Local Moment and Heavy Fermion Physics

局域矩和重费米子物理

• 批准号: 0907179
• 负责人: Piers Coleman
• 金额: $ 33万
• 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: 2009
• 资助国家: 美国
• 起止时间: 2009-09-15 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0907179&HistoricalAwards=false
• 关键词: Local; Moment; Heavy; Fermion; Physics

TECHNICAL SUMMARYThis award supports theoretical research and education on heavy electron materials and local moment physics. The new concepts required to understand these low-energy materials, will, in many cases scale up in energy and temperature to describe related phenomenon in transition Metal materials, such as copper and iron-based superconductors. Many of the key questions in this area touch upon issues of fundamental importance, such as the physics of quantum criticality, mechanisms of anisotropic superconductivity, and the origins of non-Fermi liquid behavior. Motivated by the discovery of two new and unusual heavy fermion superconductors, the PI will apply a new type of large-N expansion for heavy electron superconductivity that he has recently developed. Fresh insights in heavy electron quantum criticality and the discovery of a Kondo spin liquid material inspire the PI to embark on a new set of investigations into the phase diagram of the Kondo lattice. A magnetically tuned critical end point in a multiferroic oxide has recently been discovered. The PI will pursue a new research program to study field-tuned quantum criticality in multiferroic materials.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 materials of the future. For example, the remarkable tendency of quantum critical points to nucleate superconductivity and other 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 wonderful area for students to learn the advanced methods of theoretical physics, while maintaining an intimate contact with experimental physics and real materials.The PI is strongly committed to diversity in physics, with a long record of support for women in physics. Two women graduate students are currently working in his group. NON-TECHNICAL SUMMARYThis award supports theoretical research and education on a class of materials known as heavy electron materials. The interplay of electrons in itinerant quantum states and quantum states localized around a rare-earth or actinide atom leads to an unusual metallic state with properties that are consistent with the textbooks. The properties of these materials are further complicated by the existence of quantum phase transitions - phase transitions that occur at the absolute zero of temperature but with a powerful influence that can be felt over a range of temperature. The PI will build on and use a promising new method that he has developed to gain insight into two recently discovered materials in this class that are superconductors and into heavy electron materials more generally. The PI will also study the superconducting states of these materials. The PI will further explore the role quantum phase transitions play in newly discovered multiferroic materials which are a promising class of materials for future electronic devices. The study of the superconducting states and the unusual metallic states which give way to superconductivity contributes to the intellectual foundations of materials research and superconductivity. This knowledge may lead to harnessing the ability of superconductors to carry electric current with no to very low power dissipation in a practical way leading to significant energy savings. The PI is strongly committed to diversity in physics, with a long record of support for women in physics. Two women graduate students are currently working in his group.

技术摘要这一奖项支持有关重型电子材料和本地瞬间物理学的理论研究和教育。了解这些低能材料所需的新概念将在许多情况下扩大能量和温度，以描述过渡金属材料（例如铜和铁基超导体）中相关现象。该领域的许多关键问题都涉及基本重要性的问题，例如量子临界的物理学，各向异性超导性的机制以及非Fermi液体行为的起源。由于发现了两个新的和不寻常的重型费米昂超导体的动机，PI将对他最近开发的重型电子超导性进行新型的大N扩展。重型电子量子关键性的新见解以及发现近托旋转液体材料的发现激发了PI开始对Kondo晶格的相图进行新的研究。最近已经发现了多种氧化多氧化物中的磁性调谐临界终点。 PI将追求一项新的研究计划，以研究多效材料中的现场调整量子批判性。研究“硬冷凝物理学”的各个方面在新物理学概念的发展和未来材料的新思想中都起着重要的驱动作用。例如，量子临界点对超导性和物质的其他新阶段的显着趋势引起了材料发育的极大关注。另一方面，量子相变的新通用类别具有极大的基本兴趣，就像它们在统计力学中的经典前辈一样，也可能在宇宙学和粒子物理学领域中享有概括和未来的应用。这是学生学习理论物理学的先进方法的绝佳领域，同时与实验物理和真实材料保持亲密接触。PI强烈致力于物理学的多样性，并长期以来对物理女性的支持很长。目前有两名女研究生正在他的小组工作。非技术摘要这一奖项支持一类称为重型电子材料的材料的理论研究和教育。巡回量子状态和量子状态的电子相互作用围绕稀土或actinide原子定位，导致具有与教科书一致的特性的不寻常的金属状态。这些材料的特性因存在量子相变的存在而变得更加复杂 - 在温度的绝对零处发生，但具有强大的影响，可以在温度范围内感受到强大的影响。 PI将建立并使用一种有希望的新方法，他已经开发出来，以洞悉该类别是超导体的两种最近发现的材料，并更普遍地介绍了重型电子材料。 PI还将研究这些材料的超导状态。 PI将进一步探讨量子相变的作用，在新发现的多效材料中，这是未来电子设备的有前途的材料类别。对超导状态和非同寻常的金属状态的研究，使超导性取代超导性，这有助于材料研究和超导性的智力基础。这些知识可能导致利用超导体以实用的方式携带电流，而无需极低的功率耗散，从而导致大量节能。 PI强烈致力于物理多样性，并为物理女性提供了很长的记录。目前有两名女研究生正在他的小组工作。