3. Physikalisches Institut, Universität Stuttgart, Stuttgart, Germany.
Max Planck Institute for Solid State Research, Stuttgart, Germany.
Nat Mater. 2021 Aug;20(8):1079-1084. doi: 10.1038/s41563-021-00979-4. Epub 2021 May 6.
A plethora of single-photon emitters have been identified in the atomic layers of two-dimensional van der Waals materials. Here, we report on a set of isolated optical emitters embedded in hexagonal boron nitride that exhibit optically detected magnetic resonance. The defect spins show an isotropic g-factor of ~2 and zero-field splitting below 10 MHz. The photokinetics of one type of defect is compatible with ground-state electron-spin paramagnetism. The narrow and inhomogeneously broadened magnetic resonance spectrum differs significantly from the known spectra of in-plane defects. We determined a hyperfine coupling of ~10 MHz. Its angular dependence indicates an unpaired, out-of-plane delocalized π-orbital electron, probably originating from substitutional impurity atoms. We extracted spin-lattice relaxation times T of 13-17 μs with estimated spin coherence times T of less than 1 μs. Our results provide further insight into the structure, composition and dynamics of single optically active spin defects in hexagonal boron nitride.
大量的单光子发射器已经在二维范德瓦尔斯材料的原子层中被识别出来。在这里，我们报告了一组嵌入在六方氮化硼中的孤立光学发射器，它们表现出光探测磁共振。缺陷自旋表现出约为 2 的各向同性 g 因子和低于 10 MHz 的零场分裂。一种类型的缺陷的光动力学与基态电子自旋顺磁性兼容。窄且不均匀展宽的磁共振谱与已知的面内缺陷谱有显著差异。我们确定了约 10 MHz 的超精细耦合。其角依赖性表明存在非配对的、面外离域的π轨道电子，可能源自取代杂质原子。我们提取了自旋晶格弛豫时间 T 为 13-17 μs，估计自旋相干时间 T 小于 1 μs。我们的结果为六方氮化硼中单个光学活性自旋缺陷的结构、组成和动力学提供了进一步的见解。
