Electron Transport in Nanostructures and Single Molecules

这项研究项目主要关注两类纳米结构的电子性质，金属纳米粒子和单分子，这两类结构之间的联系在于，它们足够小，以至于电子可以被操纵通过单独的量子力学状态，而不是像在较大的设备中那样，通过能级的连续体。这项拟议的工作既旨在开发将纳米粒子和单分子纳入电子设备的新制造技术，也旨在利用这些技术来获得对这些系统中电子传输的物理管理的新见解。最终目标是在单个量子态和单个化学键的水平上理解电导。这项工作将解决一些基本问题：作用于纳米结构中电子的不同力如何影响量子能级的光谱？哪些物理过程会影响通过纳米结构和分子的自旋相关输运？由于振动、电荷重新配置、溶剂效应和筛选上的差异，单分子中的电子传输在哪些方面与纳米颗粒相似，又在哪些方面不同？参与该项目的研究生和本科生将获得纳米技术方面的广泛专业知识，以及口头和书面介绍他们的工作的技能。这种培训将为他们在教育、研究和/或商业领域的各种可能的职业做好准备。通过将电子设备缩小到纳米级，已经有可能探索一种新的制度，在这种制度下，电子被操纵以通过单个能级流动，而不是通过有效连续的状态光谱。这个研究项目将开发新的制造方法来制造纳米器件，它将研究控制电子通过单一能级流动的技术，并将确定这种能力是否会导致设备功能在更大的设备中无法实现。这项工作将包括两种类型的纳米级构建块，直径小于10纳米的金属颗粒，以及设计和合成的充当电晶体管的单个分子。最终目标将是在单个化学键的水平上了解导电。这项工作将集中在基本的物理问题上，这些问题涉及电子在能级之间移动的速度，不同作用力对电子的影响，电子自旋在影响其运动中的作用，以及由于分子可能扭曲和振动的事实，分子装置可能与固态结构有何不同。参与该项目的研究生和本科生将获得纳米技术方面的广泛专业知识，以及口头和书面介绍他们的工作的技能。这项培训将为他们在教育、研究和/或商业领域的各种可能职业做好准备。

This research project focuses on the electronic properties of two classes of nanostructures, metal nanoparticles and single molecules, which are related in that they are small enough that electrons can be manipulated to flow via individual quantum-mechanical states, rather than through a continuum of energy levels as is the case in larger devices. The proposed work is aimed both at developing new fabrication techniques for incorporating nanoparticles and single molecules into electrical devices, and also at exploiting these techniques to gain new insights into the physics governing electron transport in these systems. The ultimate goal is to understand electrical conduction at the level of single quantum states and individual chemical bonds. The work will address a number of fundamental questions: How do the different forces, which act on electrons in nanostructures, affect the spectrum of quantum levels? What physical processes affect spin-dependent transport through nanostructures and molecules? In what ways is electron transport in single molecules similar to nanoparticles, and in what way is it different, due to vibrations, charge reconfiguration, solvent effects, and differences in screening? The graduate and undergraduate students working on the project will gain broad expertise in nanotechnology, as well as skills in presenting their work verbally and in writing. This training will prepare them for a variety of possible careers in education, research, and/or business.By shrinking electronic devices to the nanometer scale, it has become possible to explore a new regime, where electrons are manipulated to flow through individual energy levels rather than through an effectively continuous spectrum of states. This research project will develop new fabrication methods to make nanoscale devices, it will investigate techniques for controlling the flow of electrons through single energy levels, and it will determine whether this capability can lead to device functions not possible in larger devices. The work will incorporate two types of nanoscale building blocks, metal particles less than 10 nm in diameter and individual molecules designed and synthesized to act as electrical transistors. The ultimate goal will be to understand electrical conduction at the level of individual chemical bonds. The work will focus on fundamental physical questions having to do with the rates at which electrons move between energy levels, the effects of different of forces acting on the electrons, the role of the electron's spin in affecting its motion, and how molecular devices may differ from solid-state structures due to the fact that molecules may twist and vibrate. The graduate and undergraduate students working on the project will gain broad expertise in nanotechnology, as well as skills in presenting their work verbally and in writing. This training will prepare them for a variety of possible careers in education, research, and/or business.