Spin texture induced by non-magnetic doping and spin dynamics in 2D triangular lattice antiferromagnet h-Y(Mn,Al)O3

TL;DR

This study demonstrates that nonmagnetic doping in a 2D triangular antiferromagnet induces unique spin textures, confirmed by neutron scattering and theoretical modeling, revealing impurity effects in noncollinear magnetic systems.

Contribution

First experimental confirmation of impurity-induced extended spin textures in a 2D triangular antiferromagnet using neutron scattering and theoretical analysis.

Findings

Detection of magnon damping with momentum dependence

Reproduction of INS data features by theoretical calculations

Identification of impurity-induced spin textures

Abstract

Novel effects induced by nonmagnetic impurities in frustrated magnets and quantum spin liquid represent a highly nontrivial and interesting problem. A theoretical proposal of extended modulated spin structures induced by doping of such magnets, distinct from the well-known skyrmions has attracted significant interest. Here, we demonstrate that nonmagnetic impurities can produce such extended spin structures in h-YMnO3, a triangular antiferromagnet with noncollinear magnetic order. Using inelastic neutron scattering (INS), we measured the full dynamical structure factor in Al-doped h-YMnO3 and confirmed the presence of magnon damping with a clear momentum dependence. Our theoretical calculations can reproduce the key features of the INS data, supporting the formation of the proposed spin textures. As such, our study provides the first experimental confirmation of the impurity-induced spin textures. It offers new insights and understanding of the impurity effects in a broad class of noncollinear magnetic systems.