Coherent site-resolved control between nuclear spin ground states and Rydberg states in ⁸⁷Sr

Neutral atom arrays have emerged as a promising platform for scalable quantum computation. Recently we have demonstrated a quantum register based on nuclear spin ground states in ⁸⁷Sr, with second-long coherence times and single-qubit gates with a fidelity > 99%. Exploiting the interaction between atoms in highly-excited Rydberg states allows fast, high fidelity multi-qubit gates. Here we present coherent manipulations between a strontium 87 nuclear-spin ground state and a Rydberg state. Our two-photon excitation scheme, based on the single-qubit operation infrastructure and tightly focused UV beams, readily offers site selectivity, which allows individual multi-qubit control. We characterize the coherence and interaction properties, improve the performance with simulations, and explore the future prospects of this system.