Entangling two and more ions with collective laser-ion interactions
Christian F. Roos, Gerhard Kirchmair, F. Zähringer, Jan Benhelm, R. Gerritsma, R. Blatt · 2009
Laser-ion interactions that collectively couple the pseudo-spins of a string of trapped ions to one of the string's vibrational modes [1] have been used by us to entangle a pair of40Ca+ions with very high fidelity [2–4]. In addition, we experimentally confirmed that this gate mechanism allows for entangling ions without having recourse to ground state cooling [3]. This opens the way to performing an entangling gate after having applied an operation which does not preserve the ions' motional state like for example state detection.