Electron paramagnetic resonance linewidth in a two-dimensional heisenberg antiferromagnet (S = 1/2) with skyrmeons

Abstract

Electron magnetic relaxation was studied in a two-dimensional Heisenberg antiferromagnet (S = 1/2) with skyrmeons. The electron paramagnetic resonance (EPR) linewidth (Γ⊥) was calculated at temperatures T ≤ J (J is the nearest-neighbor interaction constant). The magnitude of Γ⊥ caused by the Dzyaloshinskii-Moriya interaction is shown to grow as r0/a with decreasing temperature, whereas the anisotropic symmetric interaction leads to the (r0/a)3 dependence, where r0 is the average size of a skyrmeon and a is the lattice parameter. The results obtained agree qualitatively with calculations performed on the basis of a renormalization-group (RG) analysis of the nonlinear σ model at T ≪ J. © 2000 MAIK "Nauka/Interperiodica".