Electron Transport in Quantum Dots

将在UCSB的砷化镓/砷化铝镓异质结构上制备双量子点和三量子点耦合人工分子，包括点链和点环。半导体上的这种结构将使PI能够补偿杂质和缺陷对电子能量和点对点耦合的影响。超低温下的库仑封锁和点电容将作为单量子点和双量子点电子态的光谱工具。其他探针，如通过微型化带状线的局部微波激发，以及目前正在开发的空间分辨扫描探针测量，将用于表征单个和耦合点中的电子状态和输运。目的是阐明耦合点中电子态的性质，并寻找可能的集体量子现象。电子在这些结构中的行为，无论是出于实际原因还是出于基本原因，都引起了人们极大的兴趣。通过耦合量子点控制单电子的运动是电子和计算新方法的基础。这个项目研究半导体“量子点”，这种结构非常小，也被称为人造原子和分子。它们的制作过程很复杂，需要哈佛大学和加州大学圣巴巴拉分校的工作人员合作。电子在这些结构中的行为，无论是出于实际原因还是出于基本原因，都引起了人们极大的兴趣。通过耦合量子点控制单电子的运动是电子和计算新方法的基础。例如，目标是开发单电子器件，其中每个位由单个电子表示，其状态可以进行光学切换。与“真正的”分子不同，量子点的大小和耦合可以通过制造方法来改变，从而产生通常在分子中找不到的新现象。超低温下的库仑阻塞和点电容的测量将作为单量子点和耦合量子点中电子态的光谱工具。* * *

9501438 Westervelt Coupled two and three quantum dots, artificial molecules, including chains and rings of dots will be fabricated on gallium- arsenide/aluminum-gallium-arsenide heterostructures from UCSB. Such structures on semiconductors will enable the PI to compensate for the effect of impurities and defects on the energy of the electrons and the dot to dot coupling. Coulomb blockade and dot capacitance at ultra-low temperatures will be used as spectroscopic tools for electron states in single and couple quantum dots. Additional probes such as localized microwave excitation via miniaturized striplines, and spatially resolved scanning probe measurements currently under development will be used to characterize electron states and transport in single and coupled dots. The objective is to elucidate the nature of electron states in coupled dots and to search for possible collective quantum phenomena. The behavior of electrons inside these structures is of great current interest, both for practical and for fundamental reasons. The controlled motion of single electrons through coupled quantum dots is the basis for new approaches to electronics and computation. %%% This project investigates semiconductor "quantum dot", structures which are so small that they are also referred to as artificial atoms and molecules. Their fabrication is complex and involves collaboration between workers at Harvard and UC Santa Barbara. The behavior of electrons inside these structures is of great current interest, both for practical and for fundamental reasons. The controlled motion of single electrons through coupled quantum dots is the basis for new approaches to electronics and computation. For example, a goal is to develop single electron devices in which each bit is represented by a single electron, whose state may be optically switched. Unlike "real" molecules, the size and cou pling between the quantum dots can be varied by fabrication methods to produce new phenomena not normally found in molecules. Measurements of the Coulomb blockade and dot capacitance at ultra-low temperatures will be used as spectroscopic tools for electron states in single and coupled quantum dots. ***