Experimental Optical Properties of Single Nitrogen Vacancy Centers in Silicon Carbide at Room Temperature

Robust single spin color centers in solid state systems with telecom wavelength emission are vital to quantum photonics and quantum networks. The nitrogen vacancy (NV) centers in silicon carbide (SiC) have become promising platforms for those applications. However, little is known about the detailed optical properties of the NV centers. In this paper, we investigate the photophysics of the single NV centers in 4H-SiC. The results demonstrate that the NV centers comprise three energy-level electronic structures. Particularly, for c-axis NV centers, both the excitation and the emission polarization degrees are larger than 90%. Photon purity and photostability of the single NV centers are maintained at an elevated temperature up to 400 K. These experiments constitute an important step toward using the NV centers in SiC with respect to quantum photonics.