Curvature-driven atomic localization and dipole alignment of quantum emitters in h-BN

Hexagonal boron nitride (h-BN) has recently emerged as a promising materials platform for developing various solid-state quantum technologies. In particular, a number of color centers in h-BN have been found to be stable and bright single-photon-emitters (SPEs) operating at room temperature, which are crucial elements for quantum optical applications. In this talk, we combine first-principles theory and experiment to investigate the intimate relation between curvature in h-BN and atomic localization of SPEs. We use density functional theory to calculate the energetically stable configuration of various defect models of the SPEs in a buckled h-BN plane with different curvatures. We show that the vacancy-derived point defects in h-BN prefer to form in the highest-curvature area of the buckle and we find that the high curvature induces a dimer reconstruction for the atoms surrounding vacancy. Our result provides not only a microscopic understanding on the recent experimental observations of the SPEs being located in h-BN buckles but also strongly suggests that the atomic origin of the SPEs may be vacancy-derived. We also discuss several key features of the SPEs formed on h-BN buckle such as dipole orientation, which would be helpful to design future experiments of the SPEs in h-BN.