Spin fluctuations in itinerant electron systems

流动电子系统中的自旋涨落

• 批准号: 1506704
• 负责人: Emilia Morosan
• 金额: $ 44.07万
• 依托单位: William Marsh Rice University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-15 至 2019-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1506704&HistoricalAwards=false
• 关键词: Spin; fluctuations; itinerant; electron; systems

NON-TECHNICAL ABSTRACT: While a century old problem, magnetism remains poorly understood. Of the two extreme magnetic states - those with magnetic moments localized in small spatial volumes (local moments) and those shared by the entire compound (itinerant moments), the former remains better described theoretically, with most real materials actually residing in the continuum between the two. The main goal of this project is to discover and characterize novel itinerant magnets without magnetic elements. It is of particular interest to understand what happens as the temperature is lowered close to absolute zero, or towards quantum phase transitions (QPT), fundamentally distinct transitions compared to the more familiar phase transitions, for example liquid-to-solid. Exotic physics is believed to emerge from QPTs and these will be studied with tuning parameters such as composition, pressure or magnetic field. Undergraduate and graduate students involved in the project will be trained in crystal growth and characterization, valuable tools for materials driven condensed matter research. The PI will develop a class on scientific presentation skills, and will establish two series of lab open houses, for hands-on experience for children and for adults.TECHNICAL ABSTRACT: This NSF award supports experimental investigations and education in condensed matter physics, with focus on novel magnetic states of matter in the itinerant moment regime. In particular, the goal of this proposal is to investigate novel itinerant magnets containing no magnetic elements, where the the chemical tunability of the only three known such magnetic systems will be explored towards designing the new compounds of interest. The main thrusts of the project are studies of (i) the correlations between the structural and physical properties of itinerant electron magnets, (ii) the interplay between electronic and magnetic ground states and (iii) non-Fermi liquid behavior in itinerant magnet systems. In addition, the recently discovered hardness of some related alloys will be investigated and the materials optimized for medical and possibly new technological applications. The PI will develop a class on scientific presentation skills, and will establish two series of lab open houses, for hands-on experience for children and for adults.

非技术摘要：虽然一个世纪的问题，但磁性仍然很少理解。在这两个极端磁性状态下，具有磁矩的磁力量（局部矩）以及由整个化合物（巡回力矩）共享的磁矩，前者在理论上保持更好地描述，实际上大多数真实的材料实际上位于两者之间的连续体中。该项目的主要目标是发现并表征没有磁性元素的新型巡回磁铁。与更熟悉的相变相比（例如液体向固体），了解温度接近绝对零或朝量子相变（QPT）的降低或朝向量子相变（QPT）（例如液体向固体）而言，这是特别有趣的。人们认为外来物理学是从QPT中出现的，这些物理学将通过调整参数（例如组成，压力或磁场）进行研究。参与该项目的本科生和研究生将接受晶体增长和表征，材料驱动的冷凝物质研究的宝贵工具的培训。 PI将开发有关科学演示技巧的课程，并将建立两个系列的实验室开放式房屋，以供儿童和成人进行动手体验。技术摘要：该NSF奖授予了凝聚态物理学的实验研究和教育，重点介绍了务必时刻制度中物质的新磁性状态。特别是，该提案的目的是研究包含磁性元素的新型巡回磁铁，其中将探索仅有的三个已知磁性系统的化学可调节性来设计新的感兴趣化合物。该项目的主要推力是对（i）巡回电子磁体的结构和物理性质之间的相关性，（ii）电子和磁接地状态之间的相互作用以及（iii）在流动磁铁系统中的非Fermi液体行为。此外，将研究最近发现的一些相关合金的硬度，并针对医疗和可能的新技术应用进行了优化的材料。 PI将开发有关科学演示技巧的课程，并将建立两个系列的实验室开放式房屋，以供儿童和成人实践经验。