Rare Earth Geometrically Frustrated Magnets

****技术****这项研究计划的目标是研究稀土几何挫折磁铁。在这些材料中，由于磁性亚晶格的特殊几何形状，与稀土离子相关的矩之间的相互作用相互竞争。这些材料中的挫折导致了不寻常的低温状态，在这种状态下，相互作用能量不能同时最小化，例如自旋液体和自旋冰。该研究将探索新的几何挫折磁性材料，并将特别关注自旋冰态，其中奇异的单极类激发已被观察到。这些实验将集中在磁化率研究上，但也将包括一些其他技术。这项研究将与材料科学家和化学家密切合作，他们可以提供独特和重要的新材料样品。参与研究的学生将参加传统和尖端的培训，包括广泛的实验技术，为他们在学术界、工业界或政府的职业生涯做好准备。****非技术****这是一个研究项目，研究一组被称为稀土几何挫折磁铁的材料的物理学。这些材料中的磁性原子无法以一种独特的方式指导它们的磁轴（称为磁矩），以最小化它们集体状态的组合能量。这种无法将能量最小化的根本原因是材料中磁性原子的几何排列，这种几何排列使这些材料成为广泛的其他复杂系统的优秀模型，这些系统同样“受挫”。特别是，这个研究项目将探索被称为自旋冰的特殊材料的性质，其中磁矩的无序模仿了冻结水的行为，并作为一个理想的模型系统，用于测试对许多其他系统的集体行为的基本理解。本研究还将探索本课程中其他通过取代化学式中不同元素获得的新材料，寻找它们经常表现出的各种新行为。了解这些磁性材料对其他系统如超导结阵列和玻璃都有意义，也可能为计算算法提供见解。首席研究员在研究过程的每个阶段都与不同的学生合作，并与研究生和本科生合作。参与该研究项目的学生将参加传统和尖端的培训，包括广泛的实验技术，为他们在学术界、工业界或政府的职业生涯做好准备。

****Technical**** The goal of this research program is to investigate rare earth geometrically frustrated magnets. These are materials in which the interactions between the moments associated with rare earth ions compete with each other due to the particular geometry of the magnetic sublattice. The frustration in these materials leads to unusual low temperature states in which the interaction energies cannot all be simultaneously minimized, such as spin liquids and spin ices. The research will explore new geometrically frustrated magnetic materials and will have a special focus on the spin ice states in which exotic monopole-like excitations have been observed. The experiments will focus on magnetic susceptibility studies but will also include a number of other techniques. The research will be conducted in close collaboration with material scientists and chemists who can provide unique and important samples of new materials. Students involved in the research will participate in traditional and cutting edge training in a wide range of experimental techniques that will prepare them for careers in academe, industry or government.****Non-technical****This is a research program into the physics of a group of materials known as rare earth geometrically frustrated magnets. The magnetic atoms in these materials are unable to direct their magnetic axes (known as the magnetic moments) in a unique way to minimize the combined energy of their collective state. The underlying cause of this inability to minimize the energy is the geometrical arrangement of the magnetic atoms within the materials, and this geometrical arrangement makes these materials excellent models for a wide range of other complex systems which are similarly 'frustrated'. In particular, this research program will probe the nature of special materials known as spin ices, in which the disorder of the magnetic moments mimics the behavior of frozen water and acts as an ideal model system for testing basic understanding of collective behavior of many other systems. The research will also probe other new materials in this class obtained through substituting different elements in the chemical formulae, and looking for various novel behavior that they often exhibit. Understanding these magnetic materials has implications for other systems as diverse as superconducting junction arrays and glasses, and may also provide insight into computational algorithms. The principal investigator has an extensive record of working with a diverse students and involving graduate students and undergraduates in every stage of the research process. Students involved in this research program will participate in traditional and cutting edge training in a wide range of experimental techniques that will prepare them for careers in academe, industry or government.