Experimental Investigations of Properties of Electron Systems

电子系统特性的实验研究

• 批准号: 0243046
• 负责人: Thomas Gramila
• 金额: --
• 依托单位: Ohio State University Research Foundation -DO NOT USE
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-05-01 至 2007-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0243046&HistoricalAwards=false
• 关键词: Experimental; Investigations; Properties; Electron; Systems

The goal of the research supported by this individual investigator grant is to increase our understanding of electron physics. The project has two parts. One seeks to understand a surprising and dramatic behavior of electrons: the sign reversal in a measured transport parameter. This reversal, seen for two-dimensional electrons in magnetic fields smaller than one Tesla, was entirely unanticipated, and remains without explanation. Evidence exists that the unusual behavior is directly related to the electron spin, offering the prospect for new advances in important areas of electron physics. The second part will use a new experimental approach to explore two complex and important influences on electrons: disorder and interactions. These influences have long been established as central to electronic properties; yet a full understanding of their roles, particularly when both are present, remains elusive. This project will use drag to directly measure the electron density fluctuations, thereby investigating the interplay between disorder and electron interactions in electron systems. The insight to be gained through this new approach arises from the substantial difference in density fluctuations theoretically established between the disorder dominated and the interaction dominated regimes. The training provided students involved in this research aims toward answering fundamental questions in the physic of technologically important materials, while involving a wide range of state of the art technical methods. Such training is valuable preparation for academic, government, or industrial scientific careers.This individual investigator award supports research involving basic questions about the properties of electronic materials. Two primary research directions will be examined through experiments. One involves the surprising discovery of new behavior in a regime that had been widely regarded as well understood: two-dimensional electrons in small magnetic fields. Evidence that the spin of the electrons is involved increases the prospect for valuable new understanding. The other research direction involves a new experimental approach applied to a longstanding but fundamental issue of electronic materials: the influences of disorder and of the interactions between electrons. These influences are widely recognized as being of central importance to a broad range of behaviors in electronic materials. Our measurements will provide new insights into this important topic. Complimenting the value of the science investigated here is the value of the training provided to students. The experiments themselves are technically challenging, involving low-noise measurement with complex sample requirements, and the use technologically important materials. They push the boundaries of measurement technology, sample preparation, and even sample growth. The basic research explored in this work offers the prospect of strengthening the intellectual underpinnings of a number of important technological areas, from spin based electronics to ultra-small devices, which rely on a broad understanding of electron physics.

这项研究的目标是增加我们对电子物理的理解。 该项目有两个部分。 人们试图理解电子的一个令人惊讶和戏剧性的行为：在测量的输运参数的符号反转。 在小于1特斯拉的磁场中，二维电子的这种反转是完全没有预料到的，并且仍然没有解释。 有证据表明，这种不寻常的行为与电子自旋直接相关，为电子物理重要领域的新进展提供了前景。 第二部分将使用一种新的实验方法来探索对电子的两种复杂而重要的影响：无序和相互作用。 这些影响长期以来一直被认为是电子性质的核心;然而，对它们的作用，特别是当两者都存在时，仍然难以理解。 该项目将使用拖曳直接测量电子密度波动，从而研究电子系统中无序和电子相互作用之间的相互作用。 通过这种新的方法获得的洞察力来自于理论上建立的无序为主和相互作用为主的制度之间的密度波动的实质性差异。 为参与本研究的学生提供的培训旨在回答技术上重要材料的基本问题，同时涉及广泛的最先进的技术方法。 这种培训对于学术、政府或工业科学事业是有价值的准备。该个人研究者奖支持涉及电子材料特性基本问题的研究。 两个主要的研究方向将通过实验进行检查。 其中之一是在一个被广泛认为已经很好理解的机制中发现了令人惊讶的新行为：小磁场中的二维电子。 电子自旋参与的证据增加了有价值的新认识的前景。 另一个研究方向涉及一种新的实验方法，应用于电子材料的一个长期但基本的问题：无序和电子之间相互作用的影响。 这些影响被广泛认为对电子材料的广泛行为至关重要。 我们的测量将为这一重要主题提供新的见解。为学生提供培训的价值是对这里所研究的科学价值的补充。 实验本身在技术上具有挑战性，涉及低噪声测量和复杂的样品要求，以及使用技术上重要的材料。 它们突破了测量技术、样品制备甚至样品生长的界限。 在这项工作中探索的基础研究提供了前景，加强一些重要的技术领域的知识基础，从基于自旋的电子学到超小型设备，这依赖于对电子物理学的广泛理解。