Identification of defects responsible for optically detected magnetic resonance in hexagonal boron nitride

VNCB defect as source of single photon emission from hexagonal boron nitride

“…In a recent experimental study, the observation of an increased density of emitters with ZPL close to 2 eV following controlled incorporation of carbon into hBN is reported [17]. The work tentatively assigns the emission to a V N C B defect based upon previous theoretical reports [4,10,13,15,16,18] none of which, however, provide key spectroscopic observables in agreement with the new experiments.…”

“…Their exploitation, however, depends on a thorough understanding of the chemical nature of the colour centres in hBN and the ability to control and tune their structural arrangements and spectroscopic properties. While various colour centres have been proposed as potential sources of SPEs in hBN [9][10][11][12], only a few defects have been conclusively identified [10,13,14]. Many attempts have been made to predict the exact nature of the defect causing emission in the visible part of the spectrum, i.e.…”

“…Many attempts have been made to predict the exact nature of the defect causing emission in the visible part of the spectrum, i.e. in the vicinity of 2 eV [4,[9][10][11]13,15,16]. However, no conclusive evidence for the nature of the defect in the form of theoretically predicted properties matching the experimental data, has so far been presented [10].…”

First-Principles Identification of Single Photon Emitters Based on Carbon Clusters in Hexagonal Boron Nitride

“…Despite extensive theoretical attempts to identify the atomic structure associated with SPE defects found in h-BN [14,[21][22][23][24][25][26][27], up to now few defect configurations have been proposed. The theoretical work has mostly relied on density functional theory (DFT) under the assumption that it can provide transition energies accurate enough to estimate the zero-phonon line (ZPL) and compare it to arXiv:2007.15990v1 [cond-mat.mtrl-sci] 31 Jul 2020 experimentally measured values [28].…”

DMRG on top of plane-wave Kohn-Sham orbitals: case study of defected boron nitride

“…In particular, additionally to favourable optical properties, point defects in hBN with spin could possibly implement quantum bits controllable by optically detected magnetic resonance which signal has been recently reported at room temperature. 8,9 The standard theoretical approach to study such defects is based on first-principles methods, [10][11][12][13][14][15][16][17][18][19][20][21][22] in particular on the Kohn-Sham density functional theory (KS-DFT), 23 which established itself as one of the most prevalent numerical methods both in material science and theoretical chemistry offering balanced compromise between accuracy and computational costs. Despite its immense success attained in the field of weakly correlated systems, it is challenged to describe accurately quasi-degenerate electronic structures exhibiting strong correlations.…”