Revealing the properties of single spin defects in solids is essential for quantum applications based on solid-state systems. However, it is intractable to investigate the temperature-dependent properties of single defects, due to the low precision for single-defect measurements in contrast to defect ensembles. Here we report that the temperature dependence of the Hamiltonian parameters for single negatively charged nitrogen-vacancy (NV−) centers in diamond is precisely measured, and the results find a reasonable agreement with first-principles calculations. Particularly, the hyperfine interactions with randomly distributed 13C nuclear spins are clearly observed to vary with temperature, and the relevant coefficients are measured with Hz-level precision. The temperature-dependent behaviors are attributed to both thermal expansion and lattice vibrations by first-principles calculations. Our results pave the way for taking nuclear spins as more stable thermometers at nanoscale. The methods developed here for high-precision measurements and first-principles calculations can be further extended to other solid-state spin defects.
@article{arxiv.2212.02849,
title = {Temperature-dependent behaviors of single spin defects in solids determined with Hz-level precision},
author = {Shaoyi Xu and Mingzhe Liu and Tianyu Xie and Zhiyuan Zhao and Qian Shi and Pei Yu and Chang-Kui Duan and Fazhan Shi and Jiangfeng Du},
journal= {arXiv preprint arXiv:2212.02849},
year = {2022}
}