Interactions of the external charged particle beams with double-layer two-dimensional electron gases separated by insulating medium

ABSTRACT

The interactions of a fast-moving charged particle with two parallel layers, each containing a two-dimensional electron gas (2DEG), which are separated by an insulating material, are investigated by the linearized quantum hydrodynamic model describing plasmon excitations in the 2DEGs. We derive general expressions for the perturbed electron density and the induced potential, as well as the image and stopping forces acting on the charged particle moving parallel to the 2DEGs. The results of our calculations indicate that the value of the dielectric constant of the insulating medium exerts a strong influence on those physical quantities. An asymmetric wake effect appears in both the perturbed electron density and the induced potential, showing a decrease in the amplitude of oscillations and an increase in their wavelength with increasing dielectric constant. A double-peak structure appears in the velocity dependence of the image and stopping forces, which arises due to the plasmon hybridization between the 2DEGs, dependent on the value of the dielectric constant in the insulating medium.

KEYWORDS:

• Plasmon
• wake effect
• stopping power
• image force
• 2D materials

PACS:

• 71.10.Ca
• 05.60.Gg
• 34.50.Bw

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Inner Mongolia Autonomous Region Talent Development Fund [Grant Number 2016-149] and Inner Mongolia Autonomous Region Overseas Students Science and Technology Activity Project [Grant Number 2014-350]. Z.L.M. also acknowledges support from the Natural Sciences and Engineering Research Council of Canada [Grant Number 2016-03689].