»ã±¨±êÌâ (Title)£ºQuantum Color Centers in Few-Layer h-BN£¨ÉÙ²ãÁù·½µª»¯Åðh-BNÖеÄÁ¿×ÓÉ«ÐÄ£©

»ã±¨ÈË (Speaker)£º¼Ö·«ºÀ ÌØƸ¸±½ÌÊÚ£¨º¼Öݵç×ӿƼ¼´óѧ£©

»ã±¨¹¦·ò (Time)£º2023Äê12ÔÂ18ÈÕ(ÖÜÒ») 10:30

»ã±¨µØÖ· (Place)£ºÐ£±¾²¿ E106

Ô¼ÇëÈË (Inviter)£ºÈÎΰ ½ÌÊÚ

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ÌáÒª (Abstract)£º

Color centers with deep-level states in the wide-gap h-BN monolayer have great potential applications in quantum devices. We have performed first-principles calculations to investigate the coupling effects between structural, electronic, and vibrational properties of the CBVN and NBVN color centers in the h-BN monolayer. Their ground-state structure can be planar or out-of-plane distorted, depending on the occupations of defect states. This talk will focus on the impact of the out-of-plane displacement and revealed its origin by analyzing the chemical bonding features of the defect states and the pseudo Jahn-Teller (PJT) effect of electron-phonon coupling. Although the out-of-plane displacements do not significantly change the vibrational set, these distinct quasi-local phonons suggested by local vibrational analysis can still be used as fingerprints to support experimental studies to identify specific point defects. We then extend our interest to the few-layer h-BN where the layered structure itself introduces a complex set of combined effects, including quantum confinement effects of different layer thicknesses, local symmetries of specific stacking orders, and varying electron-phonon coupling due to certain local displacements. These findings will deepen the understanding of quantum color center systems using few-layer van der Waals materials.