Fluctuation, Correlation, and Order in Dense Quantum and Classical Systems

9319864 Ashcroft将在量子系统和经典系统中对涨落物理及其在电子和结构秩序中的表现进行理论研究。在实验的推动下，我们计划了三个研究重点：多体理论、相关经典系统和电子结构。在多体理论的基础上，利用相干态泛函积分方法建立了凝聚态物质的基本双组分理论。在相关的经典系统下，将发展出一种结构物质的理论，它与同质对应的理论平行。电子结构推力将通过单粒子和多体方法来检验在双费米子系统中明显存在快慢自由度的电子和质子密集集合中实验中看到的有序范围。所发展的理论将应用于高电流的问题，如超导性，准晶体和金属-绝缘体转变。理论研究将在相对简单的多体系统模型上进行，以便了解在秩序、结构和输运中产生的涨落物理。这项工作将为更复杂系统中的类似行为提供洞见。该研究不仅解决了凝聚态物理的基本问题，而且还将开发的模型应用于当前感兴趣的实际材料。* * *

9319864 Ashcroft Theoretical research will be conducted on fluctuational physics and its manifestations in electronic and structural order in both quantal and classical systems. Motivated by experiment, three research thrusts are planned: many-body theory, correlated classical systems, and electronic structure. Under many-body theory a fundamental two-component theory of condensed matter will be developed using coherent-state functional integral methods. Under correlated classical systems, a theory of structured matter will be developed which parallels the theory of the homogeneous counterpart. The electronic structure thrust will examine by both single-particle and many-body methods the range of orderings seen experimentally in dense assemblies of electrons and protons where fast and slow degrees of freedom in a dual fermion system are evident. The theories developed will be applied to problems of high current interest such as superconductivity, quasicrystals and the metal-insulator transition. %%% Theoretical research will be conducted on relatively simple models of many-body systems in order to gain an understanding of fluctuation physics as it arises in order, structure and transport. This work will provide insight into similar behavior in more complex systems. The research not only addresses fundamental issues in condensed matter physics, but also applies the models developed to real materials of current interest. ***