



01407nas a2200157   4500008004100000245006700041210006700108260001400175490000700189520094200196100002201138700001701160700001901177700001601196856003701212       2011                        eng d00aFast and robust quantum computation with ionic Wigner crystals0 aFast and robust quantum computation with ionic Wigner crystals  c2011/4/150 v833 aWe present a detailed analysis of the modulated-carrier quantum phase gate implemented with Wigner crystals of ions confined in Penning traps. We elaborate on a recent scheme, proposed by two of the authors, to engineer two-body interactions between ions in such crystals. We analyze for the first time the situation in which the cyclotron (w_c) and the crystal rotation (w_r) frequencies do not fulfill the condition w_c=2w_r. It is shown that even in the presence of the magnetic field in the rotating frame the many-body (classical) Hamiltonian describing small oscillations from the ion equilibrium positions can be recast in canonical form. As a consequence, we are able to demonstrate that fast and robust two-qubit gates are achievable within the current experimental limitations. Moreover, we describe a realization of the state-dependent sign-changing dipole forces needed to realize the investigated quantum computing scheme.
1 aBaltrusch, J., D.1 aNegretti, A.1 aTaylor, J., M.1 aCalarco, T.  uhttp://arxiv.org/abs/1011.5616v200962nas a2200133   4500008004100000245005100041210005100092260001500143490000700158520059100165100001900756700001600775856003700791       2008                        eng d00aWigner crystals of ions as quantum hard drives0 aWigner crystals of ions as quantum hard drives  c2008/12/180 v783 aAtomic systems in regular lattices are intriguing systems for implementing ideas in quantum simulation and information processing. Focusing on laser cooled ions forming Wigner crystals in Penning traps, we find a robust and simple approach to engineering non-trivial 2-body interactions sufficient for universal quantum computation. We then consider extensions of our approach to the fast generation of large cluster states, and a non-local architecture using an asymmetric entanglement generation procedure between a Penning trap system and well-established linear Paul trap designs.
1 aTaylor, J., M.1 aCalarco, T.  uhttp://arxiv.org/abs/0706.1951v1