Topological quantum transport properties in spin-valley locked Dirac semimetals

自旋谷锁定狄拉克半金属的拓扑量子输运特性

• 批准号: 2211327
• 负责人: Zhiqiang Mao
• 金额: $ 43.54万
• 依托单位: Pennsylvania State Univ University Park
• 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: 2022-07-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2211327&HistoricalAwards=false
• 关键词: Topological; quantum; transport; properties; spin

NON-TECHNICAL DESCRIPTION: Developing materials with novel properties is essential for sustaining the nation’s leadership in emerging quantum technologies. Some of those novel properties include “nonlinear Hall effect” and “valley Hall effect” which are attractive for applications such as quantum devices and next-generation wireless networks. This project involves producing these materials and investigating these properties as well as their ability to function at room temperature. The project provides rich opportunities for training students and preparing them as future workforce in high-tech industries. Undergraduate students, including those from the underrepresented minority groups, will be recruited and trained to grow the materials and perform measurements to discover their properties. Local high school students will also be engaged through their participation in the “Make it Matter Camp” outreach. TECHNICAL DESCRIPTION: The valley degree of freedom in the electronic structure of a material has been proposed as a new form of information carrier. When the valley degree of freedom is combined with broken inversion symmetry and strong spin-orbital coupling, it can create a unique electronic state characterized by spin-valley locking, resulting in exotic quantum transport phenomena such as the valley and nonlinear Hall effects. These new concepts lay a foundation for new device applications such as valleytronics and terahertz detectors. This project aims to demonstrate room-temperature bulk nonlinear-Hall and valley-Hall effects in spin-valley-locked Dirac semimetal BaMnSb2 and several other materials. The principal investigator of this project pursues these goals through bulk single crystal growth, microscale Hall device fabrications, nonlinear transport measurements, and optical imaging. The valley Hall effect was observed only in two-dimensional materials but never reported for any bulk materials. Although the nonlinear Hall effect was previously demonstrated in several 2D/3D materials, it is a primarily low-temperature phenomenon. The room-temperature bulk nonlinear Hall effect is yet to be realized. This research project will generate rich opportunities for teaching, training, and learning. Several undergraduate students, including underrepresented minority students, are trained to grow the single crystals used in this project and perform transport measurements in each project year.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：开发具有新颖性能的材料对于维持该国在新兴量子技术方面的领导力至关重要。其中一些新型属性包括“非线性大厅效应”和“山谷厅效应”，这些效果对量子设备和下一代无线网络等应用具有吸引力。该项目涉及生产这些材料并研究这些特性及其在室温下运作的能力。该项目为培训学生提供丰富的机会，并为他们作为高科技行业的未来劳动力做好准备。将招募和培训本科生，包括代表性不足的少数群体的学生，以种植材料并进行测量以发现其财产。当地的高中生也将通过参加“ Make It Matter Camp”外展活动来订婚。技术描述：已经提出了材料电子结构的自由度，作为一种新的信息载体形式。当山谷的自由度与破裂的反转对称性和强旋转轨道耦合相结合时，它可以创建一个独特的电子状态，其特征在于自旋 - 瓦利锁定，从而产生异国情调的量子传输现象，例如山谷和非线性霍尔效应。这些新概念为诸如Valleytronics和Terahertz探测器等新设备应用奠定了基础。该项目旨在展示自旋 - 瓦利锁的狄拉克半米BAMNSB2和其他几种材料中的室温散装非线性霍尔和山谷大厅的效果。该项目的主要研究人员通过大量的单晶增长，微观霍尔设备捏造，非线性传输测量和光学成像来追求这些目标。山谷大厅的效应仅在二维材料中观察到，但从未报告任何散装材料。尽管以前在几种2D/3D材料中证明了非线性大厅的效应，但它是一种原发性低温现象。室温散装非线性大厅效应仍有待实现。该研究项目将为教学，培训和学习带来丰富的机会。培训了几名本科生，包括代表人数不足的少数族裔学生，可以在每个项目年内培训该项目中使用的单晶体并进行运输测量。该奖项反映了NSF的法定任务，并通过使用基金会的知识分子优点和更广泛的影响审查标准来通过评估来诚实地支持支持。

项目成果

Coupling Between Magnetic and Transport Properties in Magnetic Layered Material Mn2-xZnxSb

• DOI: 10.1016/j.actamat.2023.119251
• 发表时间: 2023-08
• 期刊: Acta Materialia
• 影响因子: 9.4
• 作者: Md Rafique Un Nabi;R. Basnet;K. Pandey;S. Chhetri;Dinesh Upreti;Gokul Acharya;Fei Wang;A. Fereidouni;H. Churchill;Yingdong Guan;Z. Mao;Jin Hu

Large anomalous Hall effect and negative magnetoresistance in half-topological semimetals

• DOI: 10.1038/s42005-023-01469-6
• 发表时间: 2023-11
• 期刊: Communications Physics
• 影响因子: 5.5
• 作者: Yanglin Zhu;Cheng-Yi Huang;Yu Wang;David Graf;Hsin Lin;Seng Huat Lee;John Singleton;L. Min;J. C. Palmstrom;Arun Bansil;Bahadur Singh;Zhiqiang Mao