Demonstration of Exchange Induced Instability in Quantum Wire Structures

9312195鲁登未来的电子技术将依赖于工作原理与当前设备非常不同的电子设备。随着临界尺寸缩小到所谓的介观范围，量子相干和隧穿等现象将主导可能只包含少量电子的结构的特征。这一提议的基本愿景是，纳米结构之间的电子转移和这些结构内电子通过库仑相互作用的耦合对于未来可能的应用至关重要，例如高速随机存取存储器。电子在紧密间隔的纳米结构中的一种耦合机制，特别是量子线，是由于波函数重叠，即隧道效应。第二种耦合机制涉及电子之间的库仑相互作用和相关的交换相互作用。我们的主要目标是--演示和分析当两条量子线放置在很近的地方，从而产生强耦合时发生的新现象。-探索基于耦合量子线中的不稳定性的计算或数据存储的新概念，这些不稳定性最近由Wu和Ruden以及Gold独立预测。提出的研究包括量子结构理论、材料生长、纳米器件制造和广泛的表征工作。特别是，我们将从实验和理论上探索III-V半导体异质结中量子线的电子结构和输运性质。***

9312195 Ruden Future electronics technology will rely on electronics devices whose principles of operation are very different from those of current devices. As the critical dimensions shrink into the so-called mesoscopic range, phenomena such as quantum coherence and tunneling will dominate the characteristics of structures which may contain only few electrons. It is the underlying vision of this proposal that the transfer of electrons between nanostructures and the coupling of the electrons within these structures via Coulomb interactions are of crucial importance for possible future applications, e.g. high speed random access memory. One coupling mechanism of the electrons within closely spaced nanostructures, and specifically quantum wires, is due to wavefunction overlap, i.e. tunneling. A second coupling mechanism involving the Coulomb interaction between the electrons and the associated exchange interaction. Our primary goals are -to demonstrate and anayze new phenomena that occur when two quantum wires are placed in close proximity so that there is strong coupling. -to explore new concepts for computation or data storage based on instabilities in coupled quantum wires that were recently predicted independently by Wu and Ruden and by Gold. The reseach proposed includes work on the theory of quantum structures, on materials growth, nanoscale device fabrication, and extensive characterization. In particular, we will explore experimentally and theoretically the electronic structure and transport properties of quantum wires in III-V semiconductor heterostructures. ***