Single color centers in solid have emerged as promising physical platforms for quantum information science. Creating these centers with excellent quantum properties is a key foundation for further technological developments. In particular, the microscopic understanding of the spin bath environments is the key to engineer color centers for quantum control. In this work, we propose and demonstrate a distinct high-temperature annealing (HTA) approach for creating high-quality nitrogen vacancy (NV) centers in implantation-free diamonds. Simultaneously using the created NV centers as probes for their local environment we verify that no damage was microscopically induced by the HTA. Nearly all single NV centers created in ultra-low-nitrogen-concentration membranes possess stable and Fourier-transform-limited optical spectra. Furthermore, HTA strongly reduces noise sources naturally grown in ensemble samples, and leads to more than three-fold improvements of decoherence time and sensitivity. We also verify that the vacancy activation and defect reformation, especially H3 and P1 centers, can explain the reconfiguration between spin baths and color centers. This novel approach will become a powerful tool in vacancy-based quantum technology.
@article{arxiv.2208.09691,
title = {Microscopic study of optically-stable, coherent color centers in diamond generated by high-temperature annealing},
author = {King Cho Wong and San Lam Ng and Kin On Ho and Yang Shen and Jiahao Wu and Kwing To Lai and Man Yin Leung and Wai Kuen Leung and Durga Bhaktavatsala Rao Dasari and Andrej Denisenko and Jörg Wrachtrup and Sen Yang},
journal= {arXiv preprint arXiv:2208.09691},
year = {2022}
}