Nothing is perfect: defects in hexagonal boron nitride – NOTISPERF

Point defects in crystals occur when an atom is missing or is in an irregular position. After an initial skepticism, they spiked interest because of their possible applications as qubits in quantum computers. A strong and stable photoluminescence at room temperature (RT) and a single photon emission are the needed requirements. Point defects in hexagonal Boron Nitride(hBN) have been experimentally identified as RT stable single photon sources. In the photoluminescence spectrum of hBN there are different emission lines at transition energies ranging over the visible and the UV spectrum, and well-resolved phonon replica at lower energies. Whereas a considerable effort has been made so far and several color centers candidate have already been suggested, their exact nature remains uncertain. This project aims to solve some controversies related to the interpretation of defect related emission lines, with a special care for the study of the local vibrations at the origin of phonon replica.