Quantifying the creation of negatively charged boron vacancies in He-ion irradiated hexagonal boron nitride
Amedeo Carbone, Ilia D. Breev, Johannes Figueiredo, Silvan Kretschmer, Leonard Geilen, Amine Ben Mhenni, Johannes Arceri, Arkady V. Krasheninnikov, Martijn Wubs… 展开作者
Amedeo Carbone, Ilia D. Breev, Johannes Figueiredo, Silvan Kretschmer, Leonard Geilen, Amine Ben Mhenni, Johannes Arceri, Arkady V. Krasheninnikov, Martijn Wubs, Alexander W. Holleitner, Alexander Huck, Christoph Kastl, Nicolas Stenger
Hexagonal boron nitride (hBN) hosts luminescent defects possessing spin qualities compatible with quantum sensing protocols at room temperature. Vacancies, in particular, are readily obtained via exposure to high-energy ion beams. While the defect creation mechanism via such irradiation is well understood, the occurrence rate of optically active negatively charged vacancies ($V_B^-$) is an open question. In this work, we exploit focused helium ions to systematically generate optically active vacancy defects in hBN flakes at varying density. By comparing the density-dependent spin splitting measured by magnetic resonance to calculations based on a microscopic charge model, in which we introduce a correction term due to a constant background charge, we are able to quantify the number of $V_B^-$ defects generated by the ion irradiation. We find a lower bound for the fraction (0.2%) of all vacancies in the optically active, negatively charged state. Our results provide a protocol for measuring the generation efficiency of $V_B^-$, which is necessary for understanding and optimizing luminescent centers in hBN.
Non-radiative energy transfer between boron vacancies in hexagonal boron nitride and other 2D materials
Université de Toulouse, INSA-CNRS-UPS（图卢兹大学，INSA-CNRS-UPS）；Ioffe Institute, Russian Academy of Sciences（约费研究所，俄罗斯科学院）；Laboratoire Charles Coulomb, Université de Montpellier and CNRS（夏尔·库隆实验室，蒙彼利埃大学和法国国家科学研究中心）；Institut Universitaire de France（法兰西学院）
Impact of Monoatomic Vacancies in 2D Materials on the Performance of Magnetic Tunnel Junction Devices: Insights from Configurations and Interface Interactions
Competition between vacancy creation and filling in defect-engineering of hBN
University of Vienna（维也纳大学）；Univ. Paris-Saclay, CNRS, Laboratoire de Physique des Solides（巴黎萨克雷大学，法国国家科学研究中心，固体物理实验室）；Institute for Microelectronics, TU Wien（TU维也纳微电子研究所）
Interstitial-mediated dislocation climb and the weakening of particle-reinforced alloys under irradiation
位错可以通过吸收（或发射）点缺陷（空位和自填隙原子（SIAs））爬出其滑移面。与保守的滑翔运动相反，爬升依赖于点缺陷的热扩散，因此在更长的时间尺度上运行，导致某些形式的蠕变。虽然平衡点缺陷浓度允许位错爬升以减轻非滑移应力，但点缺陷过饱和也会导致渗透力，即使在没有外部应力的情况下也会驱动位错运动。自填隙原子通常具有比空位高得多的形成能，因此它们对爬升的贡献通常被忽略。然而，在辐照条件下，这两种类型的缺陷以相等的数量非热地产生。在这封信中，我们使用简单的热力学参数来表明，在辐照材料中的贡献不可忽略，并且它们对位错引起的渗透力比空位引起的渗透力大许多个数量级。这就解释了为什么{ \it in situ}透射电子显微镜辐照观察到的棱柱形位错环更多的是间隙型而不是空位型。使用离散位错动力学模拟，我们调查的影响，位错障碍物的相互作用，并发现在许多数量级的脱钉时间减少。这对辐照下颗粒增强合金的强度具有重要影响。
Single photon emitters in hBN: Limitations of atomic resolution imaging and potential sources of error
TU Vienna（维也纳工业大学）；University of Vienna, Faculty of Physics（维也纳大学物理学院）；University Paris-Saclay, CNRS, Laboratoire de Physique des Solides（巴黎萨克雷大学，法国国家科学研究中心，固体物理实验室）
