Physics of Strongly Correlated Two Dimensional Electron Systems

这是一个凝聚态物理实验项目，旨在提高我们对先进半导体异质结构中二维电子系统集体行为的理解。重点将放在高磁场和极低温下的电输运、量子隧穿和库仑阻力测量上。这些探针将应用于新发现的高激发朗道能级的多电子态，以及双层系统中二维电子所表现出的显著铁磁构型。这些实验的结果将有助于阐明这些不寻常物质相的基本结构（例如相关液体、电荷密度波等）。由于量子多体问题是现代凝聚态物理的核心问题，计划中的研究将具有广泛的意义。由于只有非常纯净的半导体样品适合于这项研究，因此可以预期对先进晶体生长的材料科学产生积极影响。该研究为研究生和博士后提供了良好的教育机会，他们将在学术界、工业界或政府部门接受职业培训。他们的工作涉及基础物理和接触尖端材料和仪器。这个实验凝聚态物理项目旨在提高对技术上重要的半导体材料中大量电子行为的基本理解。计划中的研究将有几个结果：首先，电子系统本身的基本性质将被阐明。注意力将集中在那些关键地依赖于电子相互施加的排斥力的方面。这种“多体问题”是现代凝聚态科学的核心。其次，这项研究将推动材料科学的前沿。这项工作所需的样品需要最先进的晶体生长方法来制造，并且最终必须具有最高的纯度和复杂性。这些相同的生长方法被用于制造各种各样的技术上重要的设备，从移动电话的快速晶体管到光盘播放器的激光器。这项研究有很强的教育成分，将有助于国家的技术竞争力。

This is a condensed matter physics experimental project aimed at improving our understanding of the collective behavior of two-dimensional electron systems in advanced semiconductor heterostructures. Attention will be focused on electrical transport, quantum tunneling, and Coulomb drag measurements at high magnetic field and very low temperature. These probes will be applied to the newly discovered many-electron states in highly excited Landau levels and to the remarkable ferromagnetic configurations that two-dimensional electrons in double layer systems exhibit. The results of these experiments will help to elucidate the underlying structure (e.g. correlated liquid, charge density wave, etc.) of these unusual phases of matter. As the quantum many-body problem is at the heart of modern condensed matter physics, the planned research will have broad significance. A positive impact on the materials science of advanced crystal growth can also be expected since only the very purest semiconductor samples are suitable for this research. The research provides excellent educational opportunities for graduate students and post-doctoral associates who be trained for careers in academe, industry or government. Their work involves fundamental physics and exposure to cutting edge materials and instrumentation.%%%This experimental condensed matter physics project is aimed at improving the basic understanding of how large groups of electrons behave in technologically important semiconductor materials. The planned research will have several outcomes: First, the fundamental properties of the electron systems themselves will be elucidated. Attention will be focussed on those aspects that depend critically on the repulsive forces the electrons exert upon one another. This "many-body problem" is at the core of modern condensed matter science. Second, this research will advance the frontiers of materials science. The samples needed for this work require the most advanced methods of crystal growth for their fabrication and, in the end, must be of the very highest purity and complexity. These same growth methods are used to fabricate a wide variety of technologically important devices, ranging from fast transistors for cellular telephones to lasers for compact disk players. This research has a strong educational component and will contribute to the Nation's technological competitiveness.