Berlin 2015 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
TT: Fachverband Tiefe Temperaturen
TT 110: Superconductivity: Fe-based Superconductors – Theory
TT 110.2: Vortrag
Freitag, 20. März 2015, 09:45–10:00, H 2053
Magnetic and orbital ordering in the iron-based superconductors: role of spin-orbit coupling — •Felix Ahn1, Johannes Knolle2, Rafael Fernandes3, and Ilya Eremin1 — 1Institut für Theoretische Physik III, Ruhr-Universität Bochum, D-44801 Bochum, Germany — 2Max Planck Institute for the Physics of Complex Systems, D-01187 Dresden, Germany — 3School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455, USA
We analyze the magnetic ordering in the iron-based superconductors in presence of spin-orbit coupling. Based on several tight-binding parametrizations of the 3d electron states we show how the spin-orbit coupling introduces the anisotropy of the magnetization of the striped antiferromagnetic state by lifting the degeneracy of all three components of the magnetization mx, my and mz. The orientation of the magnetic moment is determined by the contribution of the xy, xz, and yz orbitals to the electronic states near the Fermi level of the electron and hole bands and is determined by the electron filling. We find that within an itinerant approach the magnetic ordering is most favorable along the wavevector of the striped AF state. This appears to be a natural consequence of the spin-orbit coupling in the striped AF state where the ferro-orbital order of the xz and yz orbitals is only a consequence of the striped AF order. We further analyze the role of spin-orbit coupling for the C4 magnetic structure where SDW order parameters with both wavevectors, Qx = (π,0) and Qy=(0,π), coexist.