PRX Quantum (Mar 2023)

Coherent Control of a Nuclear Spin via Interactions with a Rare-Earth Ion in the Solid State

  • Mehmet T. Uysal,
  • Mouktik Raha,
  • Songtao Chen,
  • Christopher M. Phenicie,
  • Salim Ourari,
  • Mengen Wang,
  • Chris G. Van de Walle,
  • Viatcheslav V. Dobrovitski,
  • Jeff D. Thompson

DOI
https://doi.org/10.1103/PRXQuantum.4.010323
Journal volume & issue
Vol. 4, no. 1
p. 010323

Abstract

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Individually addressed Er^{3+} ions in solid-state hosts are promising resources for quantum repeaters, because of their direct emission in the telecom band and their compatibility with silicon photonic devices. While the Er^{3+} electron spin provides a spin-photon interface, ancilla nuclear spins could enable multiqubit registers with longer storage times. In this work, we demonstrate coherent coupling between the electron spin of a single Er^{3+} ion and a single I=1/2 nuclear spin in the solid-state host crystal, which is a fortuitously located proton (^{1}H). We control the nuclear spin using dynamical-decoupling sequences applied to the electron spin, implementing one- and two-qubit gate operations. Crucially, the nuclear spin coherence time exceeds the electron coherence time by several orders of magnitude, because of its smaller magnetic moment. These results provide a path toward combining long-lived nuclear spin quantum registers with telecom-wavelength emitters for long-distance quantum repeaters.