Előadó: Ghafari Cherati, Nima (Wigner FK SZFI) PhD házivédés
Előadásának címe: Investigation of point defects in diamond by means of ab initio simulations
Dátum: 2026. június 18. csütörtök , 14 óra
Helyszín: 1-es épület tanácsterem
Összefoglaló:
Point defects in diamond are promising building blocks for quantum technologies because they can host localized electronic states with useful optical and spin properties. In my work, first-principles calculations based on density functional theory were used to investigate selected defect complexes in diamond and to connect their atomic structures with experimentally measurable properties, including formation energies, charge-state stability, electronic levels, zero-field splitting, hyperfine interactions, vibrational signatures, and optical transitions.
Three classes of defects were studied. Oxygen–vacancy complexes were examined as possible microscopic models of the ST1 color center, but their calculated triplet ground states rule them out as candidates for ST1, while identifying oxygen-vacancy complexes as potentially interesting paramagnetic or optically active defects. Carbon self-interstitial aggregates were investigated as candidates for intrinsic optical centers such as TR12 and 3H, revealing systematic trends in their stability, bonding, vibrational properties, and optical activity. Sulfur-related defects were analyzed to clarify their role in enhancing NV-center creation, showing that vacancy charging and hydrogen trapping can suppress competing defect formation pathways. These results provide atomistic insight into the identification and engineering of diamond defects for quantum-technology applications.
2026. június 18. csütörtök, 14.00
Wigner FK SZFI, 1. ép. 1. em. nagy előadóterem
