# Spin excitation spectra in helimagnetic states: Proper-screw, cycloid, vortex-crystal, and hedgehog lattices

@article{Kato2021SpinES, title={Spin excitation spectra in helimagnetic states: Proper-screw, cycloid, vortex-crystal, and hedgehog lattices}, author={Yasuyuki Kato and Satoru Hayami and Yukitoshi Motome}, journal={Physical Review B}, year={2021} }

We investigate the spin excitation spectra in chiral and polar magnets by the linear spin-wave theory for an effective spin model with symmetric and antisymmetric long-range interactions. In one dimension, we obtain the analytic form of the dynamical spin structure factor for proper-screw and cycloidal helical spin states with uniform twists, which shows a gapless mode with strong intensity at the helical wave number. When introducing spin anisotropy in the symmetric interactions, we…

## Figures and Tables from this paper

## One Citation

Phase degree of freedom and topology in multiple-$Q$ spin textures

- Physics
- 2022

A periodic array of topological spin textures, such as skyrmions and hedgehogs, is called the multiple-Q spin texture, as it is represented by a superposition of multiple spin density waves.…

## References

SHOWING 1-10 OF 99 REFERENCES

Symmetry, Structure, and Dynamics of Monoaxial Chiral Magnets

- Physics
- 2016

Nontrivial spin orders with magnetic chirality emerge in a particular class of magnetic materials with structural chirality, which are frequently referred to as chiral magnets. Various interesting…

Multiple-
Q
magnetic orders in Rashba-Dresselhaus metals

- PhysicsPhysical Review B
- 2018

We study magnetic textures realized in noncentrosymmetric Kondo lattice models, in which localized magnetic moments weakly interact with itinerant electrons subject to Rashba and Dresselhaus…

Effect of magnetic anisotropy on skyrmions with a high topological number in itinerant magnets

- PhysicsPhysical Review B
- 2019

We report our numerical results for the effect of magnetic anisotropy on a Skyrmion crystal with a high topological number of two, which was recently discovered in an itinerant electron model [R.…

Néel- and Bloch-Type Magnetic Vortices in Rashba Metals.

- Physics, MedicinePhysical review letters
- 2018

This work derives an effective spin model with generalized Ruderman-Kittel-Kasuya-Yosida interactions including the anisotropic and antisymmetric exchange interactions and finds that a vortex crystal of Néel type is stabilized even in the absence of a magnetic field.

Spin-resolved inelastic electron scattering by spin waves in noncollinear magnets

- Physics
- 2018

Topological non-collinear magnetic phases of matter are at the heart of many proposals for future information nanotechnology, with novel device concepts based on ultra-thin films and nanowires. Their…

Skyrmions in chiral magnets with Rashba and Dresselhaus spin-orbit coupling

- Physics
- 2016

Skyrmions are topological spin textures of interest for fundamental science and applications. Previous theoretical studies have focused on systems with broken bulk inversion symmetry, where skyrmions…

Topological spin crystals by itinerant frustration

- Physics, MedicineJournal of physics. Condensed matter : an Institute of Physics journal
- 2021

Focusing on the interplay between charge and spin degrees of freedom in itinerant electron systems, it is shown that itinerant frustration, which is the competition among electron-mediated interactions, plays a central role in stabilizing a variety of topological spin crystals including a skyrmion crystal with unconventional high skyrnion number, meron crystals, and hedgehog crystals.

Multiply periodic states and isolated skyrmions in an anisotropic frustrated magnet

- Physics, MedicineNature communications
- 2015

The phase diagram of an anisotropic frustrated magnet which contains five different multiply periodic states including the skyrmion crystal is studied to show that skyrMion materials with rich physical properties can be found among frustrated magnets.

Direct Observation of the Statics and Dynamics of Emergent Magnetic Monopoles in a Chiral Magnet.

- Medicine, PhysicsPhysical review letters
- 2020

This work observes a dramatic change in the Hall effect upon the transformation of a spin hedgehog crystal in a chiral magnet MnGe through combined measurements of magnetotransport and small-angle neutron scattering (SANS).

Real-space observation of a two-dimensional skyrmion crystal

- Chemistry, MedicineNature
- 2010

Real-space imaging of a two-dimensional skyrmion lattice in a thin film of Fe0.5Co 0.5Si using Lorentz transmission electron microscopy reveals a controlled nanometre-scale spin topology, which may be useful in observing unconventional magneto-transport effects.