First-principles theory of low-energy electron diffraction and quantum interference in few-layer graphene

TL;DR

This paper introduces an efficient computational method combining density-functional theory with electron reflectivity calculations to analyze quantum interference effects in few-layer graphene, aligning well with experimental observations.

Contribution

It presents a novel approach to accurately simulate low-energy electron diffraction in graphene using a practical DFT-based method.

Findings

Quantum interference effects in graphene reflectivity are well reproduced

Moderate slab thickness suffices for accurate simulations

Method enhances understanding of electron scattering in layered materials

Abstract

We present a computationally efficient method to incorporate density-functional theory into the calculation of reflectivity in low-energy electron microscopy. The reflectivity is determined by matching plane waves representing the electron beams to the Kohn-Sham wave functions calculated for a finite slab in a supercell. We show that the observed quantum interference effects in the reflectivity spectra of a few layers of graphene on a substrate can be reproduced well by the calculations using a moderate slab thickness.