Abstracts Category : Other

Theoretical understanding and calculation of the Edelstein effect

by Gustav Eriksson

The main topic of this project is the so called Edelstein effect. This recently discovered effect consists in the possibility of converting an electric field (a current) into a magnetization in materials that fulfill specific characteristics, more specifically materials where an effective Rashba spin-orbit coupling is present. The Edelstein effect is appealing to the scientific community from the fundamental physics point of view as well as from the technological point of view. In fact the possibility of efficiently converting an electric signal into a magnetic signal could revolutionize the current information storage technology. In this project, after a study of basic concepts of solid state physics: crystal structure, Bloch's theorem, spin-orbit coupling; we addressed the study of the basics of a powerful numerical tool, called density functional theory (DFT), for predicting the electronic properties of solids. This tool provides us with all the needed quantities for numerically calculating any kind of linear response, which we show that the Edelstein effect is a specific form of. Using a specific implementation of DFT, called augmented spherical wave (ASW), we calculate the Edelstein effect in iron and copper (where no effect is expected) and manganese silicide (where the effect is expected to appear). We also perform a systematic study on how the Edelstein effect depends on the symmetry of the material and the magnitude of the spin-orbit coupling. The calculations showed promising results from which we concluded that the numerical methods used could clearly distinguish between the presence of the Edelstein effect or not in mentioned materials.