The negatively charged tin-vacancy center in diamond (SnV−) is an emerging platform for building the next generation of long-distance quantum networks. This is due to the SnV−’s favorable optical and spin properties including bright emission, insensitivity to electronic noise, and long spin coherence times at temperatures above 1 K. Here, we demonstrate measurement of a single SnV− electronic spin with a single-shot readout fidelity of 87.4%, which can be further improved to 98.5% by conditioning on multiple readouts. In the process, we develop understanding of the relationship between strain, magnetic field, spin readout, and microwave spin control. We show that high-fidelity readout is compatible with rapid microwave spin control, demonstrating a favorable parameter regime for use of the SnV− center as a high-quality spin-photon interface. Finally, we use weak quantum measurement to study measurement-induced dephasing; this illuminates the fundamental interplay between measurement and decoherence in quantum mechanics, and provides a universal method to characterize the efficiency of color-center spin readout. Taken together, these results overcome an important hurdle in the development of the SnV−-based quantum technologies and, in the process, develop techniques and understanding broadly applicable to the study of solid-state quantum emitters.

中文翻译：

---

金刚石中锡空位量子比特的单次读出和弱测量


金刚石中带负电荷的锡空位中心 （SnV−） 是构建下一代长距离量子网络的新兴平台。这是由于 SnV− 具有良好的光学和自旋特性，包括明亮发射、对电子噪声不敏感以及在 1 K 以上的温度下的长自旋相干时间。在这里，我们演示了单次 SnV− 电子自旋的测量，单次读出保真度为 87.4%，可以通过对多个读出进行调节，进一步提高到 98.5%。在此过程中，我们加深了对应变、磁场、自旋读数和微波自旋控制之间关系的理解。我们表明高保真读出与快速微波自旋控制兼容，证明了将 SnV− 中心用作高质量自旋光子界面的有利参数制度。最后，我们使用弱量子测量来研究测量诱导的移相;这阐明了量子力学中测量和退相干之间的基本相互作用，并提供了一种通用方法来表征色心自旋读数的效率。综上所述，这些结果克服了基于 SnV− 的量子技术发展中的一个重要障碍，并在此过程中开发了广泛适用于固态量子发射器研究的技术和理解。