Quasicrystalline chiral soliton lattices in a Fibonacci helimagnet

TL;DR

This paper explores the complex magnetic structures in a Fibonacci helimagnet, revealing diverse quasicrystalline chiral soliton lattices and transitions influenced by external magnetic fields and quasiperiodic interactions.

Contribution

It introduces a detailed analysis of magnetic textures in a Fibonacci chain with Dzyaloshinskii-Moriya interactions, highlighting the emergence of quasicrystalline soliton lattices and phase transitions.

Findings

Identification of various magnetic textures under different magnetic fields.

Discovery of a transition from helical to soliton lattice configurations.

Observation of a commensurate-incommensurate transition with discommensurations.

Abstract

We investigate the ground state magnetic configurations of a Fibonacci chain of classical spins with nearest-neighbor ferromagnetic and monoaxial Dzyaloshinskii-Moriya exchange interactions. Our analysis reveals a diverse array of magnetic textures induced by an external magnetic field perpendicular to the Dzyaloshinskii-Moriya vector. These textures exhibit a spectrum ranging from a quasi-fully polarized non-collinear state under high magnetic fields, capable of maintaining metastable chiral soliton topological defects, to a variety of quasicrystalline chiral soliton lattices below a critical field $H_c$. For a range of magnetic fields below $H_c$, the ground state spin textures result from the interplay between an effective quasiperiodic potential influencing the solitons and their repulsive interactions. At lower magnetic fields, the system experiences a commensurate-incommensurate transition, signified by the appearance of discommensurations in the quasicrystalline soliton lattice. In the absence of an external magnetic field, the ground state assumes a helical configuration with a quasiperiodic pitch angle.