Quantum Critical Phenomena and Non-Fermi-Liquid Physics

0081075 MillisThis补助金支持一个杰出的，职业生涯中期PI的理论工作强相关电子系统。 该基金的研究项目包括（1）无序和量子临界现象，（2）高温超导性和（3）高度相关系统中的非平衡现象。 这类问题通常被称为非费米液体效应。 它们超越了朗道的费米液体理论对金属中电子的理解。 费米液体理论之外的异常包括稀土合金中大量的热力学/量热结果，这些结果被认为是由于无序而接近量子临界点。 在与高密度磁存储器和弛豫铁电体相关的材料中也存在相关效应。 高T_c铜氧化物存在非平衡效应，如高温电阻率。 该项目涉及分析和数值方法，沿着与相关实验工作的密切联系。该资助支持的理论工作来自当前材料研究的两个主题。 金属中电子的性质存在某些反常现象，这显然超出了传统的范式，即朗道的金属理论。 它们是由大量无序和/或极端环境如压力、磁场或温度的存在引起的。 这里的工作是根本性的和深远的，因为它可能需要开发复杂的，新的数学工具，同时它是由需要了解的材料，这是重要的高密度磁存储器或材料，利用其铁电性能的存储器应用的动机。 这项工作将与实验人员密切合作进行，并将在必要时利用分析和数字技术。

0081075MillisThis grant supports the theoretical work of a distinguished, mid-career PI on stronglyCorrelated electron systems. The list of research projects in this grant includes (1)Disorder and Quantum Critical Phenomena, (2) High Temperature Superconductivity and(3) Nonequilibrium phenomena in highly correlated systems. The class of problems hereis frequently referred to as non-Fermi liquid effects. They lie beyond the edge ofunderstanding of electrons in metals offered by Landau's Fermi liquid theory. Theanomalies beyond the Fermi liquid theory include the large number ofthermodynamic/calorimetric results in rare-earth alloys, which are believed to be near a quantum critical point due to disorder. There are related effects in materials relevant forhigh-density magnetic memories and in relaxor ferroelectrics. There are nonequilibriumeffects such as the high temperature resistivity of high Tc copper oxides. The projectsinvolve analytical and numerical approaches along with close contact with relevantexperimental work.%%%The theoretical work supported in this grant comes from two themes in current research on materials. There are certain anomalies in the properties of electrons in metals, whichApparently lie outside the conventional paradigm, referred to as the Landau's theory ofmetals. They are caused by the presence of substantial disorder and or extremeenvironmental such as pressure, magnetic field or temperature. The work here isfundamental and far-reaching in that it may require development of sophisticated, newmathematical tools and at the same time it is motivated by a need to understand materialswhich are important for high density magnetic memories or materials which use theirferroelectric properties for memory applications. This work will be carried out in closecontact with experimentalists and will make use of both analytical and numericaltechniques, as may be necessary.***