A tango between magnons and phonons in 2D van der Waals insulating magnets

二维范德华绝缘磁体中磁子和声子之间的探戈

• 批准号: 2219046
• 负责人: Xianglin Ke
• 金额: $ 41.74万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-01-01 至 2025-12-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2219046&HistoricalAwards=false
• 关键词: tango; between; magnons; phonons; 2D

Non-technical:Magnons and phonons, which are quanta of spin waves and lattice vibrations respectively, represent two fundamental collective excitations in condensed matter. In general, magnons and phonons are studied separately. Nevertheless, in magnetic solids with strong spin-lattice interactions, magnon-phonon coupling plays a key role in determining magnetic and thermal properties. Thus far, experimental studies of magnon-phonon coupling in van der Waals magnets, which emerge as a fertile playground for the discovery of novel physical phenomena, remain a largely unexplored research frontier. This project studies the magnon-phonon coupling in van der Waals insulating magnets by utilizing neutron scattering and thermal transport techniques. This project offers an excellent educational experience for young researchers to utilize cutting-edge facilities for scientific research on quantum materials. In addition to training graduate and undergraduate students, this project also supports scientific research activities by engaging K-12 students, attracting underrepresented students to research, and developing workshops. Importantly, this project serves as a platform to train the next-generation of neutron scattering scientists and therefore grows the user community of cutting-edge facilities in national laboratories. Technical:This project studies magnon-phonon coupling in van der Waals insulating magnets to understand the roles of magnons, phonons, and magnon-phonon coupling on thermal transport and thermodynamics of these systems. Specifically, the work addresses the following key scientific questions with neutron scattering and thermal transport techniques: (i) how does the magnon-phonon coupling depend on the symmetry of magnetic ground states? (ii) how does the spin-lattice interaction depend on the electron occupancy on d orbitals of magnetic transition-metal ions, and what is the impact of this on the magnon-phonon coupling? (iii) How does the magnon-phonon coupling vary with the spin-orbit interaction? (iv) How does the magnon-phonon coupling affect materials’ thermal transport and thermodynamics properties? The answers to these questions provide unprecedented knowledge about the coupling between magnons and phonons as well as their impact on thermal properties of van der Waals materials, which are essential for applications of these materials in spin caloritronics and magnon spintronics.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：分别是旋转波和晶格振动的量子的磁子和声子，代表了凝结物质中的两个基本集体令人兴奋。通常，分别研究了磁子和声子。然而，在具有较强的自旋晶格相互作用的磁性固体中，镁 - 光子耦合在确定磁性和热性能中起着关键作用。范德华磁铁中磁杆耦合的远处的实验研究，它是发现新型物理现象的肥沃游乐场，仍然是一个意外的研究前沿。该项目通过利用中子散射和热运输技术研究了范德华岛绝缘磁铁中的磁孔耦合。该项目为年轻研究人员提供了极好的教育经验，可以利用尖端的设施进行量子材料的科学研究。除了培训毕业生和本科生外，该项目还通过吸引K-12学生，吸引代表性不足的学生进行研究和开展讲习班来支持科学研究活动。重要的是，该项目是培训中子散射科学家的下一代的平台，因此扩大了国家实验室中尖端设施的用户社区。技术：该项目研究了范德华（Van der Waals）中绝缘磁铁中的磁通偶联，以了解镁，声子和磁通偶联在这些系统的热传输和热力学上的作用。具体而言，该工作通过中子散射和热传输技术解决了以下关键科学问题：（i）磁成功耦合如何取决于磁接地态的对称性？ （ii）自旋晶格的相互作用如何取决于磁过渡金属离子的d轨道的电子发生，并且它对磁通偶联有什么影响？ （iii）镁 - 音波耦合如何随旋转轨道相互作用而变化？ （iv）磁杆耦合如何影响材料的热传输和热力学特性？这些问题的答案提供了有关磁子和声子之间耦合的前所未有的知识，以及它们对范德华材料的热能的影响，这对于这些材料在旋转热量量和镁质旋转的应用中的应用至关重要。这项奖项反映了NSF的法定任务，并通过对基金会的智力进行了评估，以评估支持的criptiation和广泛的支持。

项目成果

Thermal Hall effect in a van der Waals triangular magnet FeCl2

范德瓦尔斯三角磁体 FeCl2 中的热霍尔效应

• DOI: 10.1103/physrevb.107.l060404
• 发表时间: 2023
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Xu, Chunqiang;Carnahan, Caitlin;Zhang, Heda;Sretenovic, Milos;Zhang, Pengpeng;Xiao, Di;Ke, Xianglin
• 通讯作者: Ke, Xianglin