Plasma Oscillations in an Inhomogeneous Electron Gas

本研究的目的是从实验上研究在宽的、远掺杂的AlGaAs异质结中电子气中的等离子体振荡。这种新型的固态等离子体具有空间可调的密度分布和足够高的电子迁移率，为在低于和远高于简并温度(约20K)的温度下观测到明确定义的等离子体提供了机会。这些系统的优点是，限制电子的势能在托马斯-费米屏蔽长度的尺度上是平滑的，这意味着结果可以与不会因块状半导体和金属等离子体中快速变化的强大离子势而复杂化的“凝胶”理论进行比较。PI计划使用可见光散射和远红外光谱来探测电子层中密度梯度对等离子体模式的影响。

The objective of this research is to study experimentally the plasma oscillations in the electron gas confined in wide, remotely-doped AlGaAs heterostructure wells. This novel solid state plasma, with a spatially-tunable density distribution and with sufficiently high elctron mobilities, presents the opportunity to observe well-defined plasmas for temperatures below and well above the degeneracy temperature (approximately 20 K). These systems have the advantage that the potential that confines the electrons is smooth on the scale of the Thomas-Fermi screening length, meaning results can be compared with "jellium" theories that are not complicated by the strong, rapidly varying ionic potentials in bulk semiconductors and metallic plasmas. The PI plans to use visible-light scattering and far-infrared spectroscopy to probe the effects of density gradients in the electron layer on the plasma modes.