RUI-TAILORING LOW-DIMENSIONAL QUANTUM MAGNETS TO EXPLORE PHASE DIAGRAMS AND CRITICAL POINTS

****非技术摘要****量子磁体是化学、物理和材料科学的一个重要研究领域。这些材料的相图可以从一系列参数中推导出来，每一个参数都告诉我们一些关于电子如何相互作用以及它们的环境的信息。调节参数空间的能力对于开发具有潜在社会效益的新材料至关重要。该项目由材料研究部固态与材料化学项目和凝聚态物理项目资助，旨在创建具有不同空间维度（即1D， 2D或3D）的建筑，以将目标材料放置在这些关键区域附近。在那里，电子会发生奇怪的事情；例如，理论预测，超导和其他状态的物质可能出现作为这些特性的结果。为了操纵我们材料的磁性，研究人员使用了化学手段，高压和高磁场。这个高度协作的项目涉及多个国家和国际用户设施。这为本科生提供了独特的机会，可以与主要研究者一起旅行，参加许多计划中的实验以及参加专业会议。学生参与项目的每一个方面都激发了他们作为年轻科学家的成长和热情，并为将来开始研究生工作或继续从事化学和物理科学的职业提供了动力。指导和培训本科生是这个项目的重中之重。****技术摘要****固体提供了许多模型量子系统的例子，然而，无序的作用和原子尺度化学的细节阻碍了我们以任何系统的方式控制关键参数的能力。该项目由材料研究部固态与材料化学项目和凝聚态物理项目资助，假设开发可调量子模拟器的关键是识别合适的分子系统。事实上，金属有机磁体是一种材料，其主要结构构建块包含量子成分（S = 1/ 2,1或3/2基态的过渡金属离子），通过柔性和高度可调的有机框架耦合。因此，研究人员通过化学设计来调整这些系统，以便：(a)它们形成能够在明确定义的拓扑结构中促进磁交换的结构；(b)修改了所选磁单元之间的单离子各向异性和相互作用强度。该项目的核心是利用化学手段、静水压力和强磁场将真实材料调整到相边界和量子临界点（QCP），从而系统地探索相图。来自各种背景的本科生进行合成并协助数据分析和样品表征，前往最先进的研究设施，并参加/在专业会议上展示他们的工作。学生参与项目的每一个方面都激发了他们作为年轻科学家的成长和热情，并为将来开始研究生工作或继续从事化学和物理科学的职业提供了动力。指导和培训本科生是这个项目的重中之重。

****NON-TECHNICAL ABSTRACT****Quantum magnets constitute a major research area in chemistry, physics and materials science. The phase diagrams of such materials can be derived for a range of parameters, each of which tells us something about how electrons interact with each other and their environment. An ability to tune the parameter space is crucial to developing new materials of potential benefit to society. This project, funded by the Solid State and Materials Chemistry Program and the Condensed Matter Physics Program in the Division of Materials Research, targets the creation of architectures with varying spatial dimensionality (i.e., 1D, 2D, or 3D) to place targeted materials near these critical regions. Therein, strange things can happen to electrons; for example, theory predicts that superconductivity and other states of matter may emerge as a result of these peculiarities. To manipulate the magnetic properties of our materials, the researchers employ chemical means, high-pressure, and high magnetic fields. The highly collaborative project involves several national and international user facilities. This provides unique opportunities for undergraduate students to travel with the principal investigator to partake in many of the planned experiments as well as to attend professional conferences. Student involvement in every aspect of the project stimulates their growth and enthusiasm as young scientists as well as provide the impetus to begin graduate work in the future or to go on to careers in the chemical and physical sciences. Mentorship and training of undergraduate students is a high priority of this project.****TECHNICAL ABSTRACT****The solid state provides many examples of model quantum systems however, the role of disorder and the details of atomic-scale chemistry hinder our ability to control crucial parameters in any systematic way. This project, funded by the Solid State and Materials Chemistry Program and the Condensed Matter Physics Program in the Division of Materials Research, hypothesizes that the key to developing a tunable quantum simulator is to identify appropriate molecular systems. Indeed, metal-organic magnets are materials whose primary structural building blocks embody a quantum component (a transition metal ion with S = 1/2, 1 or 3/2 ground state) coupled through a flexible and highly tunable organic framework. Therefore, studies are carried out to tune these systems via chemical design so that (a) they form structures able to promote magnetic exchange in well-defined topologies; and (b) the single-ion anisotropy and strength of interactions between the chosen magnetic units is modified. Systematic exploration of phase diagrams by tuning real materials toward phase boundaries and quantum critical points (QCP) using chemical means, hydrostatic pressure, and high magnetic fields is at the core of this project. Undergraduate students, from all backgrounds, carry out the syntheses and assist with data analysis and characterization of samples, travel to state-of-the-art research facilities, and attend/present their work at professional conferences. Student involvement in every aspect of the project stimulates their growth and enthusiasm as young scientists as well as provide the impetus to begin graduate work in the future or to go on to careers in the chemical and physical sciences. Mentorship and training of undergraduates is a high priority of this project.