Thermodynamic Measurements of Interacting Disordered Quantum Hall Systems

相互作用的无序量子霍尔系统的热力学测量

• 批准号: 0071969
• 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: 2000
• 资助国家: 美国
• 起止时间: 2000-08-01 至 2004-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0071969&HistoricalAwards=false
• 关键词: Thermodynamic; Measurements; Interacting; Disordered; Quantum

Jiang0071969This research is focused on the thermodynamic measurements of interacting disordered semiconductor heterostructures. The problem of strong correlations, in low-dimensional quantum systems, is made more difficult by the presence of disorder. Particularly, the thermodynamic properties of interacting disordered quantum Hall devices is still poorly understood. A high density GaAs/AlGaAs quantum well structure with two populated subbands as well as a p-type single-heterostructure with highly correlated holes will be used for the investigations. Compressibility will be measured by using a field-penetration technique to probe the internal interaction energy. Magnetization will be measured by a torsional magnetometer to determine the spin polarization at different electronic phases. Various physical regimes will be explored following the "road-maps" obtained from early transport studies. Electrically controlled gates will be used to vary the density, to alter the screening properties, and to change the spatial correlation of the disorder. Contemporary issues, such as the nature of the zero-field 2D metal-insulator transition, its relation to quantum Hall effect, and consequences of Landau level interactions in two-component systems, will be addressed. This project will also provide an excellent training for graduate and undergraduate students in this program for solid state electronics field. In fact, the semiconductor device fabrication and characterization aspects of the work overlaps closely with what is going on right now in semiconductor electronics industry.%%%This project is concentrated on the study of thermal properties of thin-layered semiconductor structures in the presence of both disorder and carrier interaction. Similar structures are currently used for high-speed electronics and opto-electronics technologies. Due to the intricate interplay of disorder and interaction, the properties of these advanced devices are less predictable, and sometimes even appear to be mysterious. The proposed experiments study the thermal properties of several poorly understood quantum electronic phases by using several high-sensitivity measurement techniques. The main objective is to establish a better understanding on the underlying physical principle of these phases and the wealth of effects exhibited. The better understandings can, in turn, provide a basis for designing the next generation of electronics. The concepts obtained from the proposed experiments can be applied to some of the more complex condensed matter systems. The work concerning electron spins could potentially have impact on the development of future quantum information processing systems for quantum computing and quantum communications. This project will also provide an excellent training for graduate and undergraduate students in this program for solid state electronics field. In fact, the semiconductor device fabrication and characterization aspects of the work overlaps closely with what is going on right now in semiconductor electronics industry.

Jiang0071969这项研究的重点是相互作用的无序半导体异质结构的热力学测量。 在低维量子系统中，强相关性问题由于无序的存在而变得更加困难。 特别是，相互作用的无序量子霍尔器件的热力学性质仍然知之甚少。 具有两个填充子带的高密度 GaAs/AlGaAs 量子阱结构以及具有高度相关空穴的 p 型单异质结构将用于研究。 压缩性将通过使用场穿透技术探测内部相互作用能来测量。 磁化强度将通过扭转磁力计测量，以确定不同电子相位的自旋极化。 根据早期交通研究获得的“路线图”，将探索各种物理状况。 电控门将用于改变密度、改变筛选特性以及改变无序的空间相关性。 当代问题，例如零场二维金属-绝缘体转变的性质、其与量子霍尔效应的关系以及二元系统中朗道能级相互作用的后果，将得到解决。 该项目还将为固态电子领域的研究生和本科生提供良好的培训。 事实上，半导体器件制造和表征方面的工作与半导体电子行业目前正在发生的事情密切重叠。%%%该项目集中于研究薄层半导体结构在存在的情况下的热性能紊乱和载体相互作用。 类似的结构目前用于高速电子和光电子技术。 由于无序和相互作用错综复杂的相互作用，这些先进设备的特性难以预测，有时甚至显得神秘。 所提出的实验通过使用几种高灵敏度测量技术来研究几种人们知之甚少的量子电子相的热性质。 主要目标是更好地理解这些阶段的基本物理原理以及所表现出的丰富影响。 更好的理解反过来可以为设计下一代电子产品提供基础。 从所提出的实验中获得的概念可以应用于一些更复杂的凝聚态物质系统。 有关电子自旋的工作可能会对未来用于量子计算和量子通信的量子信息处理系统的发展产生影响。该项目还将为固态电子领域的研究生和本科生提供良好的培训。 事实上，半导体器件制造和表征方面的工作与半导体电子行业目前正在发生的事情密切重叠。