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arXiv · 2605.24430

Superconfined Antiferromagnons on the Two-Dimensional Penrose Lattice

Takashi Inoue·Shoji Yamamoto
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Abstract

We find novel confined states in the spin-$S$ nearest-neighbor antiferromagnetic Heisenberg model on the two-dimensional Penrose lattice. Linear spin waves have massively degenerate eigenstates strictly confined to tricoordinated sites. They contrast with the well-known itinerant analogs in the tight-binding model, where electrons are confined but extended to both tricoordinated and pentacoordinated sites. It is the site potentials in the spin-wave Hamiltonian, originating from Coulomb interactions between electrons, that confine spin waves to minimally coordinated sites only. Confined states in the tight-binding Hamiltonian consist of six types of building blocks, whereas those in the spin-wave Hamiltonian consist of only four of them. Confined spin waves are robust against $1/S$ corrections. Emergent $O(S^{0})$ interactions further confine -- superconfine -- spin waves into two separate groups within tricoordinated sites.

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Takashi Inoue, Shoji Yamamoto. 2026-05-23. Superconfined Antiferromagnons on the Two-Dimensional Penrose Lattice. https://doi.org/10.3390/cryst16060370

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