Postdoctoral Fellowship: MPS-Ascend: Moire Engineering in van der Waals Heterostructures

博士后奖学金：MPS-Ascend：范德华异质结构中的莫尔工程

• 批准号: 2317067
• 负责人: Tara Pena
• 金额: $ 30万
• 依托单位: Pena, Tara
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-15 至 2026-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2317067&HistoricalAwards=false
• 关键词: Postdoctoral; Fellowship; MPS; Ascend; Moire

Non-technical DescriptionSemiconductors made from a single atomic layer profoundly differ from bulk crystals. For example, two-dimensional (2D) materials combine high mechanical strength and an assortment of tunable electrical properties. One can also make heterostructures with unique functionality by stacking different crystals together. A promising way to control material properties is to vary the relative orientation of two atomically thin layers to create a nanoscale moiré pattern. Such moiré structures have the potential to enable new classes of devices for energy efficient computing and other applications. Currently, the only way to make and control moiré interference patterns is by physically stacking and rotating individual layers. This project will explore the control of moiré lattices by applying mechanical force (strain). Strain engineering is compatible with any type of 2D heterostructure, and thus could enable a wide range of novel devices. Given the enormous amount of energy required for artificial intelligence and data centers, this work could impact everyday technology across the globe. The PI will amplify impact of this work through by mentoring undergraduate students and involving them in research. She will also involve local high school students with hands on experimental work, inspiring a new generation of scientists and engineers.Technical DescriptionThe goal of this MPS-Ascend research project is to obtain a comprehensive understanding of correlated electronic states available in twisted bilayer graphene with respect to both heterostrain (magnitude and direction) and twist angle biases. This systematic study will provide the community a template on how to reliably access and control correlated electron phenomena such as superconductivity in twisted bilayer graphene heterostructures. In addition, we will investigate how to create and control moiré interference patterns in heterostrained non-twisted bilayer graphene structures, then again systematically examine correlated electronic properties with respect to heterostrain application alone. Upon successfully obtaining a moiré interference through heterostrained non-twisted bilayers, this will allow moiré heterostructures to be obtained in a scalable, controllable fashion that can be integrated with industrial nanofabrication processes. As this method is scalable and compatible with any van der Waals based heterostructure, the work can be extended to control more properties dictated by moiré interference patterns and enable device structures that leverage the exotic properties hosted by moiré superlattices.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.

非技术性描述由单个原子层制成的半导体与大块晶体有很大的不同。例如，二维（2D）材料联合收割机结合了高机械强度和各种可调电性能。人们还可以通过将不同的晶体堆叠在一起来制造具有独特功能的异质结构。控制材料特性的一种有希望的方法是改变两个原子级薄层的相对取向，以创建纳米级莫尔图案。这种莫尔结构具有使新类别的设备能够用于节能计算和其他应用的潜力。目前，制作和控制莫尔干涉图案的唯一方法是通过物理堆叠和旋转各个层。本项目将探索通过施加机械力（应变）来控制莫尔晶格。应变工程与任何类型的2D异质结构兼容，因此可以实现各种各样的新型器件。鉴于人工智能和数据中心需要大量的能源，这项工作可能会影响地球仪的日常技术。PI将通过指导本科生并让他们参与研究来扩大这项工作的影响。她还将让当地高中生亲自参与实验工作，激励新一代的科学家和工程师。技术说明这个MPS-Ascend研究项目的目标是全面了解扭曲双层石墨烯中的相关电子态，包括异质应变（大小和方向）和扭曲角度偏差。这项系统性的研究将为社区提供一个模板，说明如何可靠地访问和控制相关的电子现象，如扭曲双层石墨烯异质结构中的超导性。此外，我们将研究如何在异质应变非扭曲双层石墨烯结构中创建和控制莫尔干涉图案，然后再次系统地研究与异质应变应用相关的电子特性。在通过异质应变非扭曲双层成功获得莫尔干涉后，这将允许以可扩展、可控的方式获得莫尔异质结构，其可以与工业纳米纤维工艺集成。由于这种方法是可扩展的，并与任何货车范德华基异质结构兼容，这项工作可以扩展到控制更多的属性所决定的莫尔干涉图案，并使器件结构，利用外来属性托管莫尔超lattices.This奖项反映了NSF的法定使命，并已被认为是值得通过评估使用基金会的智力价值和更广泛的影响审查标准的支持。