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Coherence of qubits based on single Ca$^+$ ions

F. Schmidt-Kaler·S. Gulde·M. Riebe·T. Deuschle·A. Kreuter·G. Lancaster·C. Becher·J. Eschner·H. Haeffner·R. Blatt
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Abstract

Two-level ionic systems, where quantum information is encoded in long lived states (qubits), are discussed extensively for quantum information processing. We present a collection of measurements which characterize the stability of a qubit based on the $S_{1/2}$--$D_{5/2}$ transition of single $^{40}$Ca$^+$ ions in a linear Paul trap. We find coherence times of $\simeq$1 ms, discuss the main technical limitations and outline possible improvements.

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F. Schmidt-Kaler, S. Gulde, M. Riebe, T. Deuschle, A. Kreuter, G. Lancaster, C. Becher, J. Eschner, H. Haeffner, R. Blatt. 2002-11-11. Coherence of qubits based on single Ca$^+$ ions. https://doi.org/10.1088/0953-4075/36/3/319

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