Quantum Computing on Multi-atomic Ensembles in Quantum Electrodynamics   Cavity
  We propose an effective realization of a complete set of elementary quantum gates in the solid-state quantum computer based on the multi-atomic coherent (MAC-) ensembles in the QED cavity. Here, we use the two-ensemble qubit encoding and swapping-based operations that together provide implementation of any encoded single-qubit operation by three elementary gates and the encoded controlled-NOT operation is performed in a single step. This approach simplifies a physical realization of universal quantum computing and adds the immunity to a number of errors. We also demonstrate that the proposed architecture of quantum computer satisfies DiVincenzo criteria. 
Farid Ablayev, Sergey N. Andrianov, Alexander Vasiliev, and Sergey A.   Moiseev
quant-ph