论文标题
各向异性等离子体
Theroy of anisotropic plasmons
论文作者
论文摘要
在相应的非相互作用情况下，在存在明显的质量（或速度）各向异性的情况下，我们开发了相互作用电子系统的集体等离子模式的完整理论，而有效的费米速度沿不同的轴是不同的。这种有效的质量各向异性在固态材料（例如硅或锗）中很常见，那里的费米表面通常不是球形的。我们发现，等离子体色散本身在此类系统中发展出明显的各向异性，并且使用态密度或光学有效质量的通常使用的各向同性近似对各向异性系统不起作用。我们预测各向异性系统中的一种新现象，没有相应的各向同性类似物，其中一个方向的等离子模式通过Landau阻尼延伸到电子孔对中，而该模式保持不安全和稳定，沿着不同方向稳定
We develop the complete theory for the collective plasmon modes of an interacting electron system in the presence of explicit mass (or velocity) anisotropy in the corresponding non-interacting situation, with the effective Fermi velocity being different along different axes. Such effective mass anisotropy is common in solid state materials (e.g., silicon or germanium), where the Fermi surface is often not spherical. We find that the plasmon dispersion itself develops significant anisotropy in such systems, and the commonly used isotropic approximation of using a density of states or optical effective mass does not work for the anisotropic system. We predict a qualitatively new phenomenon in anisotropic systems with no corresponding isotropic analog, where the plasmon mode along one direction decays into electron-hole pairs through Landau damping while the mode remains undamped and stable along a different directions
