Collaborative Research: Understanding and Manipulating Magnetism and Spin Dynamics in Intercalated van der Waals Magnets

摘要：磁体在信息存储、能量收集、高速运输、水净化、生物医学等现代技术中发挥着至关重要的作用。商业设备通常利用三维磁铁，以块状晶体或纳米结构的形式，来实现所需的应用。本项目重点研究原子薄层二维磁性材料，由于其独特的低维特性和对外部刺激的高灵敏度，它比传统的三维磁铁具有显着的优势。该项目的目标是通过两位具有互补专业知识的主要研究人员的高度集成协作努力，了解和操纵一类新型二维磁铁的磁性。二维磁性的基本理解和动态控制有望为实现现代信息技术及其他领域的新型超紧凑设备铺平道路。通过该研究项目，主要研究人员将进一步努力培训学生，特别是少数族裔学生，以提高STEM研究的多样性。同时，计划开展互动外展活动，以促进贫困农村或郊区学校的STEM教育，并吸引高中生参与量子材料研究。技术摘要：二维磁体为奇异磁性的基础研究和先进技术的超紧凑设备创新提供了一个独特的平台。这个合作研究项目的首要目标是准确地绘制磁相图，并操纵自插层范德华磁体碲化铬的自旋动力学。实验工作包括：1)建立精确控制的插层-磁关系，绘制相图；2)调整和确定电荷载流子、插层磁矩和原子晶格间距对磁性能的相对影响；3)利用超快退磁、铁磁共振和太赫兹声子激发探测和操纵磁化和相干自旋动力学。该项目将在这个有趣的二维磁体家族中创建关于磁性和自旋动力学的系统和全面的知识。因此，该研究项目将为理解和设计二维嵌入磁性材料提供一个新的科学范式。与研究部分相关的是互动推广项目，旨在促进贫困农村或郊区学校的STEM教育，并通过将高中生与量子研究联系起来，激励他们。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。

Non-technical Abstract: Magnets play an essential role in modern technologies such as information storage, energy harvesting, high-speed transportation, water purification, and biomedicine. Commercial devices typically utilize three-dimensional magnets, in the form of bulk crystals or nanostructures, to realize the desired applications. This project focuses on atomically thin layers of two-dimensional magnetic materials, which have remarkable advantages over conventional three-dimensional magnets because of their exotic low-dimensional properties and high sensitivity to external stimuli. The goal of the project is to understand and manipulate the magnetic properties of a novel class of two-dimensional magnets through a highly integrated collaborative effort of two principal investigators with complementary expertise. The fundamental understanding and dynamic control of two-dimensional magnetism is anticipated to pave the way towards the realization of novel ultra-compact devices for modern information technology and beyond. Through the research project, the principal investigators will further their ongoing effort of training students, especially underrepresented minorities, to enhance diversity in STEM research. Meanwhile, interactive outreach activities are planned to promote STEM education in disadvantaged rural or suburban schools and to attract high school students to quantum materials research.Technical Abstract: Two-dimensional magnets offer a unique platform for both the fundamental study of exotic magnetism and the innovation of ultra-compact devices for advanced technologies. The overarching goal of this collaborative research project is to accurately map the magnetic phase diagram and manipulate spin dynamics in a family of self-intercalated van der Waals magnets, chromium tellurides. The experimental activities include: 1) establish precisely controlled intercalation-magnetism relations and create a phase diagram; 2) tuning and determining the relative influence of charge carriers, magnetic moments of intercalants, and atomic lattice spacing on the magnetic properties; 3) probing and manipulating the magnetization and coherent spin dynamics with ultrafast demagnetization, ferromagnetic resonance, and terahertz phonon excitation. The project will create systematic and comprehensive knowledge about magnetism and spin dynamics in this intriguing family of two-dimensional magnets. As such, the research project will offer a new scientific paradigm to understand and engineer two-dimensional intercalated magnetic materials. Correlated with the research components are interactive outreach programs that aim to foster STEM education in disadvantaged rural or suburban schools and inspire high school students by connecting them to quantum research.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.