Quantum Optics with Defects in Hexagonal Boron Nitride
Abstract: Photonics technology has reached a stage in which complex functional devices for the generation and detection of light signals can be routinely produced. Especially, the search for novel computation and communication schemes has created applications in which the manipulation and detection of extremely weak optical signals at single photon level are crucial. Among several systems, quantum emitters in atomically thin 2D based materials, i.e., transition metal di-chalcogenides and defects in hexagonal boron nitride (hBN), have recently attracted a great interest as potentially bright and stable solid-state single-photon sources.
In this talk, I will present our recent activities on optical properties of hBN. Because of its large bandgap (5.995 eV), hBN is known to be a good insulator, which also becomes an ideal candidate for exploring optically active defects with energies from UV to NIR. Isolated defect centers in hBN are especially important to develop on-chip room temperature single photon sources. To gain insight about the optical properties, we study the temperature dependent properties of zero-phonon line (ZPL) emission from isolated defect centers. The lineshape of the ZPL and its phonon sidebands in the emission spectrum show chracteristic features governed by the phonon density of states of the host hBN, which has contributions from both acoustic and optical phonons, and a phonon gap. Finally, I will present recent results on efficient energy transfer between a single defect in hBN and graphene at single photon level.