Nuclear spins in the solid state are both a cause of decoherence and a valuable resource for spin qubits. In this work, we demonstrate control of isolated ²⁹Si nuclear spins in silicon carbide (SiC) to create an entangled state between an optically active divacancy spin and a strongly coupled nuclear register. We then show how isotopic engineering of SiC unlocks control of single weakly coupled nuclear spins and present an ab initio method to predict the optimal isotopic fraction that maximizes the number of usable nuclear memories. We bolster these results by reporting high-fidelity electron spin control (F = 99.984(1)%), alongside extended coherence times (Hahn-echo T₂ = 2.3 ms, dynamical decoupling T₂^DD > 14.5 ms), and a >40-fold increase in Ramsey spin dephasing time (T₂*) from isotopic purification. Overall, this work underlines the importance of controlling the nuclear environment in solid-state systems and links single photon emitters with nuclear registers in an industrially scalable material.

固态核自旋既是引起退相干的原因，又是自旋量子比特的宝贵资源。在这项工作中，我们演示了在碳化硅（SiC）中控制孤立的²⁹ Si核自旋以在旋光性空位自旋和强耦合核寄存器之间产生纠缠态的控制。然后，我们展示了SiC的同位素工程技术如何解锁单个弱耦合核自旋的控制，并提出了一种从头算的方法来预测最佳的同位素分数，从而使可用的核存储器数量最大化。我们通过报告高保真电子自旋控制（F  = 99.984（1）％），以及延长的相干时间（Hahn-echo T ₂  = 2.3 ms，动态去耦T ₂ ^DD）来支持这些结果 > 14.5毫秒），并且通过同位素纯化得到的拉姆西自旋移相时间（T ₂ *）增加了40倍以上。总的来说，这项工作强调了控制固态系统中核环境的重要性，并将单光子发射器与工业可扩展材料中的核寄存器联系起来。