ELFT HÍRADÓ

[Szeminárium koordinátor <szfi-seminar AT wigner.mta.hu>]

SZFI SzemináriumLászlóffy AndrásMTA Wigner FK SZFIMagnetic structure of Fe 
chains on Re(0001)2019. november 19. kedd, 10.00, KFKI Telephely, I. épület 
1. emeleti TanácsteremWe present first principles calculations for closed 
packed chains of 5, 10 and 15 Fe atoms on the top of Re(0001) surface. We use 
the Embedded Cluster Korringa-Kohn-Rostoker Green's function scheme to 
investigate the magnetic properties of the systems, as well as the 
Relativistic Torque method to generate tensorial interactions of a classical 
spin model. It turns out that the nearest-neigbor isotropic couplings are 
antiferromagnetic and the easy axis is in-plane and perpendicular to the 
chain direction. The 5 and 10-atom-long Fe chains somewhat deviate from a 
collinear state due to Dzyaloshinskii-Moriya (DM) interactions and two-site 
anisotropies. The 15-atom chain displays a spin-spiral ground state being 
close to an AFM state, with a modulation wavelength of 14 atom. Because of 
the out-of-plane hard axis the spins lie in-plane and the DM interactions 
determine the chirality of the spin spiral. Direct ab initio simulation of 
the ground state results in a similar magnetic structure, but with opposite 
chirality. Supported by suitable magnetic force theorem calculations, we 
propose that introducing four-spin chiral interactions in the spin-model is 
crucial to understand the chirality of the spin-spiral ground state of the 
chain. Minden érdeklődőt szívesen látunk! - Everyone is welcome to 
attend.Juhász Róbertszfi-seminar AT wigner.mta.hu