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arXiv · 2606.14545

First-principles calculations of internal conversion processes in spin defects

Stefano Paolo Villani·Yu Jin·Giulia Galli
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Abstract

Optically active spin defects are foundational for quantum technologies, yet common approximations underestimate their internal conversion (IC) rates by orders of magnitude. We propose a broad, predictive framework to compute IC rates that incorporates multi-configurational effects via many-body wavefunctions in TDDFT, and includes all-phonon-mode contributions via analytical non-adiabatic couplings. Our approach resolves discrepancies with experiment, achieving quantitative agreement for the NV$^-$ center in diamond, and identifying a previously overlooked non-radiative channel in the divacancy triplet lifetime in SiC.

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Stefano Paolo Villani, Yu Jin, Giulia Galli. 2026-06-12. First-principles calculations of internal conversion processes in spin defects. https://arxiv.org/abs/2606.14545

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