Neutral oxygen-vacancy defect in cubic boron nitride: A plausible qubit candidate

Experimental feasibility of potential quantum sensing and computing applications based on the oxygen-vacancy defect (V_BO_N center) in cubic boron nitride (c-BN) is theoretically predicted by means of first-principles calculations. The proposed V_BO_N center consisting of a boron vacancy (V_B) and an adjacent substitutional oxygen (O_N) is a plausible qubit candidate, which is isoelectronic to the NV^- center in diamond. We found that the neutral paramagnetic V_BO_N center is spin-triplet and exists mainly in p-type c-BN. The results demonstrate that the zero-field splitting of the neutral V_BO_N center in the ground state falls within the microwave range and has a value of approximately 2980 MHz. Furthermore, the neutral V_BO_N center hyperfine interactions in the ground state are determined to be in the tens of MHz. It is anticipated that our results will pave the way for the neutral V_BO_N center acting as a scalable platform for implementing quantum information processing, sensing, and beyond.