Stability of skyrmion textures and the role of thermal fluctuations in cubic helimagnets: a new intermediate phase at low temperature

Abstract

The stability of the four known stationary points of the cubic helimagnet energy functional: the ferromagnetic state, the conical helix, the conical helicoid, and the skyrmion lattice, is studied by solving the corresponding spectral problem. The only stable points are the ferromagnetic state at high magnetic field and the conical helix at low field, and there is no metastable state. Thermal fluctuations around the stationary point, included to quadratic order in the saddle point expansion, destabilize the conical helix in a region where the ferromagnetic state is unstable. Thus, a new intermediate phase appears which, in a region of the phase diagram, is a skyrmion lattice stabilized by thermal fluctuations. The skyrmion lattice lost the stability by lowering temperature, and a new intermediate phase of unknown type, presumably with three dimensional modulations, appears in the lower temperature region.

9 pages, 7 figures

References in corpus (7)

• Magnon-skyrmion scattering in chiral magnets
• Fluctuation-induced first-order phase transition in Dzyaloshinskii-Moriya helimagnets
• Three-dimensional skyrmion states in thin films of cubic helimagnets
• Three-dimensional chiral skyrmions with attractive interparticle interactions
• Understanding the H-T phase diagram of the mono-axial helimagnet
• Incommensurate--commensurate transitions in the mono-axial chiral helimagnet driven by the magnetic field
• Nucleation, instability, and discontinuous phase transitions in monoaxial helimagnets with oblique fields

Cited by in corpus (8)

• Colloquium: Quantum Properties and Functionalities of Magnetic Skyrmions
• Widely-sweeping magnetic field-temperature phase diagrams for skyrmion-hosting centrosymmetric tetragonal magnets
• Thermal fluctuations in the conical state of monoaxial helimagnets
• Stability of the skyrmion lattice near the critical temperature in cubic helimagnets
• Robust metastable skyrmions with tunable size in the chiral magnet FePtMo${}_3$N
• Scattering of spin waves by a Bloch domain wall: effect of the dipolar interaction
• An improved discretization of Schrodinger-like radial equations
• The continuum of metastable conical states of monoaxial chiral helimagnets