CAREER: Manipulation of Quantum Materials Through Strain

人类社会的进步与材料的发现、理解和应用密切相关。纵观历史，时代已经根据材料进行了分类，如石器时代，青铜时代和铁器时代。当今时代正处于硅时代的边缘，其特征是半导体产业的快速增长。然而，一种被称为量子材料的新材料正在出现，并且注定会像硅一样为人所熟悉。这些材料对量子计算机等未来技术至关重要，它们在各种能量和长度尺度上表现出量子效应，从而产生独特的特性。尽管它们具有潜力，但对量子材料的理解仍然有限。该研究项目围绕通过单轴压力操纵量子材料来探索各种“涌现”现象。这种方法旨在增强对晶格如何影响量子材料中相关性的理解，这是材料科学的一个基本而关键的方面。通过综合教育和推广工作，该项目通过尖端量子材料研究将学生培养为下一代科学领导者。与自然历史博物馆和密歇根大学科学与工程领域的妇女合作，使公众，特别是科学领域代表性不足的群体能够有效参与。因此，该研究项目不仅旨在推动量子材料的知识边界，还旨在激励和授权多样化的科学家社区，为科学和技术的进步做出重大贡献。技术摘要：基础物理研究中的一个主要问题是如何理解不能被视为非相互作用粒子的相互作用量子对象的集体行为。在凝聚态物理学中，由大量原子组成的物质系统可以通过周期势和库仑相互作用来简化。然而，这种最简单的模型往往无法捕捉交互的真实本质。或者，人们可以探索“涌现”现象。具体而言，以强多体相互作用为特征的复杂量子材料为研究迷人的现象提供了理想的平台。此外，四个基本自由度-晶格，电荷，轨道和自旋-提供了广泛的可调性的异国情调的属性，导致丰富的相图相关系统。对材料施加应力代表了一种操纵其四个基本自由度和对称性的新方法，不受原子替换引起的复杂性的影响。该研究项目旨在通过使用最近开发的现代单轴应力设备探测电子结构变化来促进对量子材料中相关行为的理解。本论文的主要工作包括四个方面：1）研究重费米子系统中的应变效应对轨道混合的影响。2)通过各向异性2D磁体中的应变操纵来控制磁性。3)量子材料中应变诱导的涌现现象的解析。4)发现具有灵敏应变调谐潜力的新相关材料。这些研究项目代表了增强量子材料理解和探索其在各个领域的潜在应用的有希望的途径。该奖项反映了NSF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而被认为值得支持。

Non-technical abstract: The advancement of human society is closely linked to the discovery, understanding, and application of materials. Throughout history, epochs have been categorized based on the materials, such as the stone age, bronze age, and iron age. Current era stands on the edge of the silicon age, characterized by the rapid growth of the semiconductor industry. However, a new category of materials, known as quantum materials, is emerging and is destined to become as familiar as silicon. These materials, crucial for future technologies like quantum computers, exhibit quantum effects across various energy and length scales, resulting in unique properties. Despite their potential, understanding of quantum materials remains limited. This research project is centered around the manipulation of quantum materials through uniaxial pressure to explore various 'emergent' phenomena. This approach aims to enhance the understanding of how the lattice influences the correlation in quantum materials, a fundamental yet crucial aspect of material science. Through integrated education and outreach efforts, this project trains students as the next generation of leaders in science through cutting-edge quantum materials research. Collaborations with the Museum of Natural History and Women in Science and Engineering at the University of Michigan enable effective engagement with the public and particularly underrepresented groups in science. As a result, this research project not only aims to push the boundaries of knowledge in quantum materials but also seeks to inspire and empower a diverse community of scientists, making significant contributions to the advancement of science and technology.Technical abstract: A major question in basic physical research is how to understand the collective behavior of interacting quantum objects that cannot be treated as non-interacting particles. In condensed matter physics, material systems consisting of numerous atoms, can be simplified by periodic potentials and Coulomb interactions. However, this simplest model often fails to capture the true nature of interactions. Alternatively, one can explore 'emergent' phenomena. Specifically, complex quantum materials, characterized by strong many-body interactions, offer an ideal platform to investigate fascinating phenomena. Additionally, the four fundamental degrees of freedom—lattice, charge, orbital, and spin—provide extensive tunability of exotic properties, leading to rich phase diagrams for correlated systems. Applying stress to a material represents a novel approach to manipulating its four fundamental degrees of freedom and symmetry, free from complexities arising from atomic substitutions. This research project aims to advance the understanding of correlated behaviors in quantum materials by probing electronic structure changes using recently developed modern uniaxial stress devices. The proposed research is organized into four key thrusts: 1) Investigating the strain effect on orbital mixing in a heavy fermion system. 2) Controlling magnetism through strain manipulation in an anisotropic 2D magnet. 3) Unraveling strain-induced emergent phenomena in quantum materials. 4) Discovering new correlated materials with potential for sensitive strain tuning. These research projects represent promising avenues for enhancing the comprehension of quantum materials and exploring their potential applications across various fields.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.