Multifractal Magnons Around Localized Defects
Abstract
Multifractal wavefunctions fluctuate over a hierarchy of spatial scales, remaining spatially extended while exhibiting strongly nonuniform structure. We show that magnons in otherwise crystalline two-dimensional magnets can exhibit such behavior on mesoscopic scales, without disorder or quasiperiodicity. A localized defect can mix discrete groups of nearly degenerate magnon states in a finite sample, generating multiscale interference patterns and multifractal wavefunctions. We demonstrate this mechanism for both a simple spin defect and topological magnetic skyrmions. Large-scale spin-wave calculations for skyrmions in chiral and frustrated magnets reveal clear multifractal diagnostics over the full accessible range of system sizes of above-gap modes. Crucially, skyrmions make these states experimentally observable by hybridizing them with magnetically active internal deformation modes, which gives a subset of the multifractal states a nonzero magnetic dipole moment. These states can therefore be excited by uniform ac fields and remain distinguishable at realistic frequency resolution, providing a direct route to observing mesoscopic magnon multifractality.
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BibTeX
@misc{hullahalli2026multifractal,
title = {{Multifractal Magnons Around Localized Defects}},
author = {Adarsh Hullahalli and Yusuf Khand and Christos Panagopoulos and Christina Psaroudaki},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.32457},
eprint = {2610.32457},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.32457},
}
RIS
TY - UNPB
TI - Multifractal Magnons Around Localized Defects
AU - Adarsh Hullahalli
AU - Yusuf Khand
AU - Christos Panagopoulos
AU - Christina Psaroudaki
PY - 2026
DA - 2026/10/23
PB - arXiv
DO - 10.48550/arxiv.2610.32457
UR - https://arxiv.org/abs/2610.32457
AB - Multifractal wavefunctions fluctuate over a hierarchy of spatial scales, remaining spatially extended while exhibiting strongly nonuniform structure. We show that magnons in otherwise crystalline two-dimensional magnets can exhibit such behavior on mesoscopic scales, without disorder or quasiperiodicity. A localized defect can mix discrete groups of nearly degenerate magnon states in a finite sample, generating multiscale interference patterns and multifractal wavefunctions. We demonstrate this mechanism for both a simple spin defect and topological magnetic skyrmions. Large-scale spin-wave calculations for skyrmions in chiral and frustrated magnets reveal clear multifractal diagnostics over the full accessible range of system sizes of above-gap modes. Crucially, skyrmions make these states experimentally observable by hybridizing them with magnetically active internal deformation modes, which gives a subset of the multifractal states a nonzero magnetic dipole moment. These states can therefore be excited by uniform ac fields and remain distinguishable at realistic frequency resolution, providing a direct route to observing mesoscopic magnon multifractality.
ER -