Ferromagnetic Heisenberg model with the Dzyaloshinskii-Moriya interaction


ALBAYRAK E.

CONDENSED MATTER PHYSICS, vol.25, no.3, 2022 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 25 Issue: 3
  • Publication Date: 2022
  • Doi Number: 10.5488/cmp.25.33701
  • Journal Name: CONDENSED MATTER PHYSICS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, INSPEC, Directory of Open Access Journals
  • Keywords: spin 1/2, ferromagnetic, Dzyaloshinskii-Moriya, XYZ model, magnetization, phase diagrams
  • Erciyes University Affiliated: Yes

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 (S) over cap (x), (S) over cap (y) and (S) over cap (z) in three-dimensions. The considered Hamiltonian consists of bilinear exchange interaction parameters (J(x), J(y), J(z)), Dzyaloshinskii-Moriya interactions (Lambda(x), Lambda(y), Lambda(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) +/- J(y) +/- J(z) for various values of coordination numbers... 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.