Energy loss of charged particles in anisotropic 2D materials using the oscillator model.

We apply the oscillator model to study the energy loss processes of external charged particles interacting with a 2D material characterized by an anisotropic conductivity tensor. We model the material as a monolayer of harmonic oscillators, with anisotropic electronic vibration modes. We focus on the cases of parallel and perpendicular trajectories of the external particle, and we obtain analytical expressions for the stopping power and total energy loss in terms of reduced variables. This allows us to analyze in detail the interaction and to adapt the model to the considered material using adequate values for the physical parameters involved.