Localized electric-field induced defects in hexagonal boron nitride for site-controlled quantum emitters

Controlling the sites of artificial defects in two-dimensional materials is a critical challenge in color center applications such as quantum emission, quantum communication, and quantum cryptography. Recently, the color center of hexagonal boron nitride (h-BN) has a wide range and brightness of emission light at room temperature, chemical and thermal robustness leading to more and more attention recently. We here investigate color centers in h-BN created by applying a tip-induced electric field, and the tip position controls the sites of the color centers. Due to prevent the emission of various organic residues from typical transferring processes coupling into color center emission, here we directly create defects on the h-BN grown by using plasma-assisted molecular beam epitaxy (PA-MBE) on SiC substrate with single crystalline quality and large area up to wafer scale. A variety of intensity, energy, and position control in h-BN defects are observed in scanning microscopies with morphology and luminescence visibilities. And the quantum phenomenon is characterized by pronounced single-photon antibunching in a zero-delay time. Because of the controllability of the defect position, the emission properties are also highly controllable in our h-BN systems and, thus, can potentially be tuned for future quantum optical applications.