AI 中文总结
本研究在同位素纯化$^{28}$Si中表征单电离间隙铝施主，首次观测到电信波段硅色心激发态的光学分辨超精细结构，为量子网络等领域提供了新平台。
AI 中文摘要
硅中的核自旋量子比特具备极高的相干量子存储性能，光耦合自旋是量子网络与分布式量子计算的理想平台。已有研究提出，具有抗磁性基态的发射体可通过亚稳态超精细耦合激发态实现核自旋存储器的光接口，同时抑制主要退相干源。此前，硅色心中合适跃迁的直接光学观测一直未能实现。本研究在同位素纯化的$^{28}$Si中表征单电离间隙铝施主（Al$_\text{i}^+$），发现该研究较少的缺陷的若干新特征：测量到明亮发射与强光学跃迁，与此前对该中心的研究不同，将其发射归因于最低能量1s:T$_2$激发态的交换分裂自旋三重态与单重态能级；测量了激发态寿命，且因发射线宽窄，观测到长寿命三重态的精细与超精细结构，这是电信波段硅色心激发态中光学分辨超精细结构的首次测量。
英文摘要
Nuclear spin qubits in silicon offer exceptionally coherent quantum memory, and optically-interfaced spins are a promising platform for both quantum networking and distributed quantum computing. It has been proposed that emitters with diamagnetic ground states may permit an optical interface to nuclear spin memories via metastable, hyperfine-coupled excited states while suppressing key sources of decoherence. Until now, direct optical observation of suitable transitions in silicon colour centres has remained elusive. Here we characterize the singly-ionized interstitial aluminum donor (Al$_\mathrm{i}^+$) in isotopically purified $^{28}$Si and find several novel features of this little-studied defect. We measure bright emission and strong optical transitions and, in contrast to previous studies of this centre, attribute its emission to an exchange-split spin triplet and singlet level of the lowest-energy 1s:T$_2$ excited state. We measure the excited-state lifetimes and, as a consequence of its narrow emission linewidth, observe the fine and hyperfine structure of the long-lived triplet state. This constitutes the first measurement of an optically-resolved hyperfine structure in the excited state of a telecommunications-band silicon colour centre.
Comments5 pages, 4 figures
