Bad Metal Behavior and the Metal-Insulator Transition

非技术总结该奖项支持有关材料的理论和计算研究和教育，这些材料的性能介于典型金属和绝缘体之间。这些奇怪的“坏”金属具有令人惊讶的高电阻和不同寻常的热性能。对于属于这一制度的材料，材料中电子的动力学发生了戏剧性的变化：它们放慢了速度，这反过来又产生了电子在穿过固体时探索的势能格局的所有关键特征的根本改变。这个政权究竟发生了什么，长期以来一直是一个基本的科学谜题；现在，由于最近的进展，新的见解即将到来。过去几年发生的更现实的微观建模和新的实验能力正在打开令人兴奋的新的研究机会，在这个项目中利用这些机会来了解这些材料行为的基本方面。这个项目还将包括对研究生进行理论和计算凝聚态物理的培训。该局会继续透过各项外展活动，向公众推广和加强对科学技术的广泛认识，以及基础研究的重要性。这些活动将包括：1)在小学进行演讲，以普及科学技术，并将最新的科学发现带给年轻学生；2)在该地区公立和私立学校的K-12学生参加的年度地区性科学博览会上担任评委；3)与高中暑期实习生合作，作为“佛罗里达青年学者”计划的一部分，使他们能够通过开发Java动画和其他基于网络的材料，将尖端科学带给广大公众。TECHNICAL SUMMARY该奖项支持介于金属和绝缘体之间的材料的理论和计算研究与教育。这种金属和绝缘体之间的所谓“不良金属”状态的典型特征是其行为与任何一种状态都有本质上的不同。PI将从理论上研究由于最近的实验发现而成为焦点的金属-绝缘体转变(MIT)区域的几个基本方面，这将归功于新一代理论工具：1)将为半导体表面上的新型离子系统开发第一性原理建模，从而能够通过纳米级控制和成像来探索掺杂半导体中的MIT。2)将探索通过快速过冷获得的物质的亚稳相，这些相通常表现为无定形或非常规周期形式的电子有序。3)将在通过无序驱动的MITs调谐的系统中研究电子-电子和电子-声子相互作用的显著增加的作用，解决Mooij关联和相关的电阻率饱和的长期难题。该项目还将包括对研究生进行理论和计算凝聚态物理的培训。该局会继续透过各项外展活动，向公众推广和加强对科学技术的广泛认识，以及基础研究的重要性。这将包括：1)在小学讲课，以普及科学技术，并使年轻学生能够接触到最新的科学发现；2)在区域内公立和私立学校的K-12学生参加的年度区域科学博览会上担任评委；3)作为“佛罗里达青年学者”计划的一部分，与高中暑期实习生合作，使他们能够通过开发Java动画和其他基于网络的材料，将尖端科学带给广大公众。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

NONTECHNICAL SUMMARYThis award supports theoretical and computational research and education on materials that exhibit properties that fall somewhere between those of typical metals and insulators. These curious "bad" metals have surprisingly high resistance and unusual thermal properties. For materials that fall within this regime, the dynamics of electrons in the material change dramatically: they slow down, and this in turn produces essential modifications of all key features of the potential energy landscape that an electron explores on its way through the solid. What precisely happens in this regime has long presented a basic science puzzle; now, due to recent progress, new insight is at hand. More realistic microscopic modeling and new experimental capabilities that have occurred in the last few years are opening exciting new research opportunities that are exploited in this project to understand fundamental aspects of the behavior of these materials.This project will also involve training of graduate students in theoretical and computational condensed matter physics. The PI will continue to promote and enhance broad scientific and technological understanding and the importance of fundamental research to the general public through various outreach activities. These will include: 1) Presenting lectures at elementary schools in order to popularize science and technology and to bring recent scientific discoveries within reach of young students; 2) Serving as a judge at annual regional Science Fairs that involve K-12 students from public and private schools within the region; 3) Working with high-school summer interns as a part of the "Florida Young Scholar" program, enabling them to bring cutting-edge science to the public at large through the development of JAVA animations and other web-based materials.TECHNICAL SUMMARYThis award supports theoretical and computational research and education on materials that fall somewhere between metals and insulators. This so-called "bad metal" regime between a metal and an insulator is typically characterized by behavior that is qualitatively different from either phase. The PI will theoretically examine several fundamental aspects of the metal-insulator transition (MIT) region that have come into focus due to very recent experimental discoveries, which will be possible thanks to a newer generation of theoretical tools: 1) First-principles modeling will be developed for novel ionic systems on semiconductor surfaces, allowing to explore the MIT in doped semiconductors with nanoscale control and imaging. 2) Metastable phases of matter that are obtained by rapid supercooling will be explored, which often display amorphous or unconventional periodic forms of electronic order. 3) The dramatically increased role of electron-electron and electron-phonon interactions will be investigated in systems tuned through disorder-driven MITs, addressing the long-standing puzzles of Mooij correlations and the related resistivity saturation.This project will also involve training of graduate students in theoretical and computational condensed matter physics. The PI will continue to promote and enhance broad scientific and technological understanding and the importance of fundamental research to the general public through various outreach activities. These will include: 1) Presenting lectures at elementary schools in order to popularize science and technology and to bring recent scientific discoveries within reach of young students; 2) Serving as a judge at annual regional Science Fairs that involve K-12 students from public and private schools within the region; 3) Working with high-school summer interns as a part of the "Florida Young Scholar" program, enabling them to bring cutting-edge science to the public at large through the development of JAVA animations and other web-based materials.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.