Ferromagnetic Heisenberg model with the Dzyaloshinskii-Moriya interaction

Abstract

The spin-1/2 Heisenberg model is formulated in terms of a mean-field approximation (MFA) by using the matrix forms of spin operators ${\hat{S}}_x,{\hat{S}}_y$ and ${\hat{S}}_z$ in three-dimensions. The considered Hamiltonian consists of bilinear exchange interaction parameters $(J_x,J_y,J_z)$, Dzyaloshinskii-Moriya interactions $({\Delta }_x,{\Delta }_y,{\Delta }_z)$ and external magnetic field components $(H_x,H_y,H_z)$. The magnetization and its components are obtained in the MFA with the general anisotropic case with $J_x\ne J_y\ne J_z$ for various values of coordination numbers $q$. Then, the thermal variations of magnetizations are investigated in detail to obtain the phase diagrams of the model for the isotropic case with $J_x=J_y=J_z>0$. It is found that the model exhibits ferromagnetic, paramagnetic, random phase regions and an extra ferromagnetic phase at which the components of magnetizations present branching.

9 pages, 3 figures

References in corpus (4)

• Ising order in a magnetized Heisenberg chain subject to a uniform Dzyaloshinskii-Moriya interaction
• Spontaneous order in the highly frustrated spin-1/2 Ising-Heisenberg model on the triangulated Kagome lattice due to the Dzyaloshinskii-Moriya anisotropy
• Magnetic phase diagram of a spin-1/2 XXZ chain with modulated Dzyaloshinskii-Moriya interaction
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