Experimental Investigation of Delocalization and Phase Diagram in Quantum Hall Systems

量子霍尔系统离域和相图的实验研究

• 批准号: 9705439
• 负责人: Hong-Wen Jiang
• 金额: $ 24.6万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-08-15 至 2000-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9705439&HistoricalAwards=false
• 关键词: Experimental; Investigation; Delocalization; Phase; Diagram

9705439 Jiang This experimental research project focuses on the 2-D electron gas in the quantum Hall effect regime, specifically on the phase diagram and a localization-delocalization transition as afffected by disorder . Gated GaAs/AlGaAs devices will be used to gain control of the effective disorder of the experimental system. High magnetic field transport experiments will be carried out to study the magnetic-field-induced delocalization transition and to determine the phase diagram in the disorder-magnetic field plane. Edge-state tunneling spectroscopy will be used to probe microscopic properties and low-energy excitation of various electronic phases. %%% This experimental research project is devoted to basic properties of a conducting electron system when confined in a two-dimensional planar region. Such a confined set of electrons at low temperatures and with high magnetic fields exhibits a very unusual set of characteritics, which are of interest to theorists who wish to test and extend the basic thoery of electrons in crystalline solids. An improved theory then can be applied with more confidence to the wide range of metals and semiconductors which are of importance in microelectronics and other technologies. The experiments in this project are focusing on a "metal-insulator" transiton which ahs been observed and in particular on how it appears in connection with disorder in the environment of the electrons. On the one hand the experiments will provide new basic information about electrons when they are in interaction in confined layers at low temperatures. On the other hand the device structures which are used in these experiments are similar to those used in advanced microelectronic devices in the Gas technology. This research will involve students who will be well trained in the area of physics and will also gain familarity w ith semiconductor device technology, nd who will be excellently trained for employment in industry, government, or education. ***

9705439 Jiang 这个实验研究项目重点关注量子霍尔效应体系中的二维电子气，特别是相图和受无序影响的局域-离域转变。 门控GaAs/AlGaAs器件将用于获得对实验系统的有效无序的控制。 将进行高磁场输运实验，以研究磁场引起的离域转变并确定无序磁场平面中的相图。 边缘态隧道光谱将用于探测各种电子相的微观特性和低能激发。 %%% 该实验研究项目致力于研究限制在二维平面区域中的导电电子系统的基本特性。 这样一组受限的电子在低温和高磁场下表现出一组非常不寻常的特征，这些特征引起了希望测试和扩展晶体固体中电子基本理论的理论学家的兴趣。 然后，改进的理论可以更有信心地应用于在微电子和其他技术中非常重要的各种金属和半导体。 该项目的实验重点关注已观察到的“金属-绝缘体”跃迁，特别是它如何与电子环境中的无序相关。 一方面，这些实验将提供有关电子在低温约束层中相互作用时的新基本信息。 另一方面，这些实验中使用的器件结构与气体技术中的先进微电子器件中使用的器件结构相似。 这项研究将涉及在物理领域接受过良好培训的学生，他们还将熟悉半导体器件技术，并且他们将受到良好的工业、政府或教育就业培训。 ***