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Robust Quantum Memory in a Trapped-Ion Quantum Network Node

ORAL

Abstract

Quantum networks can revolutionise the way in which we distribute and process information. Applications in the fields of cryptography, quantum computing, metrology, and fundamental physics will require the ability to store entangled states while further entanglement is generated across the network. Trapped-ion nodes connected via photonic links are an excellent candidate for realising such networks.

Here, we integrate a long-lived memory qubit into a mixed-species trapped-ion quantum network node [1]. Ion-photon entanglement, first generated with a network qubit in 88Sr+, is transferred to 43Ca+ with 0.977(7) fidelity and mapped to a robust memory qubit. We then entangle the network qubit with another photon, which does not affect the memory qubit. We perform quantum state tomography to show that the fidelity of ion-photon entanglement decays ~ 70 times slower on the memory qubit. Dynamical decoupling and sympathetic cooling further extends the storage time; we measure an ion-photon entanglement fidelity of 0.81(4) after 10 s.

[1] P. Drmota et al., arXiv:2210.11447 (2022)

Publication: Drmota et al., arXiv:2210.11447

Presenters

  • Dougal Main

    University of Oxford, The University of Oxford

Authors

  • Peter Drmota

    University of Oxford

  • Dougal Main

    University of Oxford, The University of Oxford

  • David P Nadlinger

    University of Oxford

  • Bethan C Nichol

    University of Oxford

  • Marius A Weber

    Oxford Ionics, University of Oxford

  • Ellis M Ainley

    University of Oxford

  • Ayush Agrawal

    University of Oxford

  • Raghavendra Srinivas

    University of Oxford/Oxford Ionics, University of Oxford

  • Gabriel Araneda

    University of Oxford

  • Chris J Ballance

    University of Oxford, University of Oxford/Oxford Ionics, Department of Physics, University of Oxford

  • David M Lucas

    University of Oxford