Creation of nitrogen-vacancy (NV) centers at the nanoscale surface region in diamond, while retaining their excellent spin and optical properties, is essential for applications in quantum technology. Here, we demonstrate the extension of the spin-coherence time (T2), the stabilization of the charge state, and an improvement of the creation yield of NV centers formed by the ion-implantation technique at a depth of ∼15 nm in phosphorus-doped n-type diamond. The longest T2 of about 580 μs of a shallow NV center approaches the one in bulk diamond limited by the nuclear spins of natural abundant 13C. The averaged T2 in n-type diamond is over 1.7 times longer than that in pure non-doped diamond. Moreover, the stabilization of the charge state and the more than twofold improvement of the creation yield are confirmed. The enhancements for the shallow NV centers in an n-type diamond-semiconductor are significant for future integrated quantum devices.
@article{arxiv.2012.07201,
title = {Shallow NV centers augmented by exploiting n-type diamond},
author = {A. Watanabe and T. Nishikawa and H. Kato and M. Fujie and M. Fujiwara and T. Makino and S. Yamasaki and E. D. Herbschleb and N. Mizuochi},
journal= {arXiv preprint arXiv:2012.07201},
year = {2021}
}