Nucleation, instability, and discontinuous phase transitions in monoaxial helimagnets with oblique fields

Abstract

The phase diagram of the monoaxial chiral helimagnet as a function of temperature (T ) and magnetic field with components perpendicular (H x ) and parallel (H z ) to the chiral axis is theoretically studied via the variational mean field approach in the continuum limit. A phase transition surface in the three dimensional thermodynamic space separates a chiral spatially modulated phase from a homogeneous forced ferromagnetic phase. The phase boundary is divided into three parts: two surfaces of second order transitions of instability and nucleation type, in De Gennes terminology, are separated by a surface of first order transitions. Two lines of tricritical points separate the first order surface from the second order surfaces. The divergence of the period of the modulated state on the nucleation transition surface has the logarithmic behavior typical of a chiral soliton lattice. The specific heat diverges on the nucleation surface as a power law with logarithmic corrections, while it shows a finite discontinuity on the other two surfaces. The soliton density curves are described by a universal function of H x if the values of T and H z determine a transition point lying on the nucleation surface; otherwise, they are not universal.

Phase diagram refined, with a new tricritical point located; 9 pages, 8 figures; version shortened, published in Phys. Rev. B

References in corpus (5)

• Finite-Temperature Properties of Three-Dimensional Classical Chiral Helimagnets
• Understanding the H-T phase diagram of the mono-axial helimagnet
• Spin Structure of the Anisotropic Helimagnet Cr${}_{1/3}$NbS${}_2$ in a Magnetic Field
• Incommensurate--commensurate transitions in the mono-axial chiral helimagnet driven by the magnetic field
• Phase transitions and ordering structures of a model of chiral helimagnet in three dimensions

Cited by in corpus (11)

• Crossover of skyrmion and helical modulations in noncentrosymmetric ferromagnets
• Magnetic field dependence of the nonlinear magnetic response and tricritical point in the monoaxial chiral helimagnet Cr${}_{1/3}$NbS${}_2$
• Chiral solitons in monoaxial chiral magnets in tilted magnetic field
• Stability of skyrmion textures and the role of thermal fluctuations in cubic helimagnets: a new intermediate phase at low temperature
• Thermal fluctuations in the conical state of monoaxial helimagnets
• Instabilities in monoaxial chiral magnets under a tilted magnetic field
• AC magnetic response of highly nonlinear soliton lattice in a monoaxial chiral helimagnet
• Scattering of spin waves by a Bloch domain wall: effect of the dipolar interaction
• Response of the chiral soliton lattice to spin polarized currents
• The continuum of metastable conical states of monoaxial chiral helimagnets
• Spin-current diode with a monoaxial chiral magnet