RUI: Novel Transport Properties in Strongly Interacting Electron Systems

RUI：强相互作用电子系统中的新颖输运特性

• 批准号: 0307170
• 负责人: Donna Sheng
• 金额: $ 30万
• 依托单位: The University Corporation, Northridge
• 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: 2003-09-01 至 2007-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0307170&HistoricalAwards=false
• 关键词: RUI; Novel; Transport; Properties; Strongly

This award supports fundamental theoretical and computational research and education on strongly interacting electrons confined to two-dimensions in semiconductors. The PIs will study metal-insulator transitions (MITs). It is generally believed that strong electronic correlations are responsible for both the zero-field MIT in 2D semiconductors and the superconductor-insulator transition in high-Tc superconductors, although there has been no consensus on the microscopic mechanism for either transition. A central goal of this research is to explore whether the zero-field MIT for interacting electrons in 2D has an insightful topological description characterized by the Chern number. Quantum Hall stripe phases will be studied using exact diagonalization and the density matrix renormalization group (DMRG method). An objective is to obtain transport properties using the Chern number description of the wavefunctions and the generalized Thouless number method for many body systems. These calculations are aimed to determine if there is a new liquid-crystal-like metallic phase, a smectic phase, at low temperature. These calculations are intended to elucidate the role played by disorder and quantum fluctuations and to give insight into the nature of these strongly correlated electron systems. The PIs will also use a new method based on the topological characterization of the wavefunction, to study novel transport properties of double layer systems of strongly interacting two dimensional electrons in order to better understand Coulomb drag transport, and longitudinal and transverse spin transport in coupled two layer semiconductor systems. Based on transport properties, the phase diagram and the nature of quantum phase transitions in double layer systems will be determined.This award supports educational experiences for students at California State University Northridge and Sam Houston University enabling them to participate in research. %%%This award supports fundamental theoretical and computational research and education on strongly interacting electrons confined to two-dimensions in semiconductors. The PIs will use an innovative theoretical approach combined with computation to carry out research in three areas, where the PIs will explore: 1.) whether electronic correlations can give rise to a phase transition between metallic and insulating states as the amount of disorder is increased; 2.) whether layered semiconductor systems can be combined in such a way that the interactions between electrons between layers can be manipulated to control the transport of spin and charge in three dimensional semiconductor structures; 3.) the effect of disorder on quantum Hall states of electrons confined to two-dimensions in a strong perpendicular magnetic field. Each of these areas involves fundamental challenges to our understanding of electronic states in materials and involves novel phenomena that arise as a consequence of the correlations among electrons that result from strong electron-electron interactions. This work also contributes to the intellectual foundations for new generations of semiconductor devices. This award supports educational experiences for students at California State University Northridge and Sam Houston University enabling them to participate in research. ***

该奖项支持基本的理论和计算研究和教育，这些电子相互作用的电子局限于半导体的二维。 PI将研究金属 - 绝缘体过渡（MIT）。通常认为，强的电子相关性是2D半导体中的零场MIT和高-TC超导体中的超导体 - 导体 - 绝缘体转变，尽管在微观机制上尚无共识以进行这两种过渡。这项研究的一个核心目的是探索2D中用于相互作用电子的零场MIT是否具有以Chern数为特征的有见地的拓扑描述。将使用精确的对角线化和密度基质重归其化组（DMRG方法）研究量子厅条纹阶段。一个目的是使用Chern数字描述波形的Chern数字描述以及许多人体系统的通用TH数字方法。这些计算旨在确定在低温下是否有一个新的液晶状金属相（晶状体相）。这些计算旨在阐明无序和量子波动所起的作用，并深入了解这些密切相关的电子系统的性质。 PI还将使用基于波函数的拓扑表征的新方法来研究强烈相互作用的二维电子的双层系统的新型传输性能，以便更好地了解库仑阻力传输，以及在两个层半导体系统中耦合的纵向和横向自旋传输。根据运输属性，将确定双层系统中量子相变的性质和量子相变的性质。该奖项支持加利福尼亚州立大学诺斯里奇和萨姆·休斯顿大学的学生的教育经验，使他们能够参与研究。 %%％该奖项支持基本的理论和计算研究和教育，这些电子相互作用的电子局限于半导体的二维。 PI将使用一种创新的理论方法与计算相结合在三个领域进行研究，PIS将探索：1。）电子相关性是否会导致金属和绝缘状态之间的相过渡，并且随着疾病量的增加； 2.）是否可以将分层半导体系统组合起来，以使可以操纵层之间电子之间的相互作用以控制自旋和电荷在三维半导体结构中的运输； 3.）障碍对限制在强垂直磁场中二维的电子量子状态的影响。这些领域中的每一个都涉及我们对材料中电子状态的理解的根本挑战，并涉及由于强烈的电子电子相互作用而导致的电子之间的相关性而产生的新现象。这项工作还为新一代半导体设备的知识基础做出了贡献。该奖项支持加利福尼亚州立大学诺斯里奇大学和萨姆·休斯顿大学的学生的教育经验，使他们能够参加研究。 ***