Beryllium-Vacancy Color Centers in Diamonds: a Candidate Quantum Spin Sensor

Diamond color centers represent distinctive solid-state spin systems with unique spintronic and optical properties, making them promising candidates for applications in nanoscale quantum sensors, single-photon sources, and quantum information. In this study, density functional theory is employed to investigate the potential of the beryllium-vacancy (BeV) color center in diamonds, focusing on its spintronic and optical properties. The formation energy of BeV in different charge states suggests that BeV ²⁻ , BeV ⁻ , BeV ⁰ can form in diamond. The geometry optimization of these structures reveals that all possess C _3v symmetry. However, the calculations of electron spin occupation shows that only BeV ²⁻ possesses a state spin-triplet ground state, which is located deeply inside the bandgap of pristine diamond lattice. The optical transitions and spin flipping mechanisms of BeV ²⁻ are simulatively studied, revealing a prominent zero-phonon line (ZPL) at 582 nm, well within the visible light range. The effects of electron donors on the ZPL have also been explored as a confirmation in a doped system. These calculations demonstrate that BeV ²⁻ is a potential candidate for color center. This work may pave the way for future experimental investigations into the identification and characterization of the BeV center, as well as its potential applications in alternative nanoscale quantum sensors.