Time-dependent density-functional theory simulation of electron wave-packet scattering with nanoflakes

Abstract

Low-energy electron scattering with nanoflakes is investigated using a time-dependent density functional theory (TDDFT) simulation in real time and real space. By representing the incident electron as a finite-sized wave packet, we obtain diffraction patterns that show not only the regular features of conventional low-energy electron diffraction (LEED) for periodic structures but also special features resulting from the local atomic inhomogeneity. We have also found a signature of $\ensuremath{\pi}$ plasmon excitation upon electron impact on a graphene flake. The present study shows the remarkable potential of TDDFT for simulating the electron scattering process, which is important for clarifying the local and periodic atomic geometries as well as the electronic excitations in nanostructures.