First-principles theory of Cr-vacancy in BaZrO₃ as a solid-state qubit candidate

Recently, remarkable advances have been made in the development of solid-state quantum bits (qubits), which are the basic hardware units of quantum information processing. One of the leading solid-state qubit platforms is the nitrogen-vacancy (NV) center in diamond. Furthermore, a significant interest has been emerging in the literature to develop such defect-based qubits in diverse wide-gap semiconductors for broadening the scope of the solid-state quantum information. In this study, we explore a Cr-O vacancy complex in BaZrO₃ as a potential solid-state qubit candidate. We use first-principles density functional theory to examine the stability and the electronic and spin properties of the Cr-O vacancy pair in BaZrO₃. To investigate the stability of the defect in various charge states, we calculate the defect formation energy of Cr-vacancy in BaZrO₃. In addition, we use HSE06 hybrid functionals to accurately calculate the defect level diagram and the zero-phonon line of the Cr-O vacancy. In the poster, we also discuss the recent progress and challenges in computational design of new defect qubits in complex wide-gap materials.