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：开发具有新特性的材料对于保持国家在新兴量子技术方面的领导地位至关重要。其中一些新特性包括“非线性霍尔效应”和“谷霍尔效应”，它们对量子设备和下一代无线网络等应用具有吸引力。这个项目包括生产这些材料，研究它们的性质以及它们在室温下的功能。该项目为培养学生提供了丰富的机会，使他们成为未来高科技行业的劳动力。本科生，包括那些来自代表性不足的少数群体的学生，将被招募和培训来种植材料并进行测量以发现它们的特性。当地高中学生也将参与“Make it Matter营”外展活动。技术描述：提出了材料电子结构中的谷自由度作为一种新的信息载体形式。当谷自由度与破缺反转对称性和强自旋轨道耦合结合时，可以产生以自旋谷锁定为特征的独特电子态，从而产生谷和非线性霍尔效应等奇异量子输运现象。这些新概念为谷电子和太赫兹探测器等新设备的应用奠定了基础。本项目旨在展示自旋锁谷Dirac半金属BaMnSb2和其他几种材料的室温体非线性霍尔效应和谷霍尔效应。该项目的首席研究员通过单晶生长、微尺度霍尔器件制造、非线性输运测量和光学成像来实现这些目标。谷霍尔效应仅在二维材料中观察到，但从未报道过任何块状材料。虽然非线性霍尔效应之前在几种2D/3D材料中得到了证明，但它主要是一种低温现象。室温体非线性霍尔效应尚未实现。该研究项目将为教学、培训和学习创造丰富的机会。几名本科生，包括少数族裔学生，接受培训，种植项目中使用的单晶，并在每个项目年进行运输测量。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识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

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