Haykal A, Tanos R, Minotto N, Durand A, Fabre F, Li J, Edgar J H, Ivády V, Gali A, Michel T, Dréau A, Gil B, Cassabois G, Jacques V
Laboratoire Charles Coulomb, Université de Montpellier and CNRS, Montpellier, France.
Tim Taylor Department of Chemical Engineering, Kansas State University, Manhattan, KS USA.
Nat Commun. 2022 Jul 27;13(1):4347. doi: 10.1038/s41467-022-31743-0.
Spin defects in hexagonal boron nitride (hBN) are promising quantum systems for the design of flexible two-dimensional quantum sensing platforms. Here we rely on hBN crystals isotopically enriched with either B or B to investigate the isotope-dependent properties of a spin defect featuring a broadband photoluminescence signal in the near infrared. By analyzing the hyperfine structure of the spin defect while changing the boron isotope, we first confirm that it corresponds to the negatively charged boron-vacancy center (). We then show that its spin coherence properties are slightly improved in B-enriched samples. This is supported by numerical simulations employing cluster correlation expansion methods, which reveal the importance of the hyperfine Fermi contact term for calculating the coherence time of point defects in hBN. Using cross-relaxation spectroscopy, we finally identify dark electron spin impurities as an additional source of decoherence. This work provides new insights into the properties of spin defects, which are valuable for the future development of hBN-based quantum sensing foils.
六方氮化硼（hBN）中的自旋缺陷是用于设计柔性二维量子传感平台的有前途的量子系统。在这里，我们依靠同位素富集有(^{10}B)或(^{11}B)的hBN晶体来研究具有近红外宽带光致发光信号的自旋缺陷的同位素依赖性特性。通过在改变硼同位素的同时分析自旋缺陷的超精细结构，我们首先确认它对应于带负电荷的硼空位中心（(B_v^-)）。然后我们表明，在富含(^{10}B)的样品中其自旋相干特性略有改善。这得到了采用团簇相关展开方法的数值模拟的支持，该模拟揭示了超精细费米接触项对于计算hBN中点缺陷的相干时间的重要性。使用交叉弛豫光谱，我们最终确定暗电子自旋杂质是退相干的另一个来源。这项工作为自旋缺陷的特性提供了新的见解，这对于基于hBN的量子传感箔的未来发展具有重要价值。
