Physics of Magnetic Impurities in Metals

9316587英格森这项建议涉及嵌入在非磁性材料中的磁性杂质之间的相互作用所产生的物理问题。具体地说，需要研究多波段Kondo和Anderson模型的行为。在多带Kondo和Anderson模型中观察到了边际费米-液体行为(高T_c材料的正常态)，但最近的数值重整化群计算表明，当允许杂质之间的相互作用时，费米-液体行为被恢复。PI建议将这项工作扩展到更复杂和/或更现实的模型，以及耦合到多个带的受挫磁系统。这项工作涉及阐明一些模型的行为，这些模型被用来描述含有重磁性元素的材料的电学性质，例如最近发现的高温超导体。这里的讨论围绕着这种材料的电子态的适当的零级描述是什么。一些假定的模型，最简单地说，给出了某些类型的不寻常行为，但PI已经表明，随着这些模型变得更加“现实”，那么行为往往会回归到传统固态物理学更熟悉的更常见的描述。PI将继续这项工作，朝着更加现实的描述前进。***

9316587 Ingersent This proposal concerns the physics arising out of interactions between magnetic impurities embedded in non-magnetic materials. Specifically, the behavior of multi-band Kondo and Anderson models are to be studied. Marginal-Fermi-liquid behavior (a suggestion for the normal state of the high Tc materials) is observed for multi- band Kondo and Anderson models, but recent numerical renormalization-group calculations show that when interaction is allowed between impurities, Fermi-liquid behavior is recovered. The PI proposes to expand this work to more complex and/or realistic models and to frustrated magnetic systems coupled to multiple bands. %%% This work concerns elucidation of the behavior of models which have been put forward to describe the electronic properties of materials containing heavy magnetic elements such as the recently discovered high temperature superconductors. Discussion here has revolved around what is the appropriate zeroth order description of the electronic states of such materials. Some of the putative models, at their simplest give certain types of unusual behaviors but the PI has shown that as these models are made more "realistic", then behavior tends to revert to the more usual descriptions with which traditional solid state physics is more familiar. The PI will continue this work towards ever more realistic descriptions. ***