Experiments on Fractional Quantum Hall Effect and Related Physics in New Regimes

在现代电子学中，几乎所有的器件功能都是由电子执行的，这些电子被限制在薄膜中或沿着半导体的界面运动。这种所谓的二维(2D)电子系统在正常环境下表现为一种普通的2D粒子气体，当它们受到低温(T1K)和强磁场(B1T)的极端条件影响时，就演变成了一个新的物理前沿。观察到的一些物理现象是早期理论预测的首次实现(例如维格纳晶体和天空微子)；其他一些现象，如复合费米子，则是较新的发现和发明。所有这些都代表了在量子力学原理中表现出来的超低能级物理，这些原理支配着固态中大量强相互作用电子的行为。该项目将在以前无法进入的低电子密度和超低温的物理体系中探索这种超低能电子物理，直到1MK以下。这些实验旨在发现这些制度中的新量子相并探索其量子相变，预计还将在两个具有社会重要性的领域产生更广泛的影响：一个是教育和培训具有多学科知识和视角的未来科学技术领导者，以及尖端技术技能。这项研究是多学科的，将教育参与的学生和博士后流利地掌握凝聚态物理、半导体材料科学和半导体器件的加工技术。另一个领域是未来的量子计算机。目前对容错量子计算机的设想是使用非阿贝尔粒子。到目前为止，这种粒子在固态中唯一已知的实现是由2D电子介质中发现的成对复合费米子的奇异液体凝聚的准粒子。在现代电子学中，几乎所有的器件功能都是由电子执行的，这些电子可以在薄膜中或沿着半导体的界面在二维中自由运动。这种所谓的二维(2D)电子在正常环境中的行为就像是由独立的2D粒子组成的普通气体。它们中的许多粒子在一起的行为就是单个粒子的总和，每个粒子都得到了经典物理定律的充分描述。然而，当受到极低的温度和高磁场的影响时，它们成为超低能级物理的新前沿，出人意料地富含新的相，这些相体现了量子物理的工作原理，这些量子物理控制着固体中大量强相互作用电子的行为。这个项目将探索在以前无法进入的低电子密度和低温物理体系中的超低能电子物理。这应该会发现电子的新量子相，在那里它们被描绘成一种新的奇异液体或固体更合适，并探索它们的转换。预计它还将对具有多学科知识和观点以及尖端技术技能的未来科学技术领导人的教育和培训产生更广泛的影响。这项研究是多学科的，将教育参与的学生和博士后流利地掌握凝聚态物理、半导体材料科学和半导体器件的加工技术。

In modern day electronics, almost all device functions are performed by electrons that are confined to move in thin films, or along the interfaces, of semiconductors. Such so-called two-dimensional (2D) electron systems, which behave at normal ambient as an ordinary gas of 2D particles, evolve into a new frontier of physics when they are subjected to the extreme conditions of low temperatures (T1K) and high magnetic fields (B1T). Some of the observed physical phenomena are first realizations of early theoretical predictions (e.g. the Wigner crystal and the skyrmion); others, such as composite fermions, are more recent discoveries and inventions. All represent the ultra-low energy physics manifested in the quantum mechanical principles that govern the behavior of large numbers of strongly interacting electrons in the solid state. This project will explore such ultra-low energy electron physics in previously inaccessible physical regimes of low electron densities and ultra-low temperatures, to below 1 mK. The experiments, designed to uncover new quantum phases in these regimes and to probe into their quantum phase transitions, are also expected to have broader impacts in two areas of societal importance: One is in the education and training of future leaders in science and technology with multi-disciplinary knowledge and perspectives, as well as cutting edge technical skills. The research, being multi-disciplinary in nature, will educate students and post-docs involved to be fluent in condensed matter physics, the science of semiconductor materials, and the processing technology of semiconductor devices. The other area is on the future quantum computer. The current vision for a fault-tolerant quantum computer is the one that uses nonAbelian particles. To date, the only known realization of such particles in the solid state consists of the quasi-particles of the exotic liquid condensate of paired composite fermions found in 2D electron media.In modern day electronics, almost all device functions are performed by electrons that are free to move in two dimensions in thin films, or along the interfaces, of semiconductors. Such so-called two-dimensional (2D) electrons behave at normal ambient as an ordinary gas of independent 2D particles. The behavior of a large number of them together is simply that of the sum of the individual particles, each adequately described by the classical law of physics. However, when subjected to extremely low temperatures and high magnetic fields, they become a new frontier for ultra-low energy physics, surprisingly rich in novel phases that manifest the workings of quantum physics that govern the behavior of a large number of strongly interacting electrons in the solid. This project will explore ultra-low energy electron physics in previously inaccessible physical regimes of low electron densities and low temperatures. This should uncover new quantum phases of the electrons, where they are more appropriately pictured as a new kind of exotic liquid or solid, and to probe their transformations. It is also expected to have broader impacts in the education and training of future leaders in science and technology with multi-disciplinary knowledge and perspectives, as well as cutting edge technical skills. The research, being multi-disciplinary in nature, will educate students and post-docs involved to be fluent in condensed matter physics, the science of semiconductor materials, and the processing technology of semiconductor devices.