Magnetism of Quantum Spins Systems in Low Dimensions

低维量子自旋系统的磁性

• 批准号: 0305371
• 负责人: Mark Meisel
• 金额: --
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-15 至 2007-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0305371&HistoricalAwards=false
• 关键词: Magnetism; Quantum; Spins; Systems; Low

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.

这项研究涉及过渡金属配合物的磁性研究，其中金属自旋仅限于一维或二维空间维度（1D、2D）。 由于低维耦合，这些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，温度范围可低至 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 S=2 的线性链材料中，将绘制第一临界磁场的温度依赖性，并将其与理论和模拟研究进行比较，从而预测可能的新临界行为。 在二维中，将研究基于普鲁士蓝类似物的新型层状材料。 这些新系统的磁光切换温度低于 150 K。参与该项目的学生将学习广泛的现代实验技术，其中许多技术需要与实现超低温和极高磁场相关的技能。 该培训为工业界、学术界和政府部门的职业生涯提供了良好的准备。 该研究的主要影响是对基础物理学的影响，尽管涉及层状磁性材料的研究可能与信息存储行业具有一些技术相关性。该项目重点研究仅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，由于快速计算机的使用增加，现在可以使用新的分析和数值工具，因此它们的属性通常可以定性和定量地预测。 实验研究需要在极端低温和高磁场下进行研究。 这项工作对模型进行了严格的测试，并产生了与信息存储行业相关的见解。 参与的学生接受物理、化学和材料科学等跨学科领域的培训，为进入技术多元化的劳动力队伍做好充分准备。