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MA: Fachverband Magnetismus

MA 33: Surface Magnetism II (jointly with O)

MA 33.6: Vortrag

Mittwoch, 9. März 2016, 16:30–16:45, H31

New approach to determine the microscopic interatomic Dzyaloshinskii-Moriya parameters from DFT calculations — •Markus Hoffmann, Bernd Zimmermann, and Stefan Blügel — Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, D-52425 Jülich, Germany

The Dzyaloshinskii-Moriya interaction (DMI) is the key ingredient for the formation of so-called chiral magnetic skyrmions – topological magnetization solitons – in materials with broken structure inversion symmetry. Realistic extended Heisenberg Hamiltonians obtained from a mapping of density functional theory (DFT) calculations provide theoretical insight into the DMI and are the starting point for the investigation of the thermodynamics and spin-dynamics of skyrmions in real chiral magnets. Sofar most DFT calculations provided either micromagnetic DM-vectors or microscopic DM-vectors but of limited interaction range between the magnetic atoms. This prohibits for example the analysis of frustration in the DMI or the consequence of Fermi surface nesting on the DMI. Here, we present a generalization of the derivation of interatomic exchange interactions in ferromagnets [1] to the interatomic DMI in chiral magnets. Applying the magnetic force theorem in a spin-spiral state and calculating D^→(q^→) in the full Brillouin zone, the DMI vectors D_ij^→ can be found via Fourier transformation. We present the analytical expressions relating D_ij^→ to the single-particle energies and apply our new approach to 2Fe/W(110), a commonly studied system in the field of surface magnetism.

[1] M. Ležaić et al., Phys. Rev. B 88, 134403 (2013).