Quantum electron solids and interaction-driven phenomena in two- and one-dimensional systems

二维和一维系统中的量子电子固体和相互作用驱动的现象

• 批准号: 1410302
• 负责人: Jian Huang
• 金额: $ 37.5万
• 依托单位: Wayne State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1410302&HistoricalAwards=false
• 关键词: Quantum; electron; solids; interaction; driven

Nontechnical: Electrons are tiny quantum mechanical objects that exist in all physical systems and most systems contain a large number of them. Understanding how electrons interact with each other and with the environment is a vital scientific subject and has played a critical role in advancing modern science and technologies. Analogous to water, electrons manifest both gaseous states at high temperatures and liquid states at low temperatures. Another form is a solid state which was predicted but never observed. To obtain evidence of this solid state of electrons is not only important in understanding how the most basic force can radically affect the quantum states, but also allows scientists to develop remarkable future quantum electronics and spintronics. These energy sustainable systems are fundamentally important to nature. With greatly improved semiconductor technologies, a novel type of semiconductors of ultra-high purity has become available as a result of a recent breakthrough and preliminary results have been recently obtained as evidence of a genuine quantum electron solid. This project utilizes such devices to perform experiments with the most advanced scientific tools: nanofabrication and ultra-low temperature physics. The goal is to capture the direct evidence for the quantum mechanical mechanisms in the dynamical properties. This project supports the education of one Ph.D. student in pursuing discovery and advanced technologies, and allows the group to conduct outreach activities with local high schools. Technical: Remarkable new quantum phenomena, such as the even-denominator Fractional Quantum Hall Effect and Topological Insulators, emerge in response to strong inter-particle Coulomb interaction. However, the most prominent interaction-driven effect, Wigner crystallization of electrons, has not been well established. This fascinating quantum matter (with spin ordering) is not only paramount to fundamental science, but also important for future applications including quantum electronics and spintronics. For a long time, experimental effort was hindered because most devices contain a high level of unwanted disorder which overwhelms the interaction effect at low electron densities. Since 2003, breakthroughs have been made in providing ultra-high quality two-dimensional electron systems in GaAs semiconductor field-effect-transistors. Recent achievement with the measurement of ultrahigh purity GaAs field-effect transistors (named HIGFET) has led to the observation of a genuine WC. Moreover, the preliminary results also point to possible quantum pinning/depinning mechanisms that are not understood. This project utilizes these types of devices with record low electron densities to perform transport experiments at mK temperatures. The goal is to verify the quantum nature of the dynamical properties well below the classical limits. Various techniques such varying temperature, density, and interaction are adopted to study the phase boundaries. AC+DC excitation technique is utilized to directly probe the collective, large-scale quantum tunneling in a Wigner Crystal. This project supports the education of one Ph.D. student in pursuing discovery and in learning advanced technologies, which are indispensable for excellent training in pursuing scientific careers.

非技术性：电子是所有物理系统中存在的微小量子机械对象，并且大多数系统都包含大量它们。了解电子如何相互互动以及与环境是一个至关重要的科学主题，并且在推进现代科学和技术方面发挥了关键作用。类似于水，电子在高温下在高温下表现出气态状态。另一种形式是预测但从未观察到的固态。为了获得这种固态电子状态的证据，不仅在理解最基本的力量如何从根本上影响量子状态的情况很重要，而且还允许科学家开发出显着的未来量子电子和旋转型。这些能源可持续系统对自然至关重要。 随着半导体技术的大大改进，由于最近的突破和初步结果，已获得了一种新型的超高纯度半导体类型，作为真正的量子电子固体的证据。该项目利用此类设备可以使用最先进的科学工具进行实验：纳米制作和超低温度物理。目的是捕获动力学特性中量子机械机制的直接证据。该项目支持一所博士学位的教育。学生追求发现和高级技术，并允许小组与当地高中进行外展活动。技术：显着的新量子现象，例如均匀的分数量子霍尔效应和拓扑绝缘子，响应强烈的粒子间库仑相互作用而出现。 但是，最突出的相互作用驱动的效应，电子的智慧结晶尚未得到很好的确定。这种引人入胜的量子物质（带有旋转顺序）不仅对基本科学至关重要，而且对于包括量子电子和旋转的未来应用也很重要。长期以来，由于大多数设备都包含高水平的不良疾病，这会阻碍实验性的努力，从而使低电子密度下的相互作用效果不堪重负。自2003年以来，在GAAS半导体野外效应 - 传播器中提供超高质量的二维电子系统方面取得了突破。通过测量超高纯度GAAS场效应晶体管（名为Higfet）的最新成就导致了真正的WC的观察。此外，初步结果还指出了尚不清楚的可能的量子固定机制。该项目利用这些类型的设备具有创纪录的低电子密度来在MK温度下进行运输实验。目标是验证远低于经典限制的动力学特性的量子性质。采用了各种技术，例如温度，密度和相互作用来研究相边界。 AC+DC激发技术用于直接探测Wigner晶体中的集体大规模量子隧道。 该项目支持一所博士学位的教育。学生追求发现和学习高级技术，这对于从事科学职业的出色培训是必不可少的。