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arXiv · 2509.03354

High-fidelity control of a $^{13}$C nuclear spin coupled to a tin-vacancy center in diamond

Jeremias Resch·Ioannis Karapatzakis·Mohamed Elshorbagy·Marcel Schrodin·Philipp Fuchs·Philipp Graßhoff·Luis Kussi·Christoph Sürgers·Cyril Popov·Christoph Becher·Wolfgang Wernsdorfer·David Hunger
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Abstract

Nuclear spins near group-IV defects in diamond are promising candidates for quantum memories in quantum network applications. Here, we demonstrate high-fidelity control of a single $^{13}$C nuclear spin coupled to a tin-vacancy (SnV) center in diamond. We perform a combination of optical and microwave pumping to achieve initialization into a combined electro-nuclear spin state with a fidelity of $99.74(3)\,\%$. Harnessing a superconducting waveguide for radio-frequency driving, we demonstrate precise nuclear spin control: Ramsey measurements reveal a coherence time of $T_2^* = 1.5(1)\,$milliseconds, and we use dynamical decoupling to extend it to $1.35(3)\,$seconds. We perform randomized benchmarking, yielding a single-qubit gate fidelity of $99.92(1)\,\%$. This demonstrates a coherent spin-photon system with promising properties for quantum network nodes.

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Jeremias Resch, Ioannis Karapatzakis, Mohamed Elshorbagy, Marcel Schrodin, Philipp Fuchs, Philipp Graßhoff, Luis Kussi, Christoph Sürgers, Cyril Popov, Christoph Becher, Wolfgang Wernsdorfer, David Hunger. 2025-09-03. High-fidelity control of a $^{13}$C nuclear spin coupled to a tin-vacancy center in diamond. https://doi.org/10.1103/bmc6-qvwq

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