Spatially resolved spectroscopy of Quantum Materials: Scanning probe Microscopy control system for high-resolution tunnelling spectroscopy

量子材料的空间分辨光谱：用于高分辨率隧道光谱的扫描探针显微镜控制系统

• 批准号: RTI-2022-00171
• 负责人: Burke, Sarah
• 金额: $ 10.93万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Research Tools and Instruments
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=743037
• 关键词: Spatially; resolved; spectroscopy; Quantum; Materials

Quantum materials exhibit a rich phenomenology of electronic states ranging from superconductors to correlated insulators, arising from the enormous phase space that the periodic table provides to multicomponent materials. This large phase space of materials also presents new challenges for characterization as many materials exhibit variations in crystal structure, and small changes in composition, defect density and type of defect can tip these sensitive systems into different electronic phases. This potential for inhomogeneity and extreme sensitivity to impurities makes local probe techniques that can provide high resolution spectroscopic characterization of the electronic structure an essential tool for quantum materials research. Scanning probe microscopy methods, most notably Scanning Tunnelling Microscopy and Spectroscopy (STM, STS), provide local structural and electronic characterization of surfaces on the atomic scale. With dramatic advances in instrumentation in the past 15 years, such spectroscopy measurements can now be taken at each pixel, rather than selected points, opening up access to both studies of spatial inhomogeneity of the electronic structure and a connection to the "k-space" picture that drives much of condensed matter understanding through quasiparticle interference (QPI) measurements. These measurements provide unprecedented insight into the influence of local variations in structure, charge donation, and defects, while simultaneously allowing us to measure how electrons scatter providing insight into symmetries and textures of the electronic states, such as the superconducting gap and topological features. Here, we request an SPM controller upgrade for an existing CFI-funded 1K STM/AFM system with 3T magnetic field coupled to an APRES chamber to allow for the high-quality spectroscopic measurements demanded by the Quantum Materials field, as the existing controller does not allow for the flexibility required to obtain sufficiently high-quality data to map local variations in electronic structure or produce high-quality QPI measurements needed to convincingly answer key questions in this area. Three lines of research are described, providing examples of the types of studies possible and their demands on instrumentation: Topological properties of rare-earth square net materials, Surface texture of superconductivity in a polar Fe-based superconductor, and the Search for topological superconductivity in thin films. Each requires high-spatial and energy resolution for real and/or k-space characterization of the electronic structure, and requires access to <4K temperatures and magnetic fields to explore the most exciting regimes of the electronic structures of these materials.

量子材料表现出从超导体到相关绝缘子的电子状态的丰富现象学，这是由周期表提供给多组分材料的巨大相空间所产生的。由于许多材料在晶体结构中表现出差异，并且组成密度和缺陷类型的小变化可以将这些敏感的系统倾斜到不同的电子相。这种不均匀性和对杂质极端敏感性的潜力使局部探针技术可以提供高分辨率的电子结构表征，这是量子材料研究的重要工具。扫描探针显微镜方法，最著名的是扫描隧道显微镜和光谱法（STM，STS），在原子尺度上提供了表面的局部结构和电子表征。在过去15年中仪器方面的巨大进步中，现在可以在每个像素而不是选定点上进行这种光谱测量值，从而可以访问两种电子结构的空间不均匀性研究，并与“ K-Space”图片连接，从而通过quasiparticle criparticle Interference（qpi）测量来吸引大量的凝结物质理解。这些测量结果为局部变化在结构，电荷捐赠和缺陷中的影响提供了前所未有的见解，同时允许我们测量电子如何散布对电子状态的对称性和纹理（例如超导间隙差距和拓扑特征）的见解。在这里，我们要求SPM控制器升级现有的CFI资助的1K STM/AFM系统，其3T磁场耦合到APRES室，以允许量子材料领域所需的高质量光谱测量值，因为现有控制器无法获得足够的灵活性，以绘制足够高的量化范围，以绘制高质量的质量数据，以衡量高质量的范围，以电子量的质量量化，以电子量的质量量化，以电子量的质量量化量，以使电子变量逐渐变化。回答该领域的关键问题。描述了三条研究线，提供了可能的研究类型及其对仪器的需求的例子：稀土平方净材料的拓扑特性，极性基于极性Fe的超导体中超导性的表面纹理以及在薄膜中寻找拓扑超导性。每个都需要高空间和能量分辨率，以实现电子结构的真实和/或k空间表征，并且需要进入<4K的温度和磁场，以探索这些材料电子结构的最令人兴奋的机制。