Electron Transport in Nanostructures and Single Molecules

这个研究项目集中于两类纳米结构的电子特性，金属纳米粒子和单分子，它们是相关的，因为它们足够小，可以操纵电子在单个量子力学状态中流动，而不是像在大型设备中那样通过连续的能级。这项工作的目标是开发新的制造技术，将纳米颗粒和单分子结合到电子器件中，并利用这些技术来获得对这些系统中控制电子传输的物理学的新见解。最终目标是在单量子态和单个化学键的水平上理解电传导。这项工作将解决一些基本问题：在纳米结构中作用于电子的不同力如何影响量子能级的光谱？什么物理过程会影响纳米结构和分子的自旋依赖输运？单分子中的电子传递在哪些方面与纳米粒子相似？由于振动、电荷重构、溶剂效应和筛选的差异，它们又在哪些方面有所不同？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，以及口头和书面表达工作成果的技能。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生涯做好准备。通过将电子设备缩小到纳米尺度，探索一种新的机制成为可能，在这种机制中，电子被操纵在单个能级上流动，而不是通过有效的连续状态谱。这个研究项目将开发新的制造纳米级器件的方法，它将研究通过单个能级控制电子流动的技术，并将确定这种能力是否可以导致在更大的器件中不可能实现的器件功能。这项工作将包括两种类型的纳米级构建模块，直径小于10纳米的金属颗粒和设计和合成的用作晶体管的单个分子。最终的目标将是在单个化学键的水平上理解电传导。这项工作将集中在基本的物理问题上，这些问题与电子在能级之间移动的速率有关，作用于电子的不同力的影响，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，分子装置如何与固态结构不同。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，以及口头和书面表达工作成果的技能。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生涯做好准备。

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.