DMREF Collaborative Research: Establishing the Platform of Quasi-one-dimensional Topological Insulators with Emergent Functionalities

DMREF合作研究：建立具有突发功能的准一维拓扑绝缘体平台

• 批准号: 1921581
• 负责人: Fan Zhang
• 金额: $ 70万
• 依托单位: University of Texas at Dallas
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-10-01 至 2023-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1921581&HistoricalAwards=false
• 关键词: DMREF; Collaborative; Research; Establishing; Platform

Non-technical Description: Applying the concept of topology to solid state systems has revolutionized our understanding of quantum phenomena and materials, and inspired the design of new functionalities in electronic, atomic, photonic, mechanical, and acoustic systems. For instance, topological insulators (TIs) are a class of materials that are electrically insulating in the bulk, but host conductive surface states. Protected by symmetry and topology, these surface states are immune to impurities and thus enable making near-perfect devices from imperfect interfaces, which are important for both conventional and quantum information technology. However, there exist a number of critical challenges in current TI materials that must be addressed before realizing their full potential. This project aims at overcoming these challenges by focusing on a new class of materials, quasi-one-dimensional (quasi-1D) TIs with emergent functionalities. An iterative loop of theoretical modeling and prediction, material synthesis, and characterization will be established to discover different families of quasi-1D TIs and explore their unique properties for topological phenomena and functionalities. The project's success will shed light on the realization of topological quantum computing and low-power spintronics for next-generation information technology and sustainable energy solutions. Major educational activities will be integrated into the research activities by performing public outreach, training graduate and undergraduate students, increasing participation of under-represented groups, providing a new face to physics and materials science with two women in leadership positions on this team, and offering open access to research and education outputs to the technical community and general public.Technical Description: To date, most of the identified TIs are either strongly bonded bulk materials or layered van der Waals materials. Despite their richness, fundamental obstacles and limitations exist in exhibiting the decisive properties and realizing the full promise of TIs, such as the restriction of surface Dirac cones to a specific cleavage plane, weak electronic interactions and limited tunability. Remarkably, a quasi-1D structure promises to overcome these challenges. The goals of this project include design and optimization of quasi-1D TI candidates, synthesis and characterization, tuning topological phase transitions by strain and temperature, and seeking 2D TIs in atomically thin layers of quasi-1D materials. Through complementary expertise and concerted efforts on theory and computation, material synthesis, spin- and angle-resolved photoemission spectroscopy, nanofabrication, quantum transport, and neutron and x-ray scattering, the project is expected to lead to the discovery of novel TIs, phases and phenomena, controlling topological transitions, and enabling superior functionalities and fostering quantum technologies.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：将拓扑的概念应用于固态系统已经彻底改变了我们对量子现象和材料的理解，并启发了电子，原子，光子，机械和声学系统中新功能的设计。例如，拓扑绝缘子（TIS）是一类材料，它们是在散装中进行电绝缘的，但寄主导电表面状态。这些表面状态受对称和拓扑的保护，对杂质不受欢迎，因此可以从不完美的接口制造近乎完美的设备，这对于常规和量子信息技术都很重要。但是，在目前的TI材料中存在许多关键挑战，必须在意识到它们的全部潜力之前要解决。该项目旨在通过专注于新的材料，即具有紧急功能的新材料，准二维（Quasi-1d）TI来克服这些挑战。将建立一个理论建模和预测，材料合成和表征的迭代循环，以发现准-1D的不同家族，并探索它们在拓扑现象和功能方面的独特特性。该项目的成功将阐明实现下一代信息技术和可持续能源解决方案的拓扑量子计算和低功率旋转技术。主要的教育活动将通过进行公众的外展，培训研究生和本科生，越来越多地参与不足的团体的参与，为这支团队的领导职位提供了针对物理和材料科学的新面孔，并为技术社区和一般公众提供了良好的材料，大多数材料都在供应，这要么是强大的材料。尽管它们具有丰富的性能，但在表现出决定性特性并实现了TIS的全部希望中仍然存在基本障碍和局限性，例如将表面狄拉克锥限制为特定的切割平面，弱电子相互作用和有限的可调性。值得注意的是，准1D结构有望克服这些挑战。该项目的目标包括设计和优化准1D TI候选物，合成和表征，通过应变和温度调整拓扑相变，以及在原子较薄的准1D材料中寻求2D TIS。通过互补的专业知识以及在理论和计算，材料合成，旋转和角度分辨光学光谱，纳米型，量子运输以及中子和X射线散射方面的一致努力，预计该项目将导致新的TIS，阶段和现象，从而控制拓扑的量化和启用量的功能性，并授予量化量的范围。使命，并被认为是通过基金会的知识分子优点和更广泛影响的审查标准通过评估值得支持的。

项目成果

Uncovering Topological Edge States in Twisted Bilayer Graphene

揭示扭曲双层石墨烯中的拓扑边缘态

• DOI: 10.1021/acs.nanolett.2c01481
• 发表时间: 2022
• 期刊: Nano Letters
• 影响因子: 10.8
• 作者: Fortin-Deschênes, Matthieu;Pu, Rui;Zhou, Yan-Feng;Ma, Chao;Cheung, Patrick;Watanabe, Kenji;Taniguchi, Takashi;Zhang, Fan;Du, Xu;Xia, Fengnian
• 通讯作者: Xia, Fengnian

Evidence for Dirac flat band superconductivity enabled by quantum geometry

• DOI: 10.1038/s41586-022-05576-2
• 发表时间: 2023-02
• 期刊: Nature
• 影响因子: 64.8
• 作者: Haidong Tian;Xue-Jian Gao;Yuxin Zhang;S. Che;Tianyi Xu;Patrick Cheung;Kenji Watanabe;T. Taniguchi;M. Randeria;Fan Zhang;C. N. Lau;M. Bockrath

Impact of Electric Field Disorder on Broken-Symmetry States in Ultraclean Bilayer Graphene

电场无序对超净双层石墨烯破缺对称态的影响

• DOI: 10.1021/acs.nanolett.2c02119
• 发表时间: 2022
• 期刊: Nano Letters
• 影响因子: 10.8
• 作者: Geisenhof, Fabian R.;Winterer, Felix;Seiler, Anna M.;Lenz, Jakob;Zhang, Fan;Weitz, R. Thomas
• 通讯作者: Weitz, R. Thomas

Unconventional valley-dependent optical selection rules and landau level mixing in bilayer graphene

• DOI: 10.1038/s41467-020-16844-y
• 发表时间: 2020-06
• 期刊: Nature Communications
• 影响因子: 16.6
• 作者: L. Ju;Lei Wang;Xiao Li;S. Moon;M. Ozerov;Zhengguang Lu;T. Taniguchi;Kenji Watanabe;E. Mueller;Fan Zhang;D. Smirnov;F. Rana;P. McEuen

New layered quaternary BaCu6Sn2As4−x and BaCu6Sn2P4−x phases: Crystal growth and physical properties

• DOI: 10.1016/j.jallcom.2021.162111
• 发表时间: 2022
• 期刊: Journal of Alloys and Compounds
• 影响因子: 6.2
• 作者: Hanlin Wu;Sheng Li;Xiqu Wang;Sunah Kwon;Wenhao Liu;Gareth A. Ofenstein;Moon J. Kim;B. Lv