Orbital ordering effect on magnetic resonance spectra in charge-ordered and frustrated manganites

A theoretical study of the interrelation of the crystal structure, charge, orbital, and magnetic subsystems in $R_{1-x}A_{x}$MnO$_{3}$ charge-ordered manganites has been carried out (where $R^{3+}$ is the rare earth ion, $A^{2+}$ is the alkaline earth metal ion, $x$ = 0.5, 2/3). The model of orbital-dependent exchange interactions and single-ion anisotropy is used. The presence of quasi-low-dimensional magnetic structures is exhibited. The spin waves spectra and antiferromagnetic resonance spectra are calculated.