Stark shift from quantum defects in hexagonal boron nitride

Color centers in hexagonal boron nitride have emerged as promising candidates for quantum information applications due to their efficient and bright single-photon emission. Despite the challenges in directly characterizing these emitters, the interaction of defects with external fields, such as the Stark shift, offers valuable insights into their local geometric configurations. In this study, we focus on clarifying the possible origin of the distinct Stark shift characteristics observed experimentally, particularly in the emission energy around 2 eV. We find that the local symmetry of the defects plays a crucial role in determining the nature of the Stark shift, which can be either linear or quadratic. Additionally, the local dielectric environment significantly influences the Stark shift response. Our calculations not only enhance the understanding of the microstructure of these hitherto unknown emitters, but they also pave the way for their more effective utilization as single-photon sources and qubits in quantum technologies.