Optically Pumped Nuclear Magnetic Resonance in the Quantum Hall Regimes

量子霍尔体系中的光泵浦核磁共振

• 批准号: 9807184
• 负责人: Sean Barrett
• 金额: $ 28.5万
• 依托单位: Yale 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 2002-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9807184&HistoricalAwards=false
• 关键词: Optically; Pumped; Nuclear; Magnetic; Resonance

Barrett9807184This is a condensed matter physics project in the area of two-dimensional electron systems (2DES), fabricated with delta-doped gallium arsenide/aluminum gallium arsenide multiple quantum wells. Such 2DES exhibit complex electrical transport behavior, such as the fractional quantum Hall effect (FQHE), when exposed to a magnetic field normal to the 2D planes. The 2DES will be investigated using a new technique called optically pumped nuclear magnetic resonance (OPNMR). The objective is to understand the nature of electron-electron interactions that are responsible for the FQHE. The OPNMR method is unique in providing specific information about the role of electron spin in the many-particle ground states, and elementary excitations, that give rise to the FQHE. This information can be related to novel geometrical magnetization distributions, called "skyrmions" that have been predicted in the 2DES and discovered via the OPNMR method. The project represents a frontier of condensed matter physics. The sophisticated materials required for the FQHE research are provided via a collaboration with Lucent Laboratories. The research provides an outstanding opportunity for graduate students to study fundamental physics and to learn cutting-edge experimental techniques that have applications in a wide area of semiconductor physics and the microelectronics industry.%%%This is a condensed matter physics project that deals with the electrical properties of electrons that are largely confined to move in a two-dimensional plane. These are two-dimensional electron systems (2DES). When a magnetic field is applied perpendicular to the plane of the electrons, and the electrical transport is measured, it is found that major changes occurs as a function of magnetic field. Some of this behavior is known as the fractional quantum Hall effect (FQHE). A full understanding of the FQHE is not available and the area represents a frontier of condensed matter physics. This project employs a unique nuclear magnetic resonance (NMR) method that senses the magnetic properties of the electrons that underlie the FQHE. The results are of fundamental interest and provide important tests of competing theories of the magnetism associated with the FQHE. The sophisticated materials required for the FQHE research are provided via a collaboration with Lucent Laboratories. The research provides an outstanding opportunity for graduate students to study fundamental physics and to learn cutting-edge experimental techniques that have applications in a wide area of semiconductor physics and the microelectronics industry.

这是一个二维电子系统（2DES）领域的凝聚态物理项目，由掺杂的砷化镓/砷化镓铝多量子阱制成。当暴露在与二维平面垂直的磁场中时，这种2DES表现出复杂的电传输行为，例如分数量子霍尔效应（FQHE）。2DES将使用一种称为光泵核磁共振（OPNMR）的新技术进行研究。目的是了解产生FQHE的电子-电子相互作用的本质。OPNMR方法在提供电子自旋在多粒子基态和产生FQHE的基本激发中所起作用的特定信息方面是独一无二的。这些信息可能与新的几何磁化分布有关，称为“skyrmions”，已在2DES中预测并通过OPNMR方法发现。这个项目代表了凝聚态物理的前沿。FQHE研究所需的复杂材料是通过与朗讯实验室合作提供的。该研究为研究生提供了一个学习基础物理学和学习在半导体物理和微电子工业广泛应用的尖端实验技术的绝佳机会。这是一个凝聚态物理项目，主要研究在二维平面上运动的电子的电学性质。这些是二维电子系统（2DES）。当垂直于电子平面施加磁场并测量电输运时，发现主要的变化是作为磁场的函数发生的。其中一些行为被称为分数量子霍尔效应（FQHE）。对FQHE的全面了解是不可用的，该地区代表了凝聚态物理的前沿。该项目采用了一种独特的核磁共振（NMR）方法来感知构成FQHE的电子的磁性。这些结果具有根本性的意义，并为与FQHE相关的磁性竞争理论提供了重要的测试。FQHE研究所需的复杂材料是通过与朗讯实验室合作提供的。该研究为研究生提供了一个学习基础物理学和学习在半导体物理和微电子工业广泛应用的尖端实验技术的绝佳机会。