Optically Pumped Nuclear Magnetic Resonance in the Quantum Hall Regimes

Barrett 9807184这是一个二维电子系统（2DES）领域的凝聚态物理项目，采用delta掺杂砷化镓/砷化铝镓多量子威尔斯阱制造。当暴露于垂直于2D平面的磁场时，这样的2DES表现出复杂的电输运行为，例如分数量子霍尔效应（Fractional Quantum Hall Effect，FQHE）。2DES将使用一种称为光泵核磁共振（OPNMR）的新技术进行研究。目的是了解电子-电子相互作用的性质，负责的电子-电子相互作用。OPNMR方法在提供关于电子自旋在多粒子基态中的作用的具体信息方面是独一无二的，并且基本激发引起了ECOHE。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。该项目代表了凝聚态物理学的前沿。通过与朗讯实验室的合作，提供了ECOHE研究所需的复杂材料。这项研究为研究生提供了一个学习基础物理和学习尖端实验技术的绝佳机会，这些技术在半导体物理和微电子行业的广泛领域中有应用。这是一个凝聚态物理项目，主要研究电子的电学性质，这些电子在很大程度上被限制在二维平面内移动。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，发现主要变化是磁场的函数。这种行为被称为分数量子霍尔效应（Fractional Quantum Hall Effect，缩写为FQHE）。目前还不能完全了解这个区域，它代表了凝聚态物理学的前沿。该项目采用了一种独特的核磁共振（NMR）方法，该方法可以检测到电子的磁性，这些电子是磁共振的基础。这些结果具有根本的意义，并为与磁共振相关的磁性竞争理论提供了重要的测试。通过与朗讯实验室的合作，提供了ECOHE研究所需的复杂材料。该研究为研究生提供了一个学习基础物理和学习尖端实验技术的绝佳机会，这些技术在半导体物理和微电子行业的广泛领域中具有应用。

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.