Decoherence of nitrogen-vacancy spin ensembles in diamond in the nitrogen electron-nuclear spin bath*

Nitrogen-vacancy (NV) centers in diamond have been developed into essential hardware units to develop a wide range of solid-state quantum technologies [1]. 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, the understanding of the P1-driven decoherence is still incomplete. In this study, we aim at a systematic investigation on the P1-driven decoherence of NV ensembles with varying P1 concentrations from 1ppm to 100ppm by combining cluster correlation expansion theory and density functional theory. We find an excellent agreement between our theoretical results and previous experimental results [2,3]. We also discuss the microscopic mechanism of the P1-induced decoherence of the diamond NV center in detail. Our results provide a key reference, which can be employed to optimize the NV’s performance in various quantum applications such as NV-based magnetometry and NV-based quantum sensors.

[1] G. Wolfowicz et al., Nat. Rev. Meter. 6, 869 (2021).

[2] E. Bauch et al., PRB 102, 134210 (2020).

[3] V. Stepanov et al., PRB 94, 024421 (2016).