Osnabrück 2002 – scientific programme
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Q: Quantenoptik
Q 113: Quantum Computing
Q 113.1: Talk
Monday, March 4, 2002, 14:00–14:15, HS 11/215
Heterogeneous magnesium-indium ion chain for quantum computation — •Volker Ludsteck, Steffen Köhler, Hoi Nok Tsao, Wolfgang Lange, and Herbert Walther — Max-Planck-Institut für Quantenoptik, Garching, Germany
Linear chains of ions in a radio frequency trap are ideally suited for performing quantum information processing. The ions take over different tasks: two internal electronic states are used for storing quantum information. The thermal motion of the ions is reduced by means of laser cooling, which is a precondition for vibrational coupling of the qubits. For long-distance transmission of qubits, strong coupling to the photonic field is necessary. Since a single ion species cannot meet all requirements equally well, we propose to use a heterogeneous chain. Two hyperfine ground states of 25Mg+ ions are used as the carriers of quantum information. An ideal candidate for cooling is 115In+, since it offers a transition narrow enough for resolved sideband cooling but strong enough for a high cooling rate [1]. Embedding a few indium ions in the chain is sufficient to provide sympathetic cooling for the entire chain. The laser exciting the indium transition does not affect the internal states of magnesium. Therefore, cooling and computation dynamics are completely decoupled, allowing continuous cooling.
[1] E. Peik, J. Abel, Th. Becker, J. von Zanthier, H. Walther, Phys. Rev. A 60, 439 (1999).