Anti-bunching behavior of photons and strain determination in boron-implanted single-crystal diamond using irradiation induced nitrogen-vacancies

Abstract

The work reports on irradiation-induced negatively-charged nitrogen-vacancy (${\mathrm{NV}}^{-}$) centres generation in single-crystal diamonds through boron ion-implantation (energy 130 keV), followed by subsequent annealing. Ion-implantation generates significant lattice defects, such as vacancies, which bind to substitutional nitrogen atoms to form ${\mathrm{NV}}^{-}$ centres during post-irradiation annealing process. The irradiation-induced ${\mathrm{NV}}^{-}$ centres were employed to determine the local strain and study the anti-bunching behavior of photons emitted from it. Single photon emission measurements exhibit the anti-bunching behavior of photons due to the presence of two- and three-color centres in the sample irradiated at fluence 1⨯10¹⁴ ions/cm². However, samples irradiated at fluences (5⨯10¹⁴ and 1⨯10¹⁵ ions/cm²) depict the presence of three- and four-color centres. At the same time, irradiation induces strain in the crystal, which affects the energy level of ${\mathrm{NV}}^{-}$ centres. The ${\mathrm{NV}}^{-}$ spin states have been probed by optically detected magnetic resonance (ODMR), demonstrate the increase of local strain with rise in irradiation fluence. The resulting strain caused by irradiation is dominated by transverse strain compared to axial strain along the ${\mathrm{NV}}^{-}$ centre. The ODMR results are consistent with strain estimated from Raman and X-ray diffraction analysis of irradiated diamond samples. Our results open the route for potential applications of irradiation-induced ${\mathrm{NV}}^{-}$ centres in stain imaging, sensing, and quantum information processing devices.