Theoretical Solid State Physics

理论固体物理

• 批准号: 1508412
• 负责人: Marvin Cohen
• 金额: $ 140万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2020-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1508412&HistoricalAwards=false
• 关键词: Theoretical; Solid; State; Physics

Nontechnical Description: This project supports theoretical and computational research and education on condensed matter physics and materials science. The fascinating properties and phenomena of condensed matter emerge from mutual interactions of the electrons and ions that constitute the material, many of which are central to modern technologies such as electronics, optoelectronics, and energy conversion devices. Often these properties are dramatically altered or new phenomena emerge from varying the chemical composition or confining the materials to nanometer scales. This project is centered on using quantum theory, modeling, and simulations to explain and predict novel materials and nanostructures. New theoretical approaches and the availability of modern massively parallel computers allow the team to obtain first-principles (i.e., with no empirical parameters) explanations and predictions of the behavior of atomically thin materials, nanostructures, interfacial and defect phenomena, new superconductors, and photocatalytic materials. The educational components are focused on training of graduate students and postdoctoral fellows for research and development in using materials in the current technological revolution. The research findings are published in scientific journals as well as presented on the team's website. The computational tools developed from the project are incorporated into several software packages - Berkeley GW, PARATEC, and EPW - which are made freely available on the web to the research community. Another educational activity is related to public education, which is done through articles and interviews published in lay media and via public lectures.Technical Description: This project aims at understanding the electronic and optical properties of materials and nanostructures at the microscopic level by performing first-principles quantum calculations. Topics investigated include: two-dimensional (2D) crystals such as graphene and transition metal dichalcogenides; nanotubes and nanoribbons; electronic properties and photophysics of novel bulk (such as topological insulators) and reduced-dimensional systems; and superconductivity. Emphasis is placed on using realistic models, close collaborations with experimentalists, investigations and predictions of novel and useful materials, and development of new theoretical and computational approaches. Several different approaches are employed. The ab-initio pseudopotential method and total-energy techniques are applied within the density functional formalism to compute ground-state properties. Excited-state (spectroscopic) phenomena are investigated using a first-principle self-energy approach based on the GW approximation for quasiparticle excitations and an ab-initio interacting two-particle Green's function method based on the Bethe-Salpeter equation for optical excitations. Other studies rely on molecular dynamics and Monte Carlo simulations, dielectric function methods, BCS theory, and extensions of standard many-body theory. Augmentation of existing methods to deal with strong electron correlations is also employed.

非技术描述：该项目支持凝聚态物理和材料科学的理论和计算研究和教育。凝聚态物质的迷人特性和现象来自构成材料的电子和离子的相互作用，其中许多是现代技术的核心，如电子学，光电子学和能量转换设备。通常，这些性质会发生显着变化，或者由于改变化学成分或将材料限制在纳米尺度而出现新的现象。该项目的重点是使用量子理论，建模和模拟来解释和预测新材料和纳米结构。新的理论方法和现代大规模并行计算机的可用性使团队能够获得第一原理（即，没有经验参数）对原子薄材料、纳米结构、界面和缺陷现象、新超导体和光催化材料的行为的解释和预测。教育部分的重点是培训研究生和博士后研究员在当前技术革命中使用材料进行研究和开发。研究结果发表在科学期刊上，并在该团队的网站上发表。从该项目开发的计算工具被纳入几个软件包-伯克利GW，PARATEC和EPW -这是免费提供给研究社区的网络。另一项教育活动与公众教育有关，通过在非专业媒体上发表文章和采访以及公开讲座进行。技术说明：本项目旨在通过第一性原理量子计算，在微观水平上理解材料和纳米结构的电子和光学性质。调查的主题包括：二维（2D）晶体，例如石墨烯和过渡金属二硫属化物;纳米管和纳米带;新型体（例如拓扑绝缘体）和降维系统的电子性质和电子物理学;以及超导性。重点放在使用现实的模型，与实验学家，调查和预测的新的和有用的材料，以及新的理论和计算方法的发展密切合作。采用了几种不同的方法。在密度泛函理论框架内，采用从头算赝势方法和总能量技术计算基态性质。激发态（光谱）的现象进行了研究，使用第一原理自能方法的基础上的GW近似的准粒子激发和从头算相互作用的两粒子绿色的功能方法的基础上的Bethe-Salpeter方程的光激发。其他研究依赖于分子动力学和蒙特卡罗模拟，介电函数方法，BCS理论和标准多体理论的扩展。增强现有的方法来处理强电子相关性。