Electrons in Two-Dimensional Systems

9402647 Dahm技术摘要：将使用半导体异质结构和氦薄膜上的电子来研究二维电子的性质。研究将在门控异质结中的可变范围跳跃区域中进行。我们将在态密度中寻找一个预测的库仑间隙。我们将研究磁场对局域化长度的依赖关系，以测量“浮动”离域态的能量。研究了电子晶体钉扎在液氦薄膜上的导电特性。这是一个模型滑动电荷密度波，与“杂质”(衬底电势)耦合，可以通过改变薄膜厚度在很大范围内改变。非技术摘要：这项研究的目的是更好地理解支配二维系统的物理定律。研究范围从氦表面的经典电子系统到半导体中电子的量子极限。半导体中二维电子的研究与二维霍尔效应密切相关，这项研究的结果可能会应用于电子器件。氦表面上的电子形成了一个模型系统，用来研究在更有限的变量集合中发生的三维现象的性质。***

9402647 Dahm Technical abstract: The properties of electrons in two dimensions will be investigated using semiconductor heterostructures and electrons on helium films. Studies will be carried out in the variable-range hopping regime in gated heterostructures. A search will be made for a predicted Coulomb gap in the density of states. The magnetic field dependence of the localization length will be studied in an attempt to measure the energy of the "floating" delocalization states. The conduction properties of a pinned electron crystal on a liquid helium film will be carried out. This is a model sliding charge-density wave with a coupling to "impurities" (substrate potentials) which can be varied through a wide range by changing the film thickness. Non-technical abstract: The aim of this study is to achieve a better understanding of the laws of physics governing two- dimensional systems. The investigations span the spectrum of interest from a classical system of electrons on a helium surface to the quantum limit of electrons in semiconductors. The study of two-dimensional electrons in semiconductors is closely related to the 2D Hall effect and results from this study may have applications to electronic devices. Electrons on a helium surface form a model system to study properties of phenomena which occur in three dimensions within a more limited set of variables. ***