Microwave spectroscopy of the low-temperature skyrmion state in Cu2OSeO3

Abstract

In the cubic chiral magnet Cu2OSeO3 a low-temperature skyrmion state (LTS) and a concomitant tilted conical state are observed for magnetic fields parallel to <100>. In this work, we report on the dynamic resonances of these novel magnetic states. After promoting the nucleation of the LTS by means of field cycling, we apply broadband microwave spectroscopy in two experimental geometries that provide either predominantly in-plane or out-of-plane excitation. By comparing the results to linear spin-wave theory, we clearly identify resonant modes associated with the tilted conical state, the gyrational and breathing modes associated with the LTS, as well as the hybridization of the breathing mode with a dark octupole gyration mode mediated by the magnetocrystalline anisotropies. Most intriguingly, our findings suggest that under decreasing fields the hexagonal skyrmion lattice becomes unstable with respect to an oblique deformation, reflected in the formation of elongated skyrmions.

References in corpus (10)

• A new class of chiral materials hosting magnetic skyrmions beyond room temperature
• Long wavelength helimagnetic order and skyrmion lattice phase in Cu2OSeO3
• Formation and rotation of skyrmion crystal in the chiral-lattice insulator Cu2OSeO3
• Observation of two independent skyrmion phases in a chiral magnetic material
• Symmetry breaking, slow relaxation dynamics, and topological defects at the field-induced helix reorientation in MnSi
• Current-induced viscoelastic topological unwinding of metastable skyrmion strings
• Low spin wave damping in the insulating chiral magnet Cu${}_2$OSeO${}_3$
• Thermodynamic evidence of a second skyrmion lattice phase and tilted conical phase in Cu${}_2$0SeO${}_3$
• Weak crystallization of fluctuating skyrmion textures in MnSi
• Observation of Coherent Helimagnons and Gilbert damping in an Itinerant Magnet

Cited by in corpus (23)

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• Tunable Cooperativity in Coupled Spin--Cavity Systems
• Chiral standing spin waves in skyrmion lattice
• Direct observation of the exchange anisotropy in the helimagnetic insulator Cu${}_2$OSeO${}_3$
• Confined dipole and exchange spin waves in a bulk chiral magnet with Dzyaloshinskii-Moriya interaction
• Experimental Evidence of a change of Exchange Anisotropy Sign with Temperature in Zn-Substituted Cu2OSeO3
• Optically excited spin dynamics of thermally metastable skyrmions in Fe${}_{0.75}$Co${}_{0.25}$Si
• Chiral surface spin textures in Cu${}_2$OSeO${}_3$ unveiled by soft x-ray scattering in specular reflection geometry
• Site-specific electronic and magnetic excitations of the skyrmion material Cu${}_2$OSeO${}_3$
• Dynamical susceptibility of Skyrmion crystal
• Skyrmion Crystal in a Microwave Field
• Short-wave magnons with multipole spin precession detected in the topological bands of a skyrmion lattice
• Growth and helicity of non-centrosymmetric Cu${}_2$OSeO${}_3$ crystals
• Hybrid magnetization dynamics in ${\text{Cu}}_{\text{2}}{\text{OSeO}}_{\text{3}}$/$\mathrm{NiFe}$ heterostructures
• Observation of distorted tilted conical phase at the surface of a bulk chiral magnet with resonant elastic x-ray scattering
• Cu2OSeO3 Turns Trigonal with Structural Transformation and Implications for Skyrmions
• Topological transition in spectrum of skyrmion crystal with uniaxial anisotropy
• Strong Coupling between Propagating Magnons and High-order Gyrotropic Skyrmion Modes
• Helical spin dynamics in Cu${}_2$OSeO${}_3$ as measured with small-angle neutron scattering