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arXiv · 2207.13128

Robust multi-qubit quantum network node with integrated error detection

Pieter-Jan Stas·Yan Qi Huan·Bartholomeus Machielse·Erik N. Knall·Aziza Suleymanzade·Benjamin Pingault·Madison Sutula·Sophie W. Ding·Can M. Knaut·Daniel R. Assumpcao·Yan-Cheng Wei·Mihir K. Bhaskar·Ralf Riedinger·Denis D. Sukachev·Hongkun Park·Marko Lončar·David S. Levonian·Mikhail D. Lukin
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Abstract

Long-distance quantum communication and networking require quantum memory nodes with efficient optical interfaces and long memory times. We report the realization of an integrated two-qubit network node based on silicon-vacancy centers (SiVs) in diamond nanophotonic cavities. Our qubit register consists of the SiV electron spin acting as a communication qubit and the strongly coupled 29Si nuclear spin acting as a memory qubit with a quantum memory time exceeding two seconds. By using a highly strained SiV with suppressed electron spin-phonon interactions, we realize electron-photon entangling gates at elevated temperatures up to 1.5 K and nucleus-photon entangling gates up to 4.3 K. Finally, we demonstrate efficient error detection in nuclear spin-photon gates by using the electron spin as a flag qubit, making this platform a promising candidate for scalable quantum repeaters.

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Pieter-Jan Stas, Yan Qi Huan, Bartholomeus Machielse, Erik N. Knall, Aziza Suleymanzade, Benjamin Pingault, Madison Sutula, Sophie W. Ding, Can M. Knaut, Daniel R. Assumpcao, Yan-Cheng Wei, Mihir K. Bhaskar, Ralf Riedinger, Denis D. Sukachev, Hongkun Park, Marko Lončar, David S. Levonian, Mikhail D. Lukin. 2022-07-26. Robust multi-qubit quantum network node with integrated error detection. https://doi.org/10.1126/science.add9771

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