Unraveling the electronic structure of silicon vacancy centers in 4H-SiC
Max-Planck Institut für Polymerforschung（马克斯·普朗克聚合物研究所）；Department of Physics / Centre for Material Science and Nanotechnology, University of Oslo（奥斯陆大学物理系/材料科学与纳米技术中心）；Department of Physics, Chemistry and Biology, Linköping University（林雪平大学物理、化学和生物学系）；Takasaki Institute for Advanced Quantum Science, National Institutes for Quantum Science and Technology: QST（量子科学技术研究机构高崎高级量子科学研究所）；Department of Materials Science, Tohoku University（东北大学材料科学系）；Wigner Research Centre for Physics, Hungarian Academy of Sciences（匈牙利科学院维格纳物理研究中心）；Department of Fundamental Research, Center for Physical Sciences and Technology (FTMC)（立陶宛维尔纽斯物理与技术中心基础研究部）
Ali Tayefeh Younesi, Minh Tuan Luu, Christopher Linderälv, Vytautas Žalandauskas, Marianne Etzelmüller Bathen, Nguyen Tien Son, Takeshi Ohshima, Gergő Thiering,… 展开作者
Ali Tayefeh Younesi, Minh Tuan Luu, Christopher Linderälv, Vytautas Žalandauskas, Marianne Etzelmüller Bathen, Nguyen Tien Son, Takeshi Ohshima, Gergő Thiering, Lukas Razinkovas, Ronald Ulbricht
Point defects in silicon carbide (SiC), particularly the negatively-charged silicon vacancy ($\mathrm{V_{Si}^{-}}$) in 4H-SiC, are leading candidates for scalable quantum technologies due to their favorable spin-optical properties and compatibility with industrial semiconductor fabrication processes. Comprehensive knowledge of a defect's electronic structure is essential for interpreting spin-optical dynamics and for the reliable design and optimization of defect-based quantum devices. Despite extensive study, our knowledge of the electronic structure of $\mathrm{V_{Si}^{-}}$\ is limited since key excited-state manifolds have remained inaccessible to conventional steady-state spectroscopy. In this study, transient absorption spectroscopy is utilized to probe non-equilibrium electronic transitions of $\mathrm{V_{Si}^{-}}$\ and to uncover previously unobserved excited states. The first direct observation of the elusive V2' quartet transition is presented, with its broad spectral signature attributed to nonadiabatic vibronic coupling. Within the spin-doublet manifold, which is central to optically detected magnetic resonance (ODMR) but has remained unresolved spectroscopically, multiple optical transitions are identified. The complete electronic level structure in the relevant energy range is elucidated by combining polarization-resolved spectroscopy, group-theoretical analysis, quantum embedding calculations and first-principles optical lineshape modeling. Collectively, these results provide a microscopic understanding of the $\mathrm{V_{Si}^{-}}$\ electronic structure. Our approach also establishes a general framework for resolving and understanding complex excited-state manifolds in wide-bandgap color centers.
Optically addressable silicon vacancy-related spin centers in rhombic silicon carbide with high breakdown characteristics and ENDOR evidence of their structure
Vibronic states and their effect on the temperature and strain dependence of silicon-vacancy qubits in 4H silicon carbide
碳化硅（SiC）中的硅空位量子比特由于其优异的光学和自旋特性而成为量子技术应用中的新兴工具。在本文中，我们探讨了温度和应变对这些性质的影响，重点是两个硅空位量子比特，V1和V2，在4 H SiC。我们应用超越Born-Oppenheimer近似的密度泛函理论来描述声子辅助下的电子激发态的温度依赖混合。我们得到了V1和V2中心的极化子能隙分别为5和22~meV，这导致了激发态的温度相关退相和零场分裂的显著差异，解释了最近的实验结果。我们还计算了晶体形变对这些发射体的零声子线的影响。我们的预测是这些量子比特对这些效应敏感的任何量子应用的重要组成部分。
All-optical dc nanotesla magnetometry using silicon vacancy fine structure in isotopically purified silicon carbide
我们揭示了同位素纯化的碳化硅（4 H- $^{28}$ SiC）中硅空位的精细结构，并在自旋哈密顿量中发现了额外的条款，起源于这个自旋3/2色心的三角锥对称性。这些条款引起额外的自旋跃迁，否则是禁止的，并导致在外部磁场的水平anticrossing。我们观察到一个急剧变化的光致发光强度在附近的这个水平的anticrossing，这可以用于一个纯粹的全光学传感的磁场。我们在室温下实现了$3 \times 10^{-7}$ mm $^{3}$的体积内87 nT Hz $^{-1/2}$的直流磁场灵敏度，并证明了这种非接触式方法在高达至少500 K的高温下是稳健的。由于我们的方法不需要应用射频场，因此可以扩展到更大的体积。对于3 mm $^{3}$的优化光捕获波导，投影噪声极限低于100 fT Hz $^{-1/2}$。
Towards Identifying the PL6 Center in SiC: From First-Principles Screening to Hyperfine Validation of Competing Defect Candidates
University of Science and Technology of China（中国科学技术大学）；CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China（中国科学院量子信息与量子物理前沿卓越中心，中国科学技术大学）；School of Biomedical Engineering and Suzhou Institute for Advanced Research, University of Science and Technology of China（中国科学技术大学生物医学工程与先进技术学院，苏州）；Institute of Quantum Sensing and School of Physics, Zhejiang University（浙江大学量子传感研究所和物理学院）；Hefei National Laboratory, University of Science and Technology of China（合肥国家实验室，中国科学技术大学）
Device contacts as spin-state selectors for silicon vacancies in 4H-SiC
University of Oslo（奥斯陆大学）；ETH Zürich（苏黎世联邦理工学院）；Paul Scherrer Institute（保罗谢尔研究所）；California Institute of Technology（加州理工学院）；NASA Jet Propulsion Laboratory（美国国家航空航天局喷气推进实验室）
Defect-Mediated Phase Engineering of 2D Ag at the Graphene/SiC Interface
The Pennsylvania State University（宾夕法尼亚州立大学）；Max-Planck-Institut für Festkörperforschung（马克斯·普朗克固体研究所）；National University of Singapore（新加坡国立大学）；University of Münster（明斯特大学）；Paul-Drude-Institut für Festkörperelektronik（保罗·德鲁德固体电子学研究所）；University of Pittsburgh（匹兹堡大学）；Juniata College（朱尼阿塔学院）
Decoupling Many-Body Interactions in CeO2 (111) Oxygen Vacancy Structure: Insights from Machine-Learning and Cluster Expansion
Beijing University of Chemical Technology（北京化工大学）；Shanghai Institute of Applied Physics, Chinese Academy of Sciences（中国科学院上海应用物理研究所）；Zhejiang University（浙江大学）；Shanghai Advanced Research Institute, Chinese Academy of Sciences（中国科学院上海高级研究院）；Fritz-Haber-Institut der Max-Planck-Gesellschaft（马克斯·普朗克学会弗里茨·哈伯研究所）；Humboldt-Universität zu Berlin（柏林洪堡大学）；Instituto de Catálisis y Petroleoquímica of the Consejo Superior de Investigaciones Científicas（西班牙国家科学研究理事会催化与石油化学研究所）
