Plasmon damping rates in Coulomb coupled 2D layers in a heterostructure.*

Coulomb excitations due to charge density oscillation are calculated for a double layer

heterostructure. Specifically, we consider two-dimensional (2D) layers of silicene and graphene

on a substrate. The essential ingredient in our calculations is the obtained surface response

function which we employ to calculate the plasmon dispersion relations as well as the decay rate due

to Landau damping. The Coulomb coupling between layers renormalizes the plasmon frequency on a

single layer. Additionally, the single-particle excitations from both layers can contribute to the damping

rates of the plasmon modes.