Electron Transport in Semiconductor Nanostructures

半导体纳米结构中的电子传输

• 批准号: 9802242
• 负责人: Robert Westervelt
• 金额: $ 27万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-08-15 至 2001-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9802242&HistoricalAwards=false
• 关键词: Electron; Transport; Semiconductor; Nanostructures

w:\awards\awards96\*.doc 9802242 Westervelt This experimental research project investigates the behavior of electrons in tunnel-coupled quantum dots. In an apt analogy, such systems can be regarded as artificial molecules, the individual dots being considered as atoms. The fundamental characteristics of electrons in these systems; how electrons are shared between dots, the energy of shared electron states, and how electrons move through coupled dot circuits; are of interest. Specific measurements include Coulomb blockade spectroscopy of small tunnel-coupled dots (less than 100 electrons per dot); Coulomb blockade spectroscopy of tunnel-coupled dots in the quantum Hall regime; transport through single quantum dots with partially open leads, predicted to show interesting many body effects; and transport through open electron wave resonators. Dot samples are made at Harvard using electron beam lithography on GaAs/AlGaAs wafers grown via molecular beam epitaxy at Univ. California Santa Barbara. This research program is interdisciplinary in nature and involves one or more graduate students, who receive excellent training in preparation for careers in industry, government laboratories or academia. %%% This experimental research project investigates the behavior of electrons in semiconductor quantum dots coupled by quantum- mechanical electron tunneling. In an apt analogy, such systems can be regarded as artificial molecules, the individual dots being considered as atoms. The "quantum dot" is a small region in the surface of a GaAs/AlGaAs wafer, similar to those used in advanced microelectronic devices. A two-dimensional electron gas is produced just below the surface of the entire wafer, and then miniature electrodes are deposited using electron beam lithography which can isolate a tiny region containing as few as 100 electrons, called a qu antum dot. The fundamental characteristics of electrons in these systems; how electrons are shared between dots, the energy of shared electron states, and how electrons move through coupled dot circuits, are of interest. Specific measurements include Coulomb blockade spectroscopy of small tunnel-coupled dots (less than 100 electrons per dot); Coulomb blockade spectroscopy of tunnel-coupled dots in the quantum Hall regime; transport through single quantum dots with partially open leads, predicted to show interesting many body effects; and transport through open electron wave resonators. Dot samples are made at Harvard using electron beam lithography on GaAs/AlGaAs wafers grown via molecular beam epitaxy at Univ. California Santa Barbara. The research is relevant to future electronics in which devices will approach the size of large molecules. At this size scale quantum mechanics is important even at room temperature. Quantum phenomena offer new approaches to computation ranging from ultra dense single-electron memories to quantum computers projected to give an exponential increase in speed. The research here addresses the fundamental characteristics of quantum mechanical electron states and electron transport in tunnel-coupled semiconductor nanostructures as a first step toward these possible applications. This research program is interdisciplinary in nature and involves one or more graduate students, who receive excellent training in preparation for careers in industry, government laboratories or academia. ***

W：\奖项\ Awards96 \*。doc 9802242 Westervelt这个实验研究项目研究了电子在隧道耦合量子点中的行为。在恰当的类比中，这样的系统可以被视为人造分子，单个点被视为原子。这些系统中电子的基本特征；点之间的电子如何共享，共享电子状态的能量以及电子如何通过耦合点电路移动；很感兴趣。 特定的测量包括小隧道耦合点的库仑阻滞光谱（每个点少于100个电子）； 量子厅制度中隧道耦合点的库仑封锁光谱；通过具有部分开放铅的单个量子点进行运输，预计会显示出有趣的许多身体效应。 并通过开放的电子波谐振器传输。 DOT样品是在Harvard使用电子束光刻在Univ上通过分子束外延生长的GAAS/藻类晶片上的电子束光刻制成的。加利福尼亚州圣塔芭芭拉。该研究计划本质上是跨学科的，涉及一名或多个研究生，他们接受了为工业，政府实验室或学术界的职业做准备的出色培训。 %% %%这个实验研究项目研究了通过量子机械电子隧道耦合的半导体量子点中电子的行为。在恰当的类比中，这样的系统可以被视为人造分子，单个点被视为原子。 “量子点”是GAAS/藻类晶片表面中的一个小区域，类似于高级微电器设备中使用的小区域。在整个晶圆的表面下方产生二维电子气体，然后使用电子光束光刻沉积微型电极，该电子光线光刻可以分离一个小区域，其中包含少于100个电子的微小区域，称为Quant dot。 这些系统中电子的基本特征；如何在点之间共享电子，共享电子状态的能量以及电子如何通过耦合点电路移动。 特定的测量包括小隧道耦合点的库仑阻滞光谱（每个点少于100个电子）； 量子厅制度中隧道耦合点的库仑封锁光谱；通过具有部分开放铅的单个量子点进行运输，预计会显示出有趣的许多身体效应。并通过开放的电子波谐振器传输。 DOT样品是在Harvard使用电子束光刻在Univ上通过分子束外延生长的GAAS/藻类晶片上的电子束光刻制成的。 加利福尼亚州圣塔芭芭拉。该研究与未来的电子产品有关，其中设备将接近大分子的大小。在这种尺寸上，即使在室温下，量子力学也很重要。量子现象为计算提供了新的方法，从超密集的单电子记忆到预计速度提高的量子计算机。 这里的研究介绍了隧道耦合半导体纳米结构中量子机械电子状态和电子传输的基本特征，这是朝着这些可能应用的第一步。该研究计划本质上是跨学科的，涉及一名或多个研究生，他们接受了为工业，政府实验室或学术界的职业做准备的出色培训。 ***