Kornher Thomas, Xiao Da-Wu, Xia Kangwei, Sardi Fiammetta, Zhao Nan, Kolesov Roman, Wrachtrup Jörg
3rd Institute of Physics, University of Stuttgart, 70569 Stuttgart, Germany.
Beijing Computational Science Research Center, Haidian District, Beijing 100193, China.
Phys Rev Lett. 2020 May 1;124(17):170402. doi: 10.1103/PhysRevLett.124.170402.
Rare-earth related electron spins in crystalline hosts are unique material systems, as they can potentially provide a direct interface between telecom band photons and long-lived spin quantum bits. Specifically, their optically accessible electron spins in solids interacting with nuclear spins in their environment are valuable quantum memory resources. Detection of nearby individual nuclear spins, so far exclusively shown for few dilute nuclear spin bath host systems such as the nitrogen-vacancy center in diamond or the silicon vacancy in silicon carbide, remained an open challenge for rare earths in their host materials, which typically exhibit dense nuclear spin baths. Here, we present the electron spin spectroscopy of single Ce^{3+} ions in a yttrium orthosilicate host, featuring a coherence time of T_{2}=124 μs. This coherent interaction time is sufficiently long to isolate proximal ^{89}Y nuclear spins from the nuclear spin bath of ^{89}Y. Furthermore, it allows for the detection of a single nearby ^{29}Si nuclear spin, native to the host material with ∼5% abundance. This study opens the door to quantum memory applications in rare-earth ion related systems based on coupled environmental nuclear spins, potentially useful for quantum error correction schemes.
晶体基质中与稀土相关的电子自旋是独特的材料体系，因为它们有可能在电信波段光子与长寿命自旋量子比特之间提供直接接口。具体而言，它们在固体中可通过光学手段访问的电子自旋与周围环境中的核自旋相互作用，是宝贵的量子存储资源。到目前为止，仅在少数稀核自旋浴场宿主系统（如金刚石中的氮空位中心或碳化硅中的硅空位）中展示了对附近单个核自旋的检测，而对于其宿主材料中通常呈现密集核自旋浴场的稀土来说，这仍然是一个悬而未决的挑战。在这里，我们展示了正硅酸钇基质中单个Ce³⁺离子的电子自旋光谱，其相干时间T₂ = 124 μs。这个相干相互作用时间足够长，能够将近端⁸⁹Y核自旋与⁸⁹Y的核自旋浴场隔离开来。此外，它还能检测到宿主材料中天然存在的、丰度约为5%的单个附近²⁹Si核自旋。这项研究为基于耦合环境核自旋的稀土离子相关系统中的量子存储应用打开了大门，这可能对量子纠错方案有用。
