Article

Experimental protocol for high-fidelity heralded photon-to-atom quantum state transfer

  • Nature Communications 5, Article number: 5527 (2014)
  • doi:10.1038/ncomms6527
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Abstract

A quantum network combines the benefits of quantum systems regarding secure information transmission and calculational speed-up by employing quantum coherence and entanglement to store, transmit and process information. A promising platform for implementing such a network are atom-based quantum memories and processors, interconnected by photonic quantum channels. A crucial building block in this scenario is the conversion of quantum states between single photons and single atoms through controlled emission and absorption. Here we present an experimental protocol for photon-to-atom quantum state conversion, whereby the polarization state of an absorbed photon is mapped onto the spin state of a single absorbing atom with >95% fidelity, while successful conversion is heralded by a single emitted photon. Heralded high-fidelity conversion without affecting the converted state is a main experimental challenge, in order to make the transferred information reliably available for further operations. We record >80 s−1 successful state transfer events out of 18,000 s−1 repetitions.

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Acknowledgements

We acknowledge support by the BMBF (QuOReP project, QSCALE Chist-ERA project) and the German Scholars Organization/Alfried Krupp von Bohlen und Halbach-Stiftung.

Author information

Affiliations

  1. Universität des Saarlandes, Experimentalphysik, Campus E2 6, 66123 Saarbrücken, Germany

    • Christoph Kurz
    • , Michael Schug
    • , Pascal Eich
    • , Jan Huwer
    • , Philipp Müller
    •  & Jürgen Eschner

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Contributions

C.K., M.S. and P.E. contributed equally to this work; J.H. set up the narrow-band laser; C.K., M.S. and P.E. prepared the experiment and acquired and analyzed the data; P.M. performed numerical calculations; J.E. planned and supervised the project; C.K. and J.E. wrote the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Christoph Kurz.

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