Applied Physics B

, 122:89 | Cite as

A quantum repeater node with trapped ions: a realistic case example

  • A. D. PfisterEmail author
  • M. Salz
  • M. Hettrich
  • U. G. Poschinger
  • F. Schmidt-Kaler
Part of the following topical collections:
  1. Quantum Repeaters: From Components to Strategies


We evaluate the feasibility of the implementation of two quantum repeater protocols with an existing experimental platform based on a \(^{40}\hbox {Ca}^+\)-ion in a segmented microtrap, and a third one that requires small changes to the platform. A fiber cavity serves as an ion–light interface. Its small mode volume allows for a large coupling strength of \(g_c = 2 \pi \times 20\) MHz despite comparatively large losses \(\kappa = 2\pi \times 18.3\) MHz. With a fiber diameter of \(125\,\upmu \hbox {m}\), the cavity is integrated into the microstructured ion trap, which in turn is used to transport single ions in and out of the interaction zone in the fiber cavity. We evaluate the entanglement generation rate for a given fidelity using parameters from the experimental setup. The DLCZ protocol (Duan et al. in 414:413–418, 2001) and the hybrid protocol (van Loock et al. in 96:240501, 2006) outperform the EPR protocol (Sangouard et al. in 15(8):085004, 2013). We calculate rates of more than \(100\,\hbox {s}^{-1}\) for non-local Bell state fidelities larger than 0.95 with the existing platform. We identify parameters which mainly limit the attainable rates, and conclude that entanglement generation rates of \(750\,\hbox {s}^{-1}\) at fidelities of 0.95 are within reach with current technology.


Success Probability Bell State Stationary Qubit Mode Match Hybrid Protocol 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



We thank Peter van Loock, Denis Gonta and Pascal Eich for helpful discussions. We acknowledge financial support by the European commission within the IP SIQS and by the Bundesministerium für Bildung und Forschung via IKT 2020 (


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© Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  1. 1.QUANTUM, Institut für PhysikJohannes Gutenberg UniversitätMainzGermany

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