Stongly Correlated Electron Systems

9801751 Schlottmann这是对强关联电子系统理论研究的资助。 该奖项由材料研究部的材料理论计划和数学与物理科学理事会的多学科活动办公室资助。 国家科学基金会的拨款与能源部的类似拨款相协调。 本文从理论上研究了高关联电子，特别是重费米子系统、混合价磁氧化物、近藤绝缘体和一维导体的性质。 在重费米子中，主要的焦点是同时处理近藤屏蔽和格点间相互作用，重电子和一些重费米子化合物中观察到的微弱的反铁磁有序磁矩的巡游电子之间的关联的影响。 在锰杂质模型和一对锰离子的框架内研究了混合价锰离子的四极（Jahn-Teller）响应。 研究了近藤绝缘体差距中束缚态的起源以及自旋间隙和电荷间隙的差异。 所采用的方法是贝特安奈法、量子逆散射法和从玻色子方法。 这是对强关联电子系统理论研究的资助。 该奖项由材料研究部的材料理论计划和数学与物理科学理事会的多学科活动办公室资助。 国家科学基金会的拨款与能源部的类似拨款相协调。 将采取一些理论方法来研究强关联电子系统。 这些系统包括所谓的重费米子系统、混合价磁氧化物、近藤绝缘体和一维导体。 无论是要研究的系统和要使用的技术都处于现代凝聚态物理学的最前沿。 ***

9801751 Schlottmann This is a grant for theoretical research on strongly correlated electron systems. The award is funded by the Materials Theory Program in the Division of Materials Research and by the Office of Multidisciplinary Activities in the Mathematical and Physical Sciences Directorate. The NSF grant is coordinated with a similar one at DOE. Properties of highly correlated electrons, in particular, heavy fermion systems, mixed valent maganite compounds, Kondo insulators and one-dimensional conductors are studied theoretically. In heavy fermions the main focus is on the simultaneous treatment of Kondo screening and intersite interactions, effects of correlations among the itinerant electrons on the heavy electrons and the faint antiferromagneticallly ordered magnetic moments observed in some heavy-fermion compounds. The quadrupolar (Jahn-Teller) response of mixed valent manganese ions is studied within the framework of manganese impurity models and a pair of manganese ions. The origin of bound-states in the gap of Kondo insulators and the difference of spin and charge gaps are investigated. Methods employed are the Bethe Ansatz, the Quantum Inverse Scattering Method, and slave boson approaches. %%% This is a grant for theoretical research on strongly correlated electron systems. The award is funded by the Materials Theory Program in the Division of Materials Research and by the Office of Multidisciplinary Activities in the Mathematical and Physical Sciences Directorate. The NSF grant is coordinated with a similar one at DOE. A number of theoretical approaches will be taken to study strongly correlated electron systems. These systems include the so-called heavy fermion systems, mixed valent maganite compounds, Kondo insulators and one-dimensional conductors. Both the systems to be studied and the techniques to be used are at the forefront of modern condensed matter physics. ***