Individual addressing of trapped ions and coupling of motional and spin   states using rf radiation
  Individual electrodynamically trapped and laser cooled ions are addressed in frequency space using radio-frequency radiation in the presence of a static magnetic field gradient. In addition, an interaction between motional and spin states induced by an rf field is demonstrated employing rf-optical double resonance spectroscopy. These are two essential experimental steps towards realizing a novel concept for implementing quantum simulations and quantum computing with trapped ions. 
M. Johanning, A. Braun, N. Timoney, V. Elman, W. Neuhauser, Chr.   Wunderlich