Study of Quantum Hall Liquids Using Single Electron Transistors and Emerging Two-Dimensional Electron Systems

使用单电子晶体管和新兴二维电子系统研究量子霍尔液体

• 批准号: 1006500
• 负责人: Cagliyan Kurdak
• 金额: $ 36万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-15 至 2015-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1006500&HistoricalAwards=false
• 关键词: Study; Quantum; Hall; Liquids; Using

Non-technical Abstract:At high magnetic fields, electrons that are confined to move in two directions form new states of matter known as fractional quantum Hall liquids. In such matter, new particles emerge with very unusual properties. For example, in most conductors electrical current is normally carried by electrons with a well-known charge of e. By contrast, in fractional quantum Hall liquids, current is carried by unusual particles with fractional charge of e/3, e/5, and so on. Since electrons are known to be indivisible, the emergence of such fractionally charged particles has been one most fascinating manifestations of many electron quantum phenomena. This project will study these fascinating new particles using devices called single electron transistors. The single electron transistor can be turned on and off by a single electron, and is the most sensitive charge sensor in existence. This powerful transistor will also be used to study magnetic properties of stacked layers of these unusual liquids. In addition to conventional semiconductor structures, the work will expanded to emerging two-dimensional electron systems based on higher bandgap semiconductors. On the educational side, the project will provide excellent training for graduate and undergraduate students. The outreach activities, such as physics demonstrations and public lectures, which typically focus on semiconductors, will benefit participating local high school students. Technical Abstract:This project will address some of the long-standing fundamental problems in two-dimensional electron systems. Excitations of fractional quantum Hall liquids are predicted to carry fractional charge and obey unusual fractional statistics different from those of fermions or bosons. Fractionalization and statistics of quasiparticles will be studied using single electron transistors (SETs) in an Aharonov-Bohm type interference structure. SETs will also be used to study bulk transport properties in quantum Hall liquids. In particular longitudinal conductivity measurements will be performed in the deep insulating regime where conventional transport measurements are not doable. Persistent eddy currents will be investigated in stacked layers of quantum Hall liquids to test an interesting prediction that such stacked layers can be perfectly diamagnetic at zero temperature. In addition to GaAs/AlGaAs heterostructures, quantum transport properties of emerging two-dimensional electron systems based on higher bandgap semiconductors will be investigated in both gated Hall bar and quantum point contact structures. On the educational side, the project will provide excellent training for graduate and undergraduate students. The outreach activities, such as physics demonstrations and public lectures, which typically focus on semiconductors, will benefit participating local high school students.

非技术摘要：在强磁场下，被限制在两个方向上运动的电子形成新的物质状态，称为分数量子霍尔液体。在这种物质中，出现了具有非常不寻常性质的新粒子。例如，在大多数导体中，电流通常由电荷为e的电子携带。相比之下，在分数量子霍尔液体中，电流由分数电荷为e/3、e/5的不寻常粒子携带，依此类推。由于人们知道电子是不可分割的，这种分数电荷粒子的出现是许多电子量子现象中最引人入胜的表现之一。这个项目将使用称为单电子晶体管的设备来研究这些令人着迷的新粒子。单电子晶体管可以由单电子开启和关闭，是现有的最灵敏的电荷传感器。这种强大的晶体管也将被用来研究这些不寻常的液体堆积层的磁性。除了传统的半导体结构外，这项工作还将扩展到基于更高带隙半导体的新兴二维电子系统。在教育方面，该项目将为研究生和本科生提供出色的培训。推广活动，如物理演示和公开讲座，通常侧重于半导体，将使参与其中的当地高中生受益。技术摘要：这个项目将解决二维电子系统中一些长期存在的基本问题。分数量子霍尔液体的激发被预言带有分数电荷，并服从不同于费米子或玻色子的不寻常的分数统计。在Aharonov-Bohm类型的干涉结构中，将使用单电子晶体管(SETS)来研究准粒子的细分和统计。SET还将用于研究量子霍尔液体的整体输运性质。特别是，纵向电导率测量将在深层绝缘区域进行，在那里常规的传输测量是不可行的。将研究量子霍尔液体堆积层中的持续涡流，以验证一个有趣的预测，即这种堆积层在零温度下可以完全抗磁。除了GaAs/AlGaAs异质结外，还将研究基于高禁带半导体的新兴二维电子系统在门控霍尔棒和量子点接触结构中的量子输运特性。在教育方面，该项目将为研究生和本科生提供出色的培训。推广活动，如物理演示和公开讲座，通常侧重于半导体，将使参与其中的当地高中生受益。