CAREER: studying superconductivity and ferromagnetism in 2D material heterostructures with flat energy band

职业：研究具有平坦能带的二维材料异质结构中的超导性和铁磁性

• 批准号: 2143384
• 负责人: Jia Li
• 金额: $ 70万
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-02-15 至 2027-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2143384&HistoricalAwards=false
• 关键词: CAREER; studying; superconductivity; ferromagnetism; 2D

NON-TECHNICAL DESCRIPTION: Two-dimensional (2D) materials are materials made from single layers of atoms. Different 2D materials can be assembled into a designer structure to realize new properties and novel phenomena such as superconductivity and magnetism. This project utilizes a special design of 2D structure to study how electronic interaction can influence the stability of these novel phenomena, such as superconductivity and magnetism, in the quantum regime. Studying these phenomena on the nanometer scale is central to the advancement of quantum science, which promises to reshape the nature of technological innovation and has profound influence on national security and global economic balance. By training graduate and undergraduate students in device fabrication on a nanometer scale and exposing them to cutting edge research in studying quantum phenomena, this research and outreach program inspires and educates future scientists and engineers who can take on the leadership role and pioneer innovations in the field of quantum computational technology. The outreach effort includes collaboration with the Sci-Toon team to produce cartoon videos to expose the general public to the research activities. This project is jointly funded by the Division of Materials Research (DMR) and the Established Program to Stimulate Competitive Research (EPSCoR).TECHNICAL DESCRIPTION: Graphene moiré systems provides a fascinating material platform to study quantum phenomena, such as superconductivity and ferromagnetism, and investigate their interplay in a 2D confinement. This project utilizes specially designed 2D material heterostructure, which is usually referred to as the double-layer structure, to perform Coulomb screening and thermodynamic measurements on various moiré systems. A main objective is to understand the role of Coulomb correlation in stabilizing the superconducting and ferromagnetic phases. The role of Coulomb interaction offers important constraints to understand the pairing mechanism and order parameter symmetry of the superconducting phase, which has become an outstanding open question. This project also explores a new flavor of moiré physics using the proximity effect, which are shown to transform the ground state order of 2D moiré systems. By controlling the strength of Coulomb interaction through screening, the proposed effort directly studies the influence of the proximity effect and aims to establish a new method to engineer physical properties of 2D material structures. This project is jointly funded by the Division of Materials Research (DMR) and the Established Program to Stimulate Competitive Research (EPSCoR).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：二维 (2D) 材料是由单层原子制成的材料，可以将不同的 2D 材料组装成设计结构，以实现超导和磁性等新特性和新现象。二维结构的研究，以研究电子相互作用如何影响量子领域中这些新现象（例如超导性和磁性）的稳定性，在纳米尺度上研究这些现象是量子进步的核心。这项研究有望重塑技术创新的本质，并对国家安全和全球经济平衡产生深远影响。和外展计划激励和教育未来的科学家和工程师，他们可以在量子计算技术领域发挥领导作用并开拓创新。外展工作包括与 Sci-Toon 团队合作制作卡通视频，向公众展示。该项目由以下机构共同资助。材料研究部 (DMR) 和刺激竞争研究的既定计划 (EPSCoR)。技术描述：石墨烯莫尔系统提供了一个令人着迷的材料平台来研究量子现象，例如超导性和铁磁性，并研究它们在 2D 限制中的相互作用该项目利用专门设计的二维材料异质结构，即通常所说的双层结构，进行库仑筛选和计算。各种莫尔系统的热力学测量的一个主要目标是了解库仑相关性在稳定超导相和铁磁相中的作用库仑相互作用的作用为了解超导相的配对机制和有序参数对称性提供了重要的约束。该项目还利用邻近效应探索了一种新的莫尔条纹物理风格，它可以通过控制强度来改变二维莫尔条纹系统的基态顺序。通过筛选库仑相互作用，直接研究邻近效应的影响，旨在建立一种设计二维材料结构物理性能的新方法。该项目由材料研究部（DMR）和已建立的研究所共同资助。刺激竞争性研究计划 (EPSCoR)。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。

项目成果

Zero-field superconducting diode effect in small-twist-angle trilayer graphene

小扭转角三层石墨烯中的零场超导二极管效应

• DOI: 10.1038/s41567-022-01700-1
• 发表时间: 2021-12-15
• 期刊: Nature Physics
• 影响因子: 19.6
• 作者: Jiangxiazi Lin;Phum Siriviboon;H. Scammell;Song Liu;D. Rhodes;K. Watanabe;T. Taniguchi;J. Hone;M. Scheurer;J.I.A. Li
• 通讯作者: J.I.A. Li

Dirac revivals drive a resonance response in twisted bilayer graphene

狄拉克复兴驱动扭曲双层石墨烯的共振响应

• DOI: 10.1038/s41567-023-02060-0
• 发表时间: 2022-06-16
• 期刊: Nature Physics
• 影响因子: 19.6
• 作者: E. Morissette;Jiangxiazi Lin;Song Liu;D. Rhodes;K. Watanabe;T. Taniguchi;J. Hone;M. Scheurer
• 通讯作者: M. Scheurer