Cooperative Effects Of Impurities On Electron Transport In Low-Dimensional Nanostructures

技术概述：该奖项支持凝聚态物理在准一维系统中输运的理论研究和教育。研究超薄导线的输运特性，如碳纳米管、半导体纳米线、聚合物纳米纤维、石墨烯带等。研究的动机是这样一个事实，即这种系统通常对温度、外部场和其他实验可调参数以及大样本间的可变性表现出明显的非常规依赖。一项理论研究计划正在进行，旨在提供理论描述和计算机模拟，以了解这些异常背后的物理。最重要的输运特性是总体平均电导率，它对内部和外部参数的依赖，它的统计分布，以及它的时空波动（噪声）。提出的研究的特别重点是阐明合作杂质效应和库仑相互作用在观察到的输运定律的根本作用。此外，在有限浓度的掺杂剂和缺陷的系统中，由于多种杂质的联合作用而产生的一些相对较新的现象也得到了解决。PI将调查这些现象在这种一维和准一维导体中普遍存在的程度。预计这种现象源于降维对电流路径施加的严格几何约束和这些系统典型的强电子-电子相互作用。这项研究是在一个拥有不同种族学生的机构进行的，允许PI开发研究项目的组成部分，可以与一个有才华和不同种族的研究生和本科生团队密切合作。研究参与让学生获得技术知识和解决问题的能力。本科生尤其有机会在一个没有的环境中参与尖端研究。除此之外，PI还扩大了该项目的影响，为地区高中生举办了暑期科学营活动。非技术总结：该奖项支持凝聚态物理学的理论研究和教育，研究电荷如何通过超薄线状材料系统，这是纳米技术发展的一部分。本提案所解决的科学问题涉及到纳米技术核心要素——电子元件的极端小型化所带来的特殊和不寻常的特性。极端小型化的具体例子包括一些长而窄的结构，它们被称为纳米线。纳米线可以由多种材料制成，如金属、聚合物或半导体。在分子和原子水平上，具有非晶结构（即非晶结构）的纳米线的输运具有许多独立的特性。当材料的性质非常不同时，了解相似的性质的起源是纯科学和应用科学研究人员广泛考虑的未来技术应用的浓厚兴趣。对这些由纳米结构中非常规的电流和热流特性引起的问题给出可靠的答案，是纳米技术未来应用的基础。这项研究是在一个拥有不同种族学生的机构进行的，允许PI开发研究项目的组成部分，可以与一个有才华和不同种族的研究生和本科生团队密切合作。研究参与让学生获得技术知识和解决问题的能力。本科生尤其有机会在一个没有的环境中参与尖端研究。除此之外，PI还扩大了该项目的影响，为地区高中生举办了暑期科学营活动。

TECHNICAL SUMMARY:This award supports theoretical research and education in condensed matter physics on the subject of transport in quasi-one-dimensional systems. Investigations will be undertaken into transport properties of ultra-thin wires, e.g. carbon nanotubes, semiconductor nanowires, polymer nanofibers, graphene ribbons. Research is motivated by the fact that such systems often show distinctly unconventional dependences on temperature, external fields, and other experimentally tunable parameters, as well as large sample-to-sample variability. A program of theoretical investigations is undertaken towards providing theoretical descriptions and computer simulations to provide understanding the physics behind such anomalies. The transport characteristics of primary importance are ensemble-averaged conductivity, its dependence on intrinsic and external parameters, its statistical distribution, and its temporal and spatial fluctuations (noise). The special focus of the proposed research is to elucidate the role of cooperative impurity effects and Coulomb interactions at the root of the observed transport laws. Additionally, some relatively new phenomena that arise from a combined action of multiple impurities in systems with a finite concentration of dopants and defects are addressed. The PI will investigate the degree to which these phenomena are pervasive in such one-dimensional and quasi-one-dimensional conductors. It is expected that the phenomena originate from the tight geometric constraints imposed on the current pathways by the reduced dimensionality and from strong electron-electron interactions typical of these systems.This research is undertaken at an institution with an ethnically diverse student body, allowing the PI to develop components of the research program that can be conducted in a close collaboration with a team of talented and ethnically diverse graduate and undergraduate students. The research engagement allows students to gain technical knowledge and problem-solving skills. The undergraduate students particularly have opportunities to participate in cutting-edge research in an environment not otherwise available. Beyond this, the PI extends the impact of the program with outreach activities at summer science camps for area high school students.NON-TECHNICAL SUMMARY:This award supports theoretical research and education in condensed matter physics on how electric charge moves through systems of ultra-thin wire-like materials that are part of the developments in nanotechnology. The scientific questions addressed in this proposal involve the peculiar and unusual properties that develop with extreme miniaturization of electronic components that are the core elements of nanotechnology. Particular examples of the extreme miniaturization include a number of structures that are long but very narrow and are termed nanowires. Nanowires may be constructed from a variety of materials such as metals, polymers or semiconductors. Independent of many specifics, there are universal characteristics of transport in nanowires that have amorphous structure, i.e. noncrystalline, at the molecular and atomic level. Understanding the origins of properties that are similar when the materials are extremely different is of keen interest for future technological applications being considered by a broad community of researcher in pure and applied sciences. Reliable answers to such questions that arise from unconventional properties of electrical and heat flow in nanostructures is fundamental to most future applications on nanotechnology. This research is undertaken at an institution with an ethnically diverse student body, allowing the PI to develop components of the research program that can be conducted in a close collaboration with a team of talented and ethnically diverse graduate and undergraduate students. The research engagement allows students to gain technical knowledge and problem-solving skills. The undergraduate students particularly have opportunities to participate in cutting-edge research in an environment not otherwise available. Beyond this, the PI extends the impact of the program with outreach activities at summer science camps for area high school students.