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PGI-1 Talk: Dr. Levente Rozsa

Magnetic structure of monatomic Fe chains on Re(0001): Emergence of chiral multispin interactions

26 Sep 2019 11:30
PGI lecture hall

University of Hamburg


Magnetic nanostructures on heavy-element superconducting surfaces are in the focus of recent research efforts, particularly because of the formation of noncollinear spin configurations, Yu-Shiba-Rusinov states, and Majorana bound states. The signatures of these phenomena have been recently studied in atomically fabricated Fe chains on the Re(0001) surface via scanning tunneling microscopy and spectroscopy measurements. Here we investigate the magnetic ground state and interactions in this system based on the screened Korringa-Kohn-Rostoker method, using different approaches.

In the first method, the magnetic degrees of freedom are mapped to a classical atomistic model Hamiltonian containing two-spin exchange interaction tensors by using the method of infinitesimal rotations around the collinear configuration, and the magnetic ground state is found via spin dynamics simulations. In the second method, the energy of the magnetic configuration is minimized within the self-consistent electronic structure calculations. The two calculations agree in predicting a spin spiral ground state for the 15-atom-long Fe chain on Re(0001), but the chirality of the spiral is found to differ between the approaches. This discrepancy is resolved by taking into account four-spin chiral interactions in an extended spin model.


Dr. Manuel dos Santos Dias
Phone: +49 2461 61-5956
Fax: +49 2461 61-2850
email: m.dos.santos.dias@fz-juelich.de