Quantum Transport and the Aharonov-Casher Effect in Two Dimensional Electron Gases

这项研究的目的是通过实验表明， 二维电子气中电子自旋的相位可以是 操纵产生量子干涉效应， 电导率; Aharonov预测了这种效应， 1984年的收银员。 在原子强度电场存在的情况下 在锌半导体中，Aharonov-Casher干扰 应该是可以观察到的使用电子磁矩在一个两个 尺寸受限的电子气。 感应相移为 对于可实现的介观，预测为2-10 π弧度 几何学 将在GsAs上定义环形几何形状和Young干涉仪 异质结场效应器件 相位将有所不同 通过电子磁矩对 电子面密度 在零磁场中， 电子传导率的振荡，表面的周期性 电子密度和1/（25812）mhos的量级，将证明 Aharonov-Casher方法的有效性 介观系统的自旋相关性质。 这些 实验对于预测电子 量子点和弹道输运实验中自旋作用 在半导体异质结中实现。 %%% 半导体固体中电子输运的原理有 已经被理解很久了。 在过去的十年里， 说明电子波度的效应已经被 在制造非常小的器件结构时观察到。 这些尺寸 需要电子波长的数量级，大约10 百万分之一米 这些量子点的制造技术 设备起源于对更小设备的要求， 计算机芯片行业。 电子还带有磁矩， 表示为自旋量子数的物理可观测值。 这项研究提出的是寻找方法来操纵 电子波的自旋相位，从而引起干涉。 自旋相位可以随着磁矩移动通过 电场 在这里，内部电场存在于 将开发化合物半导体。 的结果 研究将有助于理解电子自旋在 量子点和弹道传输实验， 异质结和类似的量子器件结构。

The objective of this research is to show experimentally that the phase of the electron spin in a two dimensional electron gas can be manipulated to produce quantum interference effects modulating the electrical conductivity; this effect was predicted by Aharonov and Casher in 1984. With the atomic strength electric fields present in zincblende semiconductors, the Aharonov-Casher interference should be observable using the electron magnetic moment in a two dimensionally confined electron gas. The induced phase shift is predicted to be 2-10 pi radians for realizable mesoscopic geometries. Ring geometries and Young interferometers will be defined on GsAs heterojunction field effect devices. The phase will be varied through the dependence of the electron magnetic moment upon electron surface density. In zero magnetic field the observation of oscillations in the electron conductivity, periodic in surface electron density and of magnitude 1/(25812) mhos, will demonstrate the validity of the Aharonov-Casher approach to the understanding of the spin dependent properties of mesoscopic systems. These experiments will be essential for predicting the role that electron spin plays in quantum dot and ballistic transport experiments implemented in semiconductor heterojunctions. %%% The principles of electron transport in semiconducting solids have been understood for a long time. In the last decade, interference effects illustrative of the wavenature of the electron have been observed when very small device structures are made. These sizes need to be of the order of the electron wavelength, about one ten millionth of a meter. The fabrication technology for these quantum devices originated in the requirements for ever smaller devices in the computer chip industry. The electron also carries a magnetic moment which can be represented as the physical observable of a spin quantum number. The research proposed is to search for methods to manipulate the spin phase of the electron waves such as to cause interference. Spin phase can change as the magnetic moment moves through an electric field. Here the internal electric fields existent in compound semiconductors will be exploited. The results of this research will assist in understanding the role of electron spin in quantum dot and ballistic transport experiments implemented in heterojunctions and similar quantum device structures.