High fidelity quantum gates for ion qubits in optical transitions

ORAL

Abstract

One of the most important challenges in ion trap quantum computing is the implementation of a high fidelity two--qubit quantum gate. For hyperfine qubits state dependend AC--Stark shifts were used to demonstrate a two qubit gate with a fidelity of 0.97 [1]. Here, we show that similar forces can also be employed for qubits based on optical transitions as for instance the $S_{1/2} \rightarrow D_{5/2}$ transition in Calcium. In contrast to previous work, our proposal can be applied to magnetic--field insensitive transitions. It also allows for negligible spontaneous emission rates and can be implemented with a pair of co--propagating beams. According to simulations with current experimental imperfections, the proposed gate will allow for fidelities exceeding 0.99. \newline \newline [1] D. Leibfried, {\it et al.}, Nature {\bf 422}, 412 (2003).

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Authors

  • Kihwan Kim

    • Institute fuer Experimentalphysik, Universiaet Innsbruck

  • Mark Riebe

    • Institute fuer Experimentalphysik, Universiaet Innsbruck

  • Michael Chwalla

    • Institute fuer Experimentalphysik, Universiaet Innsbruck

  • Thomas Monz

    • Institute fuer Experimentalphysik, Universiaet Innsbruck

  • Philipp Schindler

    • Institute fuer Experimentalphysik, Universiaet Innsbruck

  • Wolfgang Haensel

    • Institute fuer Experimentalphysik, Universiaet Innsbruck

  • Piet Schmidt

    • Institute fuer Experimentalphysik, Universiaet Innsbruck

  • Christian Roos

    • Institut fuer Quantenoptik und Quanteninformation

  • Hartmut Haeffner

    • Institut fuer Quantenoptik und Quanteninformation

  • Jan Benhelm

    • Institut fuer Quantenoptik und Quanteninformation

  • Gerhard Kirchmair

    • Institut fuer Quantenoptik und Quanteninformation

  • Timo Koerber

    • Institut fuer Quantenoptik und Quanteninformation

  • Rainer Blatt

    • Institut fuer Quantenoptik und Quanteninformation

  • Leandro Aolita

    • Instituto de Fisica, Universidade Federal do Rio de Janeiro