基底性质对二维层状电子气感应电场的影响

Effects of substrate property on induced electric field of layered two-dimensional electron gases

采用线性化量子流体动力学模型,研究了载能粒子与二维层状电子气相互作用时的集体静电激发现象。在适当的边界条件下推导出感应电势,入射粒子所受的阻止力和侧向力的一般表达式,讨论了存在绝缘基底情况下基底介电常数对感应电势、阻止力及侧向力的影响。结果表明:当入射粒子速度较小时,基底的极化电场较弱,其介电常数的变化对感应电场几乎无影响,而当速度较高时因极化电场较强而影响很大;入射粒子距离与基底相连的电子气平面越近,基底介电常数对各物理量的影响越大。

The collective electric excitations in layered two-dimensional electron gases supported by an insulating substrate induced by a moving charged particle are investigated using linearized quantum hydrodynamic （LQHD） theory. General expres sions of the induced potential, the stopping and image forces acting on the incident particle are derived by selecting appropriate boundary conditions. The influence of dielectric constant on induced potential, the stopping and image forces is discussed. Numer ical results indicate that the substrate property has little influence on the induced electric field at smaller incident particle speed due to the weaker polarized electric field but the influence is remarkable at higher speed due to the stronger polarized electric field the smaller the distance between the incident charged particle and the electron gas plane connected to the substrate, the more the in fluence of dielectric constant on relevant physics properties.