Dresden 2026 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 33: Altermagnets IV

MA 33.1: Vortrag

Mittwoch, 11. März 2026, 15:00–15:15, HSZ/0002

Magnon transport and surface effects in an altermagnetic toy model — •Moumita Kundu¹, Rabea Schmidhuber², Marian Duelli¹, and Ulrich Nowak¹ — ¹Fachbereich Physik, Universität Konstanz, Konstanz, Germany — ²Ludwig-Maximilians-Universität München, Geschwister-Scholl-Platz 1, 80539 München, Germany

Altermagnets are a recently discovered class of magnetic materials that show non-relativistic spin-splitting of the magnon bands and on exposure to a thermal gradient can carry a net magnetization unlike conventional antiferromagnets. Here, we present a simplistic toy model of an altermagnet having asymmetric exchange interactions in a checkered antiferromagnetic lattice. Using atomistic spin dynamic simulations based on the stochastic-LLG equation we obtain the spin dynamics. The altermagnetic phase is confirmed from magnon dispersions under a steady thermal excitation revealing chiral spin splitting as expected along one of the high-symmetry directions [ 110 ] and directions orthogonal to it. Surface effects are a direct outcome from these calculations, showing an orientation dependent surface magnetization detected for each cut of the sample. The spin Seebeck and spin Nernst effects are investigated both showing unique orientation dependent net magnetization and magnon accumulations following the lattice symmetries. Owing to the nondegenerate magnons branches, the group velocities of the corresponding magnons vary leading to distinct propagation lengths of the RH- and LH- modes predominant along different directions. The robustness to external magnetic fields is explored revealing preferential band liftings with an additional gap at the Γ point.

Keywords: Magnon transport; Spin Seebeck effect; Spin Nernst effect; Surface effects; Zeeman field