Magnon-Magnon and Exciton-Magnon Interaction Effects on Antiferromagnetic Spectra

Two-magnon absorption and Raman experiments create pairs of magnons in close proximity, and hence, the magnon-magnon interaction has an important effect on the spectral line shape. Green's-function methods have been used to calculate this effect and the results applied the example of cubic antiferromagnets like RbMn${\mathrm{F}}_3$. Similar techniques are used to find the effect of exciton-magnon interaction on the sidebands in RbMn${\mathrm{F}}_3$; corresponding experimental results are presented.