Beryllium oxide as a host for quantum defects

The large bandgap of BeO, which exceeds 10 eV, makes BeO a promising host for quantum defects. We have performed a comprehensive first-principles study of the native point defects in BeO, using density functional theory with the hybrid functional of Heyd, Scuseria, and Ernzerhof (HSE). We investigated various properties of BeO native defects, including the atomic geometries, orbital structure, spin properties, and optical properties. The Fermi level of pure BeO is pinned near midgap based on charge neutrality of the native defects. We found that the beryllium and oxygen vacancies are the most stable native defects in BeO, while other native defects like interstitials or antisites are high in formation energy. Based on our survey, we identified defects with electron states well separated from the band edges that are potential quantum defects. We found that the neutral beryllium vacancy, which has similarities to the NV center in diamond, may have desirable optical sensing applications due to its large electron-phonon coupling.