Electronic Transport in Thin Film Nanostructures

本研究的主要目的是研究硅衬底上纳米薄膜结构中的量子电输运。该项目侧重于原子线阵列和原子光滑金属薄膜。在一定的生长条件下，单个金属原子“自组装”成平行“原子线”的宏观域，线之间的间距相等但可调。这些阵列非常适合研究量子电输运的基本原理、系统维数的函数和费米表面拓扑结构，使用纳米探针，如四尖扫描隧道显微镜，以及宏观测量探针，如电子束或激光束。原子光滑的金属薄膜将通过一种由量子尺寸效应驱动的新型自组装机制合成，该机制允许系统地研究与量子干涉、量子限制和经典尺寸效应相关的电导率。这些研究将使研究人员能够提取出与未来纳米级设备操作相关的关键特征。田纳西大学和附近的纳米材料科学中心拟议的科学和支持基础设施为具有国际竞争力的学生和博士后的教育和培训提供了良好的环境。这些年轻人将在高技能劳动力中占据一席之地，在当今高科技社会中继续推动创新和繁荣。量子电输运是纳米科学的核心。将单个原子或分子和小的化学基团组装成更快、更强大的电子设备的想法不再属于科幻小说的领域。最近，研究人员将他们的首个分子级电子电路连接起来，这一成就被《科学》杂志选为“2001年的重大突破”。研究人员现在面临着一项艰巨的任务，即将这种新技术从基本的电子元件应用到复杂的集成电路中，从而可以与硅的低成本性能和可靠性相媲美。要达到这种复杂程度，除了芯片制造和设计方面明显需要的革命之外，还需要几项科学突破。在这个项目中，研究人员将单个金属原子排列成“原子线”，或者将原子排列成只有几个原子层厚的完美光滑的薄膜。这些纳米结构材料是理想的模型系统，将允许研究人员探索纳米材料中电流的基本原理和关键特性。量子输运将最基本的自然定律，即量子力学，与应用电气工程和新兴材料技术结合在一起。田纳西大学和附近能源部纳米材料科学中心的拟议科学和支持基础设施为使用专门的国家研究设施的具有国际竞争力的学生和博士后的教育和培训提供了良好的环境。这些年轻人将在高技能劳动力中占据一席之地，在当今高科技社会中继续推动创新和繁荣。

The primary objective of the proposed research is the investigation of quantum electrical transport in thin film nanostructures on silicon substrates. The project focuses on atomic-wire arrays and on atomically smooth metal films. Under certain growth conditions, individual metal atoms "self-assemble" into macroscopic domains of parallel "atom wires" with equal but tunable spacing between the wires. These arrays are ideal for studying the fundamentals of quantum electrical transport a function of system dimensionality and Fermi surface topology using nanoscopic probes such as a four-tip Scanning Tunneling Microscope, as well as macroscopic measurement probes such as electron- or laser beams. Atomically smooth metal films will be synthesized via a novel self-assembly mechanism that is driven by the quantum-size effect, which allows for a systematic investigation of the conductivity in relation to quantum interference, quantum confinement, and classical size effects. These studies will allow researchers to extract the key characteristics that are relevant for the operation of future nanoscale devices. The proposed science and supporting infrastructure at The University of Tennessee and nearby Center for Nanophase Materials Sciences provide an excellent setting for the education and training of internationally competitive students and postdocs. These young people will take their place in the highly skilled workforce that will continue to drive innovation and prosperity in today's high-tech society.Quantum electrical transport is at the heart of nanoscience. The idea of assembling single atoms or molecules and small chemical groups into much faster and powerful electronic devices no longer belongs to the realm of science fiction. Recently, researchers wired up their first molecular-scale electronic circuits, an achievement Science Magazine selected as the "Breakthrough of 2001". Researchers now face the daunting task of taking this new technology from basic electronic components to complex integrated circuits that can rival silicon's low cost performance and reliability. Reaching that level of complexity requires several scientific breakthroughs besides the obviously needed revolution in chip fabrication and design. In this project, researchers will align individual metal atoms into "atomic wires" or arrange the atoms into a perfectly smooth film that is only a few atom layers thick. These nanostructured materials are ideal model systems that will allow researchers to explore the fundamentals and key characteristics of electrical currents in nanophase materials. Quantum transport marries the most fundamental laws of nature, namely quantum mechanics, with applied electrical engineering and emerging materials technologies. The proposed science and supporting infrastructure at The University of Tennessee and the nearby Center for Nanophase Materials Sciences of the Department of Energy provide an excellent setting for the education and training of internationally competitive students and postdocs using specialized national research facilities. These young people will take their place in the highly skilled workforce that will continue to drive innovation and prosperity in today's high-tech society.