Noise in a Two Dimensional Electron Gas

该项目的主要目标是研究在强电场存在下二维（2-D）电子气体的噪声特性，即当电子与晶格失去平衡时。这个主题很重要，因为噪声决定了半导体器件的灵敏度和可靠性。这些设备的小型化将导致对二维电子气体的强调，而不是三维电子气体。在本工作中，我们将使用玻尔兹曼输运方程和蒙特卡罗方法来模拟二维电子气体中的电流波动（噪声）。通过计算电流-电流相关函数的时间依赖性，可以确定电流波动及其频率依赖性。噪声是由散射过程定义的。我们将研究局域声子和界面声子对噪声的贡献。特别注意由背景电位和远离子杂质引起的散射。这些杂质状态捕获和随后的释放将被检查；我们预计这些过程将对高电场区域的噪声做出主要（通常是压倒性的）贡献。重点将放在二维结构的低噪声配置的优化。

The main goal of this project is to investigate the noise characteristics of a two-dimensional (2-D) electron gas in the presence of a strong electric field , i.e., when electrons are out of equilibrium with the lattice. This topic is important because noise defines the sensitivity and reliability of semiconductor devices. The miniaturization of these devices will lead to an emphasis on 2-D as opposed to 3-D electron gas. In the present work we will use the Boltzmann transport equation and the Monte Carlo method to simulate current fluctuation (noise) in a 2-D electron gas. By calculating the time dependence of the current- current correlation function it is possible to determine the current fluctuation and its frequency dependence. Noise is defined by scattering processes. We will study the contribution of localized and interface phonons to the noise. Special attention will be paid to scattering by the electric potential of background and remote ionized impurities. Capture by these impurity states and subsequent release will be examined; we expect that these processes will make major (and often overwhelming) contributions to noise in the high electric field region. Emphasis will be placed on the optimization of low-noise configurations for 2-D structures.