Assessing different approaches to ab initio calculations of spin wave stiffness

0537711 - FZÚ 2021 RIV US eng J - Journal Article
Šipr, Ondřej - Mankovsky, S. - Ebert, H.
Assessing different approaches to ab initio calculations of spin wave stiffness.
Physical Review B. Roč. 101, č. 13 (2020), s. 1-10, č. článku 134409. ISSN 2469-9950. E-ISSN 2469-9969
R&D Projects: GA ČR(CZ) GA17-12925S
Institutional support: RVO:68378271
Keywords : exchange coupling * spin spiral * stiffness
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 4.036, year: 2020
Method of publishing: Limited access
https://doi.org/10.1103/PhysRevB.101.134409

We present results for the stiffness constant D of Fe, Ni, and permalloy Fe0.19Ni0.81 obtained by three different approaches: (i) by finding the quadratic term coefficient of the power expansion of the spin-wave energy dispersion, (ii) by a damped real-space summation of weighted exchange coupling constants, and (iii) by integrating the appropriate expression in reciprocal space. All approaches are implemented by means of the same Korringa-Kohn-Rostoker (KKR) Green’s function formalism. We demonstrate that if properly converged, all procedures yield comparable values, with uncertainties of 5–10% remaining. By a careful analysis of the influence of various technical parameters, we estimate the margin of errors for the stiffness constants evaluated by different approaches and suggest procedures to minimize the risk of getting incorrect results.
Permanent Link: http://hdl.handle.net/11104/0315567