Scalable Trapped Ion Quantum Computation with a Probabilistic Ion-Photon   Mapping
  We propose a method for scaling trapped ions for large-scale quantum computation and communication based on a probabilistic ion-photon mapping. Deterministic quantum gates between remotely located trapped ions can be achieved through detection of spontaneously-emitted photons, accompanied by the local Coulomb interaction between neighboring ions. We discuss gate speeds and tolerance to experimental noise for different probabilistic entanglement schemes. 
L.-M. Duan, B. B. Blinov, D. L. Moehring, C. Monroe