Single-photon emitters in two-dimensional hexagonal boron nitride: properties, preparations, and applications

Single-photon emitters (SPEs) are key to quantum computation and quantum communication, which have been demonstrated in various two-dimensional (2D) materials. In particular, atomic defects in hexagonal boron nitride (hBN) exhibit the characteristics of a typical SPEs at room temperature, drawing great interest due to their potentials in quantum information and photonic applications. This paper reviews the synthetic methods to effectively obtain hBN thin films and deterministically fabricate color centers in 2D hBN. We further introduce their fundamental applications in several fields, such as coupling of surface plasmon to nanowires for quantum integrated circuits and nanoscale sensing. At last, we also discuss the challenges in this field and prospect their future applications.