Artificial Atoms

人造原子

• 批准号: 0353209
• 负责人: Marc Kastner
• 金额: $ 34.79万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0353209&HistoricalAwards=false
• 关键词: Artificial; Atoms

When the tunnel barriers confining electrons in an artificial atom are transmitting enough, the motion of electrons in the leads becomes correlated with the motion of electrons in the isolated region. The most dramatic manifestation of these correlations is the Kondo effect. Recent experiments have shown that the physics of the Kondo effect is fundamentally different when there are two unpaired electrons in the isolated region rather than one. The way the correlations develop with decreasing temperature or decreasing magnetic field is expected to be sensitive to the geometry of the leads. Specific theoretical predictions have been made for this situation, and a major part of the work proposed for this project is designed to test these predictions. More generally, the single-electron transistors used for these studies are an outstanding laboratory for studying the physics of nanostructures, some of which may eventually have important technological applications. Research on semiconductor nanostructures has also proven to be an outstanding training ground for young physicists. Former students and postdoctoral associates educated in this group have positions in small companies, large companies and universities. A significant number of these have been women and minorities. Continued recruitment of undergraduates, graduate students and postdocs, especially women and minorities is planned.Advances in nano-science and engineering let one make transistors so small that the electrons in them behave quantum mechanically. Understanding this quantum behavior is intrinsically interesting, but it is also important for understanding how to make useful electronic devices at the nanometer length scale. When electrons are confined to nanometer length scales they can be thought of as artificial atoms. Bringing an artificial atom into close contact with a metal creates a chemical bond between the atom and the metal. This project studies how that chemical bond depends on the number of electrons in the artificial atom. Because transistors made with artificial atoms turn on and off again for every electron added to them they are called single-electron transistors. In addition to its interest for technology, research on single electron transistors has proven to be an outstanding training ground for young physicists. Former students and postdoctoral associates educated in this group have positions in small companies, large companies and universities. A significant fraction of these have been women and minorities. Continued recruitment of undergraduates, graduate students and postdocs, especially women and minorities is planned.

当人工原子中限制电子的隧道势垒足够透射时，引线中电子的运动与隔离区中电子的运动相关。 这些相关性最引人注目的表现是近藤效应。 最近的实验表明，当孤立区域中有两个未成对电子而不是一个时，近藤效应的物理性质是根本不同的。 随着温度降低或磁场降低，相关性的发展方式预计对电极导线的几何形状敏感。 针对这种情况已经做出了具体的理论预测，本项目提出的工作的主要部分旨在验证这些预测。 更一般地说，用于这些研究的单电子晶体管是研究纳米结构物理学的杰出实验室，其中一些最终可能具有重要的技术应用。 对半导体纳米结构的研究也被证明是年轻物理学家的一个出色的训练基地。 在这个群体中接受教育的前学生和博士后同事在小公司，大公司和大学中任职。 其中相当多的人是妇女和少数民族。 计划继续招收本科生、研究生和博士后，特别是女性和少数民族。纳米科学和工程的进步使人们能够制造出如此之小的晶体管，以至于其中的电子表现出量子力学行为。 理解这种量子行为本质上是有趣的，但它对于理解如何在纳米尺度上制造有用的电子器件也很重要。 当电子被限制在纳米长度尺度时，它们可以被认为是人造原子。将人造原子与金属紧密接触，在原子和金属之间产生化学键。 该项目研究化学键如何取决于人造原子中的电子数量。 因为用人造原子制造的晶体管每增加一个电子就会开关一次，所以它们被称为单电子晶体管。 除了对技术的兴趣，单电子晶体管的研究已被证明是年轻物理学家的一个出色的训练基地。 在这个群体中接受教育的前学生和博士后同事在小公司，大公司和大学中任职。 其中很大一部分是妇女和少数民族。 计划继续招收本科生、研究生和博士后，特别是妇女和少数民族。