Electronic Stopping Power in LiF from First Principles

J M Pruneda,D Sánchez-Portal,Emilio Artacho,J I Juaristi,A Arnau

doi:10.1103/physrevlett.99.235501

Abstract

Using time-dependent density-functional theory we calculate from first principles the rate of energy transfer from a moving proton or antiproton to the electrons of an insulating material, LiF. The behavior of the electronic stopping power versus projectile velocity displays an effective threshold velocity of approximately 0.2 a.u. for the proton, consistent with recent experimental observations, and also for the antiproton. The calculated proton/antiproton stopping-power ratio is approximately 2.4 at velocities slightly above the threshold (v approximately 0.4 a.u.), as compared to the experimental value of 2.1. The projectile energy loss mechanism is observed to be extremely local.

Highlights

The interaction of charged particles with matter has been a subject of extensive research since the discovery of subatomic particles [1]
Experimental results remain unexplained even for simple systems. This is true at low velocities [2,3], where the contribution from nuclear collisions conceals the electronic stopping [4]
The actual interatomic forces could be enormously altered, by the local electron heating produced by the electronic stopping

Summary

Introduction

The interaction of charged particles with matter has been a subject of extensive research since the discovery of subatomic particles [1]. Using time-dependent density-functional theory we calculate from first principles the rate of energy transfer from a moving proton or antiproton to the electrons of an insulating material, LiF.

Results

Conclusion