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.

这项研究基础设施改进Track-4 Epscor Research Fellows项目将为Brown University的一名博士后研究员提供助理教授和培训奖学金。自旋是电子的内在特性，这是了解低温下量子材料的电子特性的关键。例如，当许多电子的旋转沿首选方向对齐时，就会发生磁性，而超导性的性质基本上取决于基础电子对的自旋构型。在由两到三层碳原子组成的原子薄材料中，降低尺寸增强了库仑相关性（描述了由于其库仑排斥而引起的电子空间位置之间的相关性），这进一步放大了电子旋转的作用。该项目旨在开发一种实验方法，以直接探测这些2D材料中电子旋转的配置。拟议的努力利用了国家高磁场实验室的最先进的用户设施。通过使学生和研究人员在国家实验室中进行尖端研究，研究和外展计划激发了和教育未来的科学家和工程师，从而在量子科学和量子材料研究领域扮演领导角色和先锋创新。该研究项目还旨在建立位于罗德岛州的用户计划，该计划有望通过为不同级别的学生提供研究和实习职位，对训练罗德岛的量子缺陷型员工产生广泛的影响。强烈相关的2D材料的低温相图托有许多异体量子阶段，例如许多异国情调的量子阶段，例如超级导率和超级导率和效能运动。要了解这些新兴现象的基础微观起源，首先确定电子自旋的确切构型是关键。但是，缺乏可行的实验方法为揭示自旋转自由度的顺序带来了一个障碍，这引起了研究工作的主要挑战之一，旨在更好地了解2D材料（例如多层石墨烯）中电子状态的性质。在此提案中，PI提出了一个新的实验方法范式，该方法能够直接探测电子自旋的性质，该方法利用了可抵抗的电子自旋共振测量。此外，PI将研究赞助商 - 旋转对称性破坏的库仑驱动过程。最近的实验进展表明，可以根据角度分辨的非偏射转运测量来表征赞助商分辨的旋转对称性破裂。在这些发展的基础上，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Bernal堆叠的双层石墨烯和魔法角扭曲的三层石墨烯，以及它与赞助商增强型旋转对称性的过程的连接。该项目的结果将通过对通过强相关和非平凡拓扑之间的相互作用稳定的电子订单的性质提供新的见解，从而产生深远的影响。拟议的项目将利用国家高磁场实验室（NHMFL）的最先进的用户设施，在那里有能力的员工科学家提供强有力的技术支持。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子优点和更广泛的影响审查标准来评估来获得的支持。