Berlin 2018 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 52: Poster II

MA 52.16: Poster

Donnerstag, 15. März 2018, 15:00–18:00, Poster C

Towards a complete first principles parameterisation of magnetic materials as input for atomistic spin dynamics simulations — •Mario Galante, Matthew O. A. Ellis, Alessandro Lunghi, and Stefano Sanvito — School of Physics, Trinity College Dublin, Ireland

Atomistic spin dynamics has proven to be an invaluable tool to investigate the behaviour of magnetic nanomaterials. It is based on a Heisenberg spin model, where the spin magnetic moment is localised to each atomic site and obeys the Landau-Lishfitz-Gilbert-like (LLG) equations of motion. The solution of such equations requires the knowledge of some material-dependent microscopic properties such as the inter-atomic exchange, the magnetic anisotropy and the Gilbert damping. In nanoscale systems strain and interfaces can greatly alter the electronic structure, hence input parameters from ab-initio are desirable since they can provide system-tailored and atom resolved information. Furthermore, methods based on density functional theory including spin orbit interactions are suitable to perform high-throughput calculations of such quantities. In this work we analyse the suitability of the recipes provided in Refs. [1,2] to calculate the magnetic anisotropy and the inter-atomic exchange parameters respectively, using our own implementation based on the SIESTA code [3]. We then discuss a new parameter-free method to estimate the Gilbert damping based on a finite difference solution of the Liouville equation. [1] Schmitt et al, J. Chem. Phys. 134, 194113 (2011) [2] Korotin et al, PRB 91, 224405 (2014) [3] Soler et al, J. Phys.: Cond. Mat. 14, 2745 (2002)