MRI: Development of Layered Quantum Materials Synthesis Facility

具有原子精度的工程电子材料将能够构建具有独特电子，磁性和光学特性的定制量子器件，并有可能影响从量子信息科学到下一代计算和清洁能源技术的领域。原子级精确的垂直结构可以通过堆叠具有不同特性的不同原子级薄材料来形成。各个层的特性及其新兴的相互作用，为基础科学和未来技术展示了巨大的希望。迄今为止，这一过程一直在手工规模上进行探索，并产生了丰富的科学发现。然而，这种异质结构的可扩展构造仍然是一个挑战，单个堆叠通常通过具有显著界面污染的艰苦手动过程来建立。该项目克服了这些挑战，并通过开发自动化机器人平台来实现原子分辨异质结构的可扩展生产，以在超高真空条件下组装层材料，从而产生用于生产具有前所未有的复杂性和界面清洁度的材料的工具。一旦开发出来，这个系统将被安置在斯坦福大学纳米工厂附近，在那里它将作为斯坦福大学研究人员在不同的跨学科社区的共享工具。此外，该项目将通过高级课程和研究机会加强本科生和研究生教育。该项目支持开发一种新型仪器，以自动化分层货车德瓦尔斯（vdW）异质结构形式的设计师量子材料的制造。专门利用剥离材料的现有工艺受到样品的随机性质的限制，导致对所得异质结构的低通量和几何约束。相比之下，该项目利用剥离和化学气相沉积（CVD）/分子束外延（MBE）生长的源材料，以提高产量和改善样品尺寸。该仪器采用互连的超高真空（UHV）腔室来保持原子级原始表面，并使用精密纳米定位平台，微结构粘合剂效应器，光学显微镜和计算机视觉算法，以实现用户友好，高通量的制造和沉积到任意衬底上。UHV样品制备室和真空手提箱有助于惰性样品处理，从而能够研究空气敏感的2D材料。大面积单晶石墨烯和hBN的集成原位UHV-CVD生长提供了对原始样品的访问，这对于具有受控旋转对准的vdW异质结构的研究至关重要。该仪器可以研究凝聚态物理和材料科学中的各种主题，包括扭曲多层结构中的工程强相关相，异质界面处的新兴拓扑超导性以及单缺陷量子器件的精确定位研究。该仪器的五年开发项目使斯坦福大学的研究人员组成的多元化团队能够探索这些现象，并为学术界和工业界的合作提供了一个核心点。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

Engineering electronic materials with atomic precision will enable construction of tailored quantum devices exhibiting unique electronic, magnetic and optical properties, with the potential to impact fields ranging from quantum information science to next-generation computing and clean energy technologies. Atomically precise vertical structures can be formed by stacking different atomically-thin materials with diverse characteristics. The properties of individual layers, and their emergent interactions, show great promise for fundamental science and future technologies. To date, this process has been explored at the artisanal scale and has generated a wealth of scientific discoveries. However, the scalable construction of such heterostructures has remained a challenge, with individual stacks often built up though painstakingly manual processes with significant interfacial contamination. This project overcomes these challenges and enables scalable production of atomically-resolved heterostructures by developing an automated robotic platform to assemble layer materials under ultra-high vacuum conditions, resulting in a tool for production of materials with unprecedented complexity and interfacial cleanliness. Once developed, this system will be housed adjacent to the Stanford Nanofabrication Facility, where it will serve as a shared tool for Stanford researchers across a diverse interdisciplinary community. Additionally, this project will enhance undergraduate and graduate education through advanced coursework and research opportunities.This project supports development of a novel instrument to automate the fabrication of designer quantum materials in the form of layered van der Waals (vdW) heterostructures. Existing processes which exclusively utilize exfoliated materials are limited by the stochastic nature of the samples, resulting in low throughput and geometric constraints on the resulting heterostructure. In contrast, this project utilizes both exfoliated and chemical vapor deposition (CVD)/molecular beam epitaxy (MBE)-grown source materials for enhanced throughput and improved sample size. The instrument employs interconnected ultra-high vacuum (UHV) chambers to maintain atomically pristine surfaces, and uses precision nanopositioning stages, microstructured adhesive effectors, an optical microscope, and computer vision algorithms to enable user-friendly, high-throughput fabrication and deposition onto arbitrary substrates. The UHV sample preparation chamber and vacuum suitcase facilitate inert sample processing, enabling study of air-sensitive 2D materials. Integrated in-situ UHV-CVD growth of large area, single-crystal graphene and hBN provide access to pristine samples which are critical to the investigation of vdW heterostructures with controlled rotational alignment. This instrument enables the study of diverse topics in condensed matter physics and materials science, including engineered strongly correlated phases in twisted many-layer structures, emergent topological superconductivity at heterointerfaces, and precisely localized studies of single-defect quantum devices. The five-year development project for this instrument enables a diverse team of Stanford researchers to explore these phenomena, and provides a nucleation point for collaboration across academia and industry.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.