Decoherence of diamond NV ensembles with varying nitrogen spin concentration: a cluster expansion study

Nitrogen-vacancy (NV) centers in diamond have been developed into essential hardware units to develop a wide range of solid-state quantum technologies. For such applications, the long coherence time of NV centers is crucial. Numerous previous studies identified that the NV’s decoherence is often governed by the magnetic noise produced by the ¹³C nuclear spin bath and the nitrogen (P1) electron spin bath in a diamond. While the ¹³C-induced decoherence has been well understood, understanding of the P1-driven decoherence is still incomplete. In this study, we aim at the systematic theoretical investigation on the P1-driven decoherence of NV ensembles with varying P1 concentrations from 1ppm to 100ppm. We employ a cluster correlation expansion method. We discuss our results in comparison with recently published experimental data [1,2] and previous theoretical results [3,4]. Our results provide not only a microscopic understanding of the NV decoherence but also useful information to optimize the NV’s performance in various quantum applications such as NV-based magnetometry and NV-based quantum registers.

[1] E. Bauch et al., arXiv:1904.08763 (2019).
[2] V. Stepanov et al., PRB 94, 024421 (2016).
[3] Z. Wang et al., PRB 87, 115122 (2013).
[4] R. Hanson et al., Science 320, 352 (2008).