Silicon carbide nanophotonics with integrated NV centers below 2 K

Silicon carbide color centers are promising candidates for quantum computing, sensing, and networking devices due to their long coherence times and near-telecom band emission. We demonstrate the first integration of silicon carbide NV centers into nanophotonic devices, using a novel wafer-scale angle-etching technique. We fabricate nanopillars showing enhanced collection from NV ensembles, as well as freestanding waveguides and resonator structures showing no distortion of color center optical properties. These measurements are performed in an innovative optical cryostat which achieves sub-2K temperatures, allowing for the integration of superconducting nanowire single photon detectors directly in the sample chamber. Using these detectors, we measure the optical lifetime of ensembles in nanopillars. By spectrally selecting the ZPLs of the different orientations, we further measure the lifetime of one basal ($hk$) and one axial ($kk$) orientation of the NV.