Dresden 2017 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 3: Magnetic Textures: Statics and experimental imaging

MA 3.8: Vortrag

Montag, 20. März 2017, 11:30–11:45, HSZ 101

Multiscale model for the chiral magnet FeGe — •Sergii Grytsiuk, Markus Hoffmann, Bernd Zimmermann, Gustav Bihlmayer, Nikolai S. Kiselev, and Stefan Blügel — Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany

The formation of non-collinear spin textures in noncentrosymmetric cubic B20 materials, such as germanides and silicides, developed into a fascinating topic over the past decade also due to their potential for skyrmion-based memory devices. Further studies of skyrmion properties require precise Heisenberg exchange and Dzyaloshinskii-Moriya interaction parameters entering advanced spin models. We calculate these parameters using density functional theory (DFT), focusing on the FeGe alloy. Among the B20 compounds it has the highest Curie temperature and a helical propagation vector of 70 nm, resulting in a B-field in a skyrmion structure of about the same size. Moreover, spin-fluctuations for FeGe, which are difficult to catch with DFT, are much less important than for e.g. MnSi. We use a multiscale approach combining ab initio results, spin dynamics and Monte Carlo simulations to investigate properties of skyrmions in the presence of a magnetic field and electric current. In addition, we extend our studies of chiral magnetism of FeGe from the bulk to thin films where skyrmions are stabilized in a much wider range of temperatures and fields.

Simulations were performed with computing resources granted by JARA-HPC from RWTH Aachen University under project jara0161 and FZJ under projects JIAS1A, IAS-1, and JIFF13.