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.

非技术描述由单原子层制成的半导体与块状晶体有很大不同，例如，二维 (2D) 材料结合了高机械强度和各种可调节的电性能，还可以通过堆叠不同的晶体来制造具有独特功能的异质结构。控制材料特性的一种有前途的方法是改变两个原子薄层的相对方向，以创建纳米级莫尔图案，这种莫尔结构有潜力实现新型节能计算设备。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，该项目将探索通过应用与任何类型的机械力（应变）来控制莫尔条纹。二维异质结构，因此可以实现各种新颖的设备，考虑到人工智能和数据中心所需的大量能源，这项工作可能会影响全球的日常技术，PI 将通过指导本科生来扩大这项工作的影响。学生她还将让当地的高中生参与实验工作，激励新一代的科学家和工程师。技术说明该 MPS-Ascend 研究项目的目标是全面了解现有的相关电子态。扭曲双层石墨烯在异质应变（大小和方向）和扭曲角度偏差方面的研究将为业界提供如何可靠地访问和控制相关电子现象（例如扭曲双层石墨烯中的超导性）的模板。此外，我们将研究如何在异质非扭转双层石墨烯结构中创建和控制莫尔干涉图案，然后通过检查异质非扭转成功获得莫尔干涉，然后再次系统地关联异质结构的电子特性。双层，这将使莫尔异质结构能够以可扩展、可控的方式获得，并且可以与工业纳米制造工艺集成，因为这种方法是可扩展的并且与任何货车兼容。基于德瓦尔斯的异质结构，这项工作可以扩展到控制由莫尔干涉图案决定的更多属性，并使设备结构能够利用莫尔超晶格所具有的奇异属性。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。