First Principles Investigations of NV-like centers in oxides

Recent predictions¹ suggest that oxides, such as MgO, may possess long coherence times and thus could serve as promising hosts for point defects for quantum applications. This points at the exciting prospect of going beyond the NV- center in diamond to design defects and hosts that are compatible with present telecommunication and manufacturing infrastructure. However, specific, promising defects are yet to be identified in most oxides. Leveraging a high-throughput first principles workflow², we predict that MgO can host NV-like centers with favorable electronic and optical properties. Using time-dependent density functional theory³, we find that these defects have a stable spin triplet state, and we report their absorption, emission, and zero-phonon lines. The defects identified here have a large relaxation in the excited state via the pseudo-Jahn Teller effect due to significant vibronic interaction between excited states. We expect such substantial electron-lattice interaction to be a general feature of oxide hosts. We also discuss the role of strain in tuning the excited state potential energy surface, thereby providing crucial insight into engineering the electronic and optical properties of point defects in a class of promising oxide hosts for quantum applications.

Work funded by the Midwest Integrated Center for Computational Materials (MICCoM) which is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences (DOE-BES).

References:

¹Shun Kanai et al. PNAS 119.15 (2022): e2121808119.

²Joel Davidsson et al. Comput. Phys. Commun. 269 (2021): 108091.

³Yu Jin et al. npj Comput. Mater. 8.1 (2022): 238.