Manipulating topological spin textures in multiferroic and polar materials

摘要

The possibility to manipulate spin textures is of central importance for their utilisation in functional materials. Here it will be shown how the resulting changes in the spin texture of the electronic structure can directly be imaged by spin- and angle-resolved photoemission spectroscopy (SARPES) by the examples of a multiferroic and a polar material. By using operando SARPES it will be shown that it is possible to reverse both the Rashba-and Zeeman-type spin textures in multiferroic Ge_(1-x)Mn_xTe thin films by applying an external electric field in a capacitor type set-up. Furthermore, by growing homoepitaxial thin films of SrTiO3(001) the filling of the 2D electron gas found in this system can be altered to achieve a single spin-polarised Fermi surface. Combined with the superconducting properties found in SrTiO_3 this Fermi surface topology can form the starting point for the search of Majorana-type excitations.