progress has been made in the control of the optical transitions. enabling us to reach the level required to attempt long-range entanglement. In the meantime, long-term storage and two-qubit operations have been demonstrated using magnetic dipole-dipole coupling to proximal spins that are not nearest neighbors. Significantly, all the processing node demonstration were been done at room temperature where spin lifetimes were found to be exceptionally long.