Magnetism of Quantum Spins Systems in Low Dimensions

本研究涉及过渡金属配合物的磁性研究，其中金属自旋被限制在一个或两个空间维度（1D，2D）。 由于低维耦合，材料表现出有趣的磁相图作为温度，磁场和压力的函数。 相行为将通过一系列实验技术进行研究，其中包括磁化率和比热测量，温度低至50毫开尔文，场强高达9特斯拉。 这些热力学研究补充了光学和磁共振光谱研究。 在一个S=2的线性链材料中，第一临界磁场的温度依赖性将被映射，并与理论和模拟研究进行比较，预测可能的新临界行为。 在二维空间中，基于普鲁士蓝类似物的新型层状材料将被研究。 这些新系统在150 K以下实现了磁光开关。 参加该项目的学生将学习广泛的现代实验技术，其中许多需要与实现超低温和非常高的磁场相关的技能。 这种培训为工业，企业和政府的职业生涯提供了良好的准备。 该研究的主要影响是在基础物理学上，尽管涉及层状磁性材料的研究可能与信息存储行业有一些技术相关性。该项目侧重于研究局限于一维或二维空间的新型磁性系统。 低维系统的一个引人注目的方面是，它们的性质往往是定性和定量预测，因为新的分析和数值工具，现在由于快速计算机的访问增加。 实验研究需要在低温和高磁场的极端情况下进行研究。 这项工作提出了严格的测试模型，并产生相关的信息存储行业的见解。 参与的学生接受各种跨学科领域的培训，即物理，化学和材料科学，并为进入技术多样化的劳动力做好充分准备。

This research involves the study of the magnetic properties of transition metal complexes in which the metal spins confined to one or two spatial dimensions (1D, 2D). Because of the low-dimensional couplings, the materials exhibit interesting magnetic phase diagrams as a function of temperature, magnetic field, and pressure. The phase behavior will be investigated by a range of experimental techniques, which include susceptibility and specific heat measurements that extend to temperatures as low as 50 millikelvin and field strengths up to 9 Tesla. These thermodynamic studies complement optical and magnetic resonance spectroscopy investigations. In one linear-chain material with S=2, the temperature dependence of the first critical magnetic field will be mapped and compared with theory and simulation studies, which predict possible new critical behavior. In two dimensions, novel layered materials based upon Prussian blue analogues will be investigated. These new systems are magneto-optically switched below 150 K. Students participating in the project will learn a wide range of modern experimental techniques, many of which require skills associated with attaining ultra low temperatures and very high magnetic fields. This training provides excellent preparation for careers in industry, academe and government. The primary impact of the research is on fundamental physics, though the research dealing with layered magnetic materials may have some technological relevance to the information storage industry.This project focuses on the investigation of novel magnetic systems confined to one or two spatial dimensions. A striking aspect of low dimensional systems is that their properties are often qualitatively and quantitatively predictable since new analytical and numerical tools are now available due to increased access to fast computers. The experimental research requires investigations at the extremes of low temperatures and high magnetic fields. The work presents stringent tests of the models and yields insight relevant to the information storage industry. The participating students receive training in a variety of interdisciplinary fields, namely physics, chemistry, and materials science, and are well prepared to enter the technologically diverse work force.