SurfaceScience21 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 25: Poster Session II: Surface magnetism II

O 25.2: Poster

Montag, 1. März 2021, 13:30–15:30, P

Domain Walls in the Row-Wise Antiferromagnet Mn/Re(0001) — •Martin Grünebohm, Jonas Spethmann, Roland Wiesendanger, Kirsten von Bergmannv, and André Kubetzka — Department of Physics, University of Hamburg, 20355 Hamburg, Germany

Typical domain walls (DWs) in antiferromgnetic (AFM) systems can be described by a coherent rotation, which allows a mapping onto ferromagnetic DWs. Experiments show, that in fcc-stacked monolayers of manganese on Re(0001), competing nearest and next-nearest neighbor Heisenberg exchange in combination with higher order interactions lead to a row-wise antiferromagnetic state (or 1Q state) [1]. We find that DWs, that separate the rotational domains, cannot be described by a coherent spin rotation. Instead, the low symmetry of the row-wise AFM state facilitates a new type of DW, which connects rotational domains by an opposite rotation of adjacent spin pairs across the wall. Interestingly, the non-collinear spin texture in the center of the DW has an angle of 90^∘ between neighboring spins, characteristic of a so-called 2Q state. We propose an analytical description and test it using spin dynamics simulations based on DFT calculations in comparison to spin-polarized STM measurements [2].

[1] J. Spethmann et al., Phys. Rev. Lett. 124, 227203 (2020).

[2] J. Spethmann et al., arXiv:2011.05678 (2020).