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

9319864将对量子系统和经典系统中的涨落物理及其在电子和结构秩序中的表现进行阿什克罗夫特理论研究。在实验的推动下，计划进行三个研究推进：多体理论、关联经典系统和电子结构。在多体理论下，我们将用相干态泛函积分方法建立凝聚态的两分量基本理论。在关联的经典系统下，将发展出一种与均匀物质理论平行的结构物质理论。电子结构推力将用单粒子和多体方法研究实验中看到的电子和质子密集集合中的有序范围，其中双费米子系统中的快自由度和慢自由度是明显的。所发展的理论将应用于大电流问题，如超导、准晶和金属-绝缘体转变。将在相对简单的多体系统模型上进行理论研究，以了解涨落物理学在秩序、结构和输运方面的产生。这项工作将提供对更复杂系统中类似行为的洞察。这项研究不仅解决了凝聚态物理中的基本问题，还将所开发的模型应用于当前感兴趣的真实材料。***

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. ***