Floquet theory for the electronic stopping of projectiles in solids

TL;DR

This paper introduces a comprehensive Floquet-based theoretical framework to analyze electronic stopping of projectiles in crystalline solids, overcoming limitations of previous models by not relying on perturbative or idealized assumptions.

Contribution

It develops a general, non-perturbative Floquet theory for electronic stopping in solids, applicable to various materials and trajectories, and explains threshold velocity effects in insulators.

Findings

Floquet theory characterizes stationary solutions for projectiles in solids.

The framework recovers previous perturbative and jellium models.

Analysis of threshold velocity effects in insulators is provided.

Abstract

A general theoretical framework for the study of electronic stopping of particle projectiles in crystalline solids is proposed. It neither relies on perturbative or linear response approximations, nor on an ideal metal host. Instead, it exploits the discrete translational symmetries in a space-time diagonal determined by a projectile with constant velocity moving along a trajectory with crystalline periodicity. This allows for the characterisation of (stroboscopically) stationary solutions, by means of Floquet theory for time-periodic systems. Previous perturbative and non-linear jellium models are recovered from this general theory. An analysis of the threshold velocity effect in insulators is presented based on Floquet quasi-energy conservation.