Lifetime-Limited Line Width of Silicon Vacancy Centers in Nanodiamonds at 9 K

Silicon vacancy (SiV) centers in nanodiamonds have received significant attention because of their superior optical properties. Consequently, they are suitable for integration in nanophotonic devices to perform quantum information processing. Despite their excellent characteristics, their practical application is limited because to exhibit a lifetime-limited line width from SiV centers in nanodiamonds, the samples need to be cooled down to 2 K. Herein, we observed the lifetime-limited line width of the SiV centers in high-strain nanodiamonds at 7.1 K. Moreover, the analysis of the PLE line width variation with temperature suggested that the homogeneous line width reached a lifetime-limited line width even at 9.0 K. The results indicate that such SiV centers can act as indistinguishable single photon sources operating at easily accessible temperatures. This is crucial in quantum photonic technologies based on SiV centers in nanodiamonds.