Fig. 1: Multiple optically addressable spin defects in hBN.
From: Multi-species optically addressable spin defects in a van der Waals material
a Schematic representation of two co-existing species of spin defects in hBN: the boron vacancy defect (\({V}_{{{\rm{B}}}}^{-}\), orange arrows) and a carbon-related defect (referred to as C?, purple arrows). An example candidate for C? is shown, namely the C2CN defect. b Photoluminescence (PL) spectra of hBN powder as received (dotted line) and after electron irradiation (solid line), under λ = 532 nm laser excitation. The shaded areas indicate the main emission band of C? (present in the as-received powder) and \({V}_{{{\rm{B}}}}^{-}\) (created by irradiation). c Optically detected magnetic resonance (ODMR) spectra of the \({V}_{{{\rm{B}}}}^{-}\) defects (PL band 750–1000 nm) in hBN powder at B0 = 0 (grey line) and B0 = 30 mT (blue). d Energy level diagram of the \({V}_{{{\rm{B}}}}^{-}\) spin triplet. The spin eigenstates are denoted as \(\left\vert 0,\pm \right\rangle\) in the general case of an arbitrarily oriented magnetic field. The graph shows the calculated spin resonance frequencies fr as a function of B0 for a range of field orientations. e ODMR spectra of the C? defects (PL band 550-700 nm) in the same hBN powder as in (c), at different field strengths B0 from 30 mT to 150 mT (left to right). f Energy level diagram of the C? effective spin doublet. The graph shows the spin resonance frequency fr inferred from (e) as a function of B0 (dots). The solid line is a linear fit, indicating a g-factor of 2.0(1).
