# Effect of disorder on the collective excitations of the chiral spin soliton lattice

## TL;DR

This study investigates how magnetic disorder influences the spin excitation spectra of the chiral spin soliton lattice in CrNb3S6, revealing that disorder affects resonance modes and can be controlled via external magnetic fields.

## Contribution

It demonstrates the impact of magnetic disorder on collective spin excitations in a noncollinear spin system and shows how external fields can suppress disorder effects.

## Key findings

- Resonance modes depend on magnetic disorder levels.
- Disorder can be suppressed by sweeping the external magnetic field.
- Macroscopic coherence of the CSL is observable through collective dynamics.

## Abstract

We assess the impact of magnetic disorder on the spin excitation spectra of the chiral helimagnetic crystal $\mathrm{CrNb_3S_6}$ using microwave resonance spectroscopy. The chiral spin soliton lattice phase (CSL), which is a prototype of a noncollinear spin system that forms periodically over a macroscopic length scale, exhibited three resonance modes over a wide frequency range. We found that the predominance of these modes depended on the degree of magnetic disorder and that disorder can be suppressed by sweeping the external field via an ideal helical state at 0~T. The macroscopic coherence of the CSL can be clearly observed through its collective dynamic behavior. Our study suggests that magnetic disorder can be used as a mechanism to control spin wave excitation in noncollinear spin systems.