Non-Collinear and Non-Coplanar Magnetic Orders in 1/1 Periodic Approximant to the Icosahedral Quasicrystal

TL;DR

This study theoretically investigates the ground-state magnetic structures of rare-earth 1/1 approximants to icosahedral quasicrystals, revealing eight stable noncollinear and noncoplanar magnetic orders with topological properties.

Contribution

The paper introduces a comprehensive effective model and numerical analysis that identify multiple complex magnetic phases in rare-earth 1/1 approximants, linking them to experimental observations.

Findings

Eight magnetic structures stabilized with distinct space groups.

Degeneracy of ground states suggests multiple domain formations.

Topological properties of magnetic states are characterized.

Abstract

Ground-state properties of rare-earth based 1/1 periodic approximants of icosahedral quasicrystal are clarified theoretically on the basis of an effective model for magnetism taking into account uniaxial anisotropy arising from crystalline electric field. By performing numerically-exact calculation on the 1/1 approximant crystal with a lattice constant $a$=14.725 \AA, we have determined the ground-state phase diagram for ferromagnetic interactions. The result shows that eight kinds of noncollinear and noncoplanar magnetic structures are stabilized, whose magnetic space groups are identified as $I_{\rm P}m'\bar{3}'$, $C2'/m'$ and $R\bar{3}$. We have clarified the degeneracy of each ground state, which is expected to be reflected in the numbers of the domains. By analyzing each state, the magnetic as well as topological properties are revealed. Our results are shown to explain the measured magnetic structures in the 1/1 approximants and the effective model is discussed to be useful for understanding the magnetic structures and their topological properties in broad range of rare-earth based 1/1 approximants.