Vanadium in silicon carbide (SiC) is emerging as an important candidate system for quantum technology due to its optical transitions in the telecom wavelength range. However, several key characteristics of this defect family including their spin relaxation lifetime (T₁), charge state dynamics, and level structure are not fully understood. In this work, we determine the T₁ of an ensemble of vanadium defects, demonstrating that it can be greatly enhanced at low temperature. We observe a large spin contrast exceeding 90% and long spin-relaxation times of up to 25 s at 100 mK, and of order 1 s at 1.3 K. These measurements are complemented by a characterization of the ensemble charge state dynamics. The stable electron spin furthermore enables high-resolution characterization of the systems’ hyperfine level structure via two-photon magneto-spectroscopy. The acquired insights point towards high-performance spin-photon interfaces based on vanadium in SiC.

中文翻译：

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碳化硅中的钒：具有长弛豫寿命和超精细分辨率光学跃迁的电信级旋转中心


碳化硅 (SiC) 中的钒由于其在电信波长范围内的光学跃迁而成为量子技术的重要候选系统。然而，该缺陷族的几个关键特征，包括其自旋弛豫寿命 (T ₁ )、电荷态动力学和能级结构尚未完全了解。在这项工作中，我们确定了钒缺陷集合的 T ₁ ，证明它可以在低温下大大增强。我们观察到超过 90% 的大自旋对比度和在 100 mK 下长达 25 s 的长自旋弛豫时间，在 1.3 K 下为 1 s 的量级。这些测量得到了整体电荷态动力学表征的补充。稳定的电子自旋还可以通过双光子磁谱对系统的超精细结构进行高分辨率表征。所获得的见解指向基于碳化硅中钒的高性能自旋光子界面。