RII Track-4:NSF: Resistively-Detected Electron Spin Resonance in Multilayer Graphene

RII Track-4：NSF：多层石墨烯中电阻检测的电子自旋共振

• 批准号: 2327206
• 负责人: Jia Li
• 金额: $ 30万
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-01-01 至 2025-12-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2327206&HistoricalAwards=false
• 关键词: RII; Track; NSF; Resistively; Detected

This Research Infrastructure Improvement Track-4 EPSCoR Research Fellows project will provide a fellowship to an Assistant Professor and training for a postdoctoral fellow at Brown University. Spin is an intrinsic property of electrons, which is key to understanding electronic properties of quantum materials at low temperatures. For instance, magnetism occurs when spins of many electrons align in a preferred direction, whereas the nature of superconductivity is crucially dependent on the spin configuration of the underlying electron pairs. In atomically thin materials consisting of two to three layers of carbon atoms, the reduced dimension enhances Coulomb correlation (describes the correlation between the spatial position of electrons due to their Coulomb repulsion), which further amplifies the role of electronic spin. This project aims to develop an experimental method to directly probe the configuration of electron spins in these 2D materials. The proposed effort takes advantage of the state-of-the-art user facility at the National High Magnetic Field Lab. By exposing students and researchers to cutting-edge research in the national lab, the research and outreach program inspires and educates future scientists and engineers to take on leadership roles and pioneer innovations in the field of quantum science and quantum material research. The research project also aims to establish a user program located in Rhode Island, which promises to have wide wide-ranging impact on training Rhode Island’s quantum-deficient workforce by providing research and intern positions for different levels of students.The low-temperature phase diagram of strongly correlated 2D materials hosts many exotic quantum phases, such as superconductivity and ferromagnetism. To understand the microscopic origin underlying these emergent phenomena, it is key to first identify the exact configuration of electronic spin. However, the lack of viable experimental methods presents a hurdle to uncovering the order in the spin degrees of freedom, which gives rise to one of the main challenges for research efforts aiming to better understand the nature of electronic states in 2D materials such as multilayer graphene. In this proposal, the PI puts forth a new paradigm of experimental methods that are capable of directly probing the nature of electronic spin, which utilizes resistively detected electron spin resonance measurement. Moreover, The PI will investigate the Coulomb-driven process of spontaneous rotational symmetry breaking. Recent experimental progress demonstrated that spontaneous rotational symmetry breaking can be characterized based on angle-resolved nonreciprocal transport measurement. Building on these developments, the proposed research project will investigate the electronic spin configuration in multilayer graphene, such as Bernal stacked bilayer graphene and magic-angle twisted trilayer graphene, along with its connection to the process of spontaneous rotational symmetry breaking. Results from this project will have a far-reaching impact by providing new insights into the nature of electronic orders stabilized by the interplay between strong correlation and nontrivial topology. The proposed project will utilize the state-of-the-art user facility at the National High Magnetic Field Lab (NHMFL), where capable staff scientists provide strong technical support.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.

该研究基础设施改进 Track-4 EPSCoR 研究员项目将为布朗大学的助理教授提供奖学金，并为博士后研究员提供培训。自旋是电子的固有属性，是理解低温下量子材料的电子属性的关键。例如，当许多电子的自旋沿首选方向排列时，就会产生磁性，而超导性的本质主要取决于底层电子对的自旋构型，在由两到三层碳原子组成的原子薄材料中，超导性的本质是减少的。方面增强了库仑相关性（描述电子由于库仑斥力而导致的空间位置之间的相关性），这进一步放大了电子自旋的作用。该项目旨在开发一种实验方法来直接探测这些二维材料中电子自旋的配置。拟议的工作利用国家高磁场实验室最先进的用户设施，通过让学生和研究人员接触国家实验室的前沿研究，该研究和推广计划激励和教育未来的科学家和学生。该研究项目还旨在在罗德岛州建立一个用户计划，该计划有望对罗德岛州的量子培训产生广泛的影响。通过为不同水平的学生提供研究和实习职位来弥补劳动力不足的问题。强相关二维材料的低温相图包含许多奇异的量子相，例如超导性和铁磁性。是首先确定电子自旋精确构型的关键，然而，缺乏可行的实验方法给揭示自旋自由度的顺序带来了障碍，这给旨在更好地理解电子自旋的研究工作带来了主要挑战之一。二维材料（例如多层石墨烯）中电子态的性质在该提案中，PI 提出了一种能够直接探测电子自旋性质的新实验方法，该方法利用电阻检测的电子自旋共振测量。将调查自发旋转对称破缺的库仑驱动过程。最近的实验进展表明，自发旋转对称破缺可以基于角度分辨的非互易输运测量来表征，拟议的研究项目将研究多层石墨烯中的电子自旋构型。例如伯纳尔堆叠双层石墨烯和魔角扭曲三层石墨烯，及其与自发旋转对称破缺过程的联系，该项目的结果将通过提供对自然的新见解而产生深远的影响。通过强相关性和非平凡拓扑之间的相互作用来稳定电子秩序。拟议的项目将利用国家强磁场实验室（NHMFL）最先进的用户设施，那里有能力的科学家提供强大的技术支持。授予 NSF 的法定使命，并通过评估反映使用基金会的智力优点和更广泛的影响审查标准，被认为值得支持。