Local Moment and Heavy Fermion Physics

局域矩和重费米子物理

• 批准号: 0605935
• 负责人: Piers Coleman
• 金额: $ 36.6万
• 依托单位: Rutgers University New Brunswick
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-01 至 2010-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0605935&HistoricalAwards=false
• 关键词: Local; Moment; Heavy; Fermion; Physics

This grant is for the support of the core condensed matter theory research and education activities of Piers Coleman, along with the participation of senior personnel collaborator, Professor Elihu Abrahams. Intellectual Merit: Heavy electron and local moment physics occupy a vital corner in current research into correlated electron materials. Many of the key questions touch upon issues of fundamental importance to the condensed matter community, such as the physics of quantum criticality, mechanisms of anisotropic superconductivity, and the origins of non-Fermi liquid behavior. This makes it an ideal training ground for students of condensed matter physics. The PI's recent success in applying the Schwinger boson to fully screened Kondo models opens up a unique opportunity to connect magnetism and heavy electron physics, an important component of this project. The recent discovery of the charge Kondo effect in doped PbTe, confirming a past prediction of the PI, motivates a new program to adapt tools and concepts from magnetism and spin physics to systems with preformed pairs and slow charge fluctuations. Lastly, the recent discovery of a two dimensional heavy fermion behavior in bilayer 3He, provides the motivation for a new study of heavy fermion behavior in two dimensions.Broader Impact: Research into the various aspects of "hard condensed matter physics" plays an essential driving role in both the development of new physics concepts, and new ideas for the development of materials of the future. For example, the remarkable tendency of quantum critical points to nucleate new phases of matter is of great interest to materials development; on the other hand, the new universality classes of quantum phase transition are of great fundamental interest and, like their classical predecessors in statistical mechanics, may enjoy generalization and future application in the realm of cosmology and particle physics. This is a great area for students to learn the advanced methods of theoretical physics, while maintaining an intimate contact with experimental physics and real materials. The work described in this proposal will contribute modestly to the growth of our understanding of correlated matter, helping the experimentalist to develop new probes and forging new conceptual frameworks that complement the older approaches of solid state physics.The PI aims to focus his studies on: quantum phase transitions in heavy electron systems; transport and electrodynamics of valence skipping materials; heavy fermion physics in two dimensional bilayer 3He on graphite; and superconductivity in the layered 115 materials.Non-Technical Abstract: This grant supports theoretical research and education in condensed matter physics. The research is fundamental and has high intellectual merit in that the results will advance the progress of condensed matter physics and also may influence other fields of physics. Novel phenomena discovered in these systems may lead to materials for future devices. The project includes the participation of students and postdoctoral associates. The principal investigator is an effective spokesman for condensed matter physics both within this community and with the general public.The research will focus on the behavior of electrons in special classes of materials in which they behave as if their mass is many times their real mass. Hence these materials are called heavy electron materials. These "heavy electrons" are intricately connected with the superconducting, magnetic and electronic properties of theses materials. Trying to understand their behavior presents many intellectual challenges, yields many surprises, and lays the foundations for understanding how the interactions among electrons in a material can lead to new phenomena.

这项资助是为了支持Piers Coleman的核心凝聚态理论研究和教育活动，以及高级人事合作者Elihu Abrahams教授的参与。智力优势：重电子和局部矩物理在当前相关电子材料的研究中占有重要地位。许多关键问题涉及对凝聚态物质界具有根本重要性的问题，例如量子临界物理学、各向异性超导机制和非费米液体行为的起源。这使它成为凝聚态物理学生的理想训练基地。PI最近成功地将Schwinger玻色子应用于全面筛选的近藤模型，这为将磁性和重电子物理联系起来提供了一个独特的机会，这是该项目的一个重要组成部分。最近在掺杂PbTe中发现了电荷近藤效应，证实了过去对PI的预测，激发了一个新的项目，将磁学和自旋物理学的工具和概念应用于预制对和慢电荷波动的系统。最后，最近在双层3He中二维重费米子行为的发现，为二维重费米子行为的新研究提供了动力。更广泛的影响：对“硬凝聚态物理”各个方面的研究对于新物理概念的发展和未来材料发展的新思路都起着至关重要的推动作用。例如，量子临界点形成物质新相的显著趋势对材料的发展具有极大的兴趣；另一方面，量子相变的新普适性类具有重大的基础意义，并且像它们在统计力学中的经典前辈一样，可能在宇宙学和粒子物理学领域得到推广和未来的应用。这是学生既能学习到理论物理的先进方法，又能与实验物理和真实材料保持密切接触的好地方。本提案中所描述的工作将适度地促进我们对相关物质的理解，帮助实验学家开发新的探针，并形成新的概念框架，以补充固态物理的旧方法。PI的主要研究方向是：重电子系统中的量子相变；跳价物质的输运及电动力学研究石墨上二维双层3He中的重费米子物理以及层状115材料的超导性。摘要：本基金支持凝聚态物理的理论研究和教育。该研究具有基础性和高智力价值，其成果将推动凝聚态物理学的发展，并可能影响物理学的其他领域。在这些系统中发现的新现象可能会导致未来设备的材料。该项目包括学生和博士后助理的参与。首席研究员是凝聚态物理学的有效发言人，无论是在这个社区还是在公众面前。这项研究将集中在特殊材料中电子的行为上，在这些材料中，电子的行为就好像它们的质量是它们实际质量的许多倍。因此这些材料被称为重电子材料。这些“重电子”与这些材料的超导、磁性和电子特性有着错综复杂的联系。试图理解它们的行为提出了许多智力挑战，产生了许多惊喜，并为理解材料中电子之间的相互作用如何导致新现象奠定了基础。