Abstract

Nitrogen-vacancy (NV) centers in diamond are leading solid-state qubits and nanoscale sensors, yet their spin coherence degrades in the presence of surfaces, interfaces, and extended defects. In this talk, I will discuss how these structural and electronic imperfections generate magnetic, electric, and strain noise that degrade NV coherence and how such interactions can also be harnessed as quantum resources. Using density functional theory and cluster correlation expansion techniques, we (in collaboration with Giulia Galli) developed a framework that connects measured noise spectra to the dynamics of surface and bulk defects. We show that incorporating dissipative and hopping processes of surface dark spins accurately captures surface-induced decoherence, allowing us to pinpoint individual decoherence channels and identify geometrically induced coherence sweet spots that enhance NV stability and coherence. Together, these insights reveal the microscopic origins of decoherence at key boundaries and provide design rules for NV-based quantum sensing, spin-photon interfaces, and scalable diamond quantum technologies.