Regular Article

Optimizing the density of nitrogen implantation for generating high-density NV center ensembles for quantum sensing

¹ Key Laboratory of Strongly-Coupled Matter Physics, Chinese Academy of Sciences, and Hefei National Laboratory for Physical Science at Microscale, Hefei, Anhui 230026, P.R. China
² Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, P.R. China

^a e-mail: gzwang@ustc.edu.cn

Received: 28 January 2019
Revised: 20 June 2019
Published online: 12 September 2019

Abstract

We prepared four NV center ensembles with different nitrogen atom doses at the same diamond by ion implantation. The densities of NV centers in the samples were analyzed using their fluorescence intensities and PL spectra, which increases with the implantation dose and reaches a maximal value at a dose of 10¹⁴ cm⁻², corresponding to the nitrogen density of 3.1 × 10¹⁹ cm⁻³. Ramsey measurement showed that no significant difference was found in the dephasing time between the four NV⁻ center ensembles. The results suggest that the quantum sensor utilizing NV⁻ ensemble centers can achieve its best sensitivity when the density of nitrogen atoms in diamond is about 3.1 × 10¹⁹ cm⁻³.