Quantum information processing in diamond
  Quantum computing is an attractive and multidisciplinary field, which became a focus for experimental and theoretical research during last decade. Among other systems, like ions in traps or superconducting circuits, solid-states based qubits are considered to be promising candidates for first experimental tests of quantum hardware. Here we report recent progress in quantum information processing with point defect in diamond. Qubits are defined as single spin states (electron or nuclear). This allows exploring long coherence time (up to seconds for nuclear spins at cryogenic temperatures). In addition, the optical transition between ground and excited electronic states allows coupling of spin degrees of freedom to the state of the electromagnetic field. Such coupling gives access to the spin state readout via spin-selective scattering of photon. This also allows using of spin state as robust memory for flying qubits (photons). 
F. Jelezko, J. Wrachtrup