Spin-wave approach to the two-magnon Raman scattering in aJ1x−J1y−J2−Jcantiferromagnetic Heisenberg model

Abstract

We study the two-magnon nonresonant Raman scattering in the $(\ensuremath{\pi},\ensuremath{\pi})$ and $(\ensuremath{\pi},0)$ in-plane ordered antiferromagnetic phases of a spin-$S{J}_{1x}\text{\ensuremath{-}}{J}_{1y}\text{\ensuremath{-}}{J}_{2}\text{\ensuremath{-}}{J}_{c}$ Heisenberg model on the tetragonal lattice within the framework of the spin-wave theory. We show that magnon-magnon interactions may significantly change the shape of spectra even in large-$S$ cases. We discuss the effects of various tuning factors to the two-magnon Raman spectra. We find that both the magnetic frustration ${J}_{2}/{J}_{1}$ and the interlayer exchange coupling ${J}_{c}$ may significantly affect the spectra in both the ${B}_{1g}$ and the ${A}_{1g}^{\ensuremath{'}}$ channels in the $(\ensuremath{\pi},\ensuremath{\pi})$ N\'eel ordered phase. Moreover, we find a splitting of the two-magnon peak in the $(\ensuremath{\pi},0)$ collinear antiferromagnetic phase. We further discuss the implications of our results to the ${\mathrm{BaMnBi}}_{2}$ and iron pnictide systems.