Quantum noise spectroscopy of nanoscale charge defects in silicon carbide at room temperature.

The nanoscale charge environment critically influences the performance of semiconductor devices, yet traditional characterization techniques usually lack the spatial resolution to resolve nanoscale charge heterogeneity and identify microscopic noise sources. Here, we address this critical gap using individual PL5 color centers in commercial silicon carbide as room-temperature, broadband (near-dc to gigahertz) quantum spectrometers. We report real-time, nanoscale observation of single-charge tunneling dynamics at room temperature in 4H-SiC by monitoring the random telegraph noise using optically detected magnetic resonance. This capability enables an electrical noise imaging technique that shows distinct noise variations on different wafers. Using dynamical decoupling and [Formula: see text] relaxation spectroscopy, we observe correlations of noise spectral density across frequency bands and obtain the nanoscale electron paramagnetic resonance fingerprint of spin defects in silicon carbide. Ultimately, through surface chemical engineering, we identify the native oxide layer as the main source of resolved electromagnetic fluctuations. This work establishes a versatile atomic-scale metrology platform bridging quantum sensing and semiconductor engineering, offering critical insights for optimizing third-generation semiconductor interfaces and advancing solid-state quantum technologies.