Difração de elétrons em meios bidimensionais isotrópicos e anisotrópicos

Abstract

Diffraction is a wave phenomenon that occurs when a wave passes through an obstacle or slit and spreads out in multiple directions. The scenario where both the screen and the source are at a large distance relative to the obstacle is called Fraunhofer diffraction. Motivated by (i) the wide variety of two-dimensional materials that exhibit anisotropic electronic and transport properties, such as black phosphorus, and (ii) the influence of anisotropy on ballistic transport in these systems and on wave phenomena, like diffraction and interference, we will investigate Fraunhofer diffraction for electrons in anisotropic two-dimensional media, comparing the results with those obtained in the usual isotropic case. The study will evaluate systems composed of single and multiple slits. A semiclassical approach will be employed, with anisotropy introduced through different effective masses along the x and y directions. Results for the probability density at different rotation angles between the coordinate systems and the crystallographic axes of the two-dimensional anisotropic system will be investigated and compared with the recently reported findings published by F. R. V. Araújo et al. in the paper “Single- and double-slit electron diffraction in an anisotropic two-dimensional medium”. (Araújo et al., 2024)