Plasma Oscillations in an Inhomogeneous Electron Gas

本研究的目的是通过实验研究限制在宽的、远程掺杂的 AlGaAs 异质结构阱中的电子气中的等离子体振荡。 这种新型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，提供了在低于和远高于简并温度（大约 20 K）的温度下观察明确等离子体的机会。 这些系统的优点是，限制电子的势在托马斯-费米屏蔽长度的范围内是平滑的，这意味着结果可以与“果冻”理论进行比较，该理论不会因块状半导体和金属等离子体中强大的、快速变化的离子势而变得复杂。 PI 计划使用可见光散射和远红外光谱来探测电子层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.