Li Song, Gali Adam
Wigner Research Centre for Physics, Post Office Box 49, H-1525Budapest, Hungary.
Department of Atomic Physics, Institute of Physics, Budapest University of Technology and Economics, Műegyetem rakpart 3, H-1111Budapest, Hungary.
J Phys Chem Lett. 2022 Oct 20;13(41):9544-9551. doi: 10.1021/acs.jpclett.2c02687. Epub 2022 Oct 6.
Paramagnetic fluorescent defects in two-dimensional hexagonal boron nitride (hBN) are promising building blocks for quantum information processing. Although numerous defect-related single-photon sources and a few quantum bits have been found, except for the boron vacancy, their identification is still elusive. Here, we demonstrate that the comparison of experimental and first-principles simulated electron paramagnetic resonance (EPR) spectra is a powerful tool for defect identification in hBN, and first-principles modeling is inevitable in this process as a result of the dense nuclear spin environment of hBN. In particular, a recently observed EPR center is associated with the negatively charged oxygen vacancy complex by means of the many-body perturbation theory method on top of hybrid density functional calculations. To our surprise, the negatively charged oxygen vacancy complex produces a coherent emission around 2 eV with a well-reproducing previously recorded photoluminescence spectrum of some quantum emitters, according to our calculations.
二维六方氮化硼（hBN）中的顺磁荧光缺陷是量子信息处理中很有前景的构建模块。尽管已经发现了许多与缺陷相关的单光子源和一些量子比特，但除了硼空位之外，它们的识别仍然难以捉摸。在这里，我们证明实验和第一性原理模拟的电子顺磁共振（EPR）光谱的比较是hBN中缺陷识别的有力工具，由于hBN密集的核自旋环境，第一性原理建模在这个过程中是必不可少的。特别是，通过在混合密度泛函计算之上的多体微扰理论方法，最近观察到的一个EPR中心与带负电的氧空位复合体相关。令我们惊讶的是，根据我们的计算，带负电的氧空位复合体在2 eV左右产生相干发射，与之前记录的一些量子发射体的光致发光光谱很好地吻合。
