INTRINSIC LOCALIZED SPIN-WAVE RESONANCES IN FERROMAGNETIC CHAINS WITHNEAREST-NEIGHBOR AND NEXT-NEAREST-NEIGHBOR EXCHANGE INTERACTIONS

We demonstrate analytically and numerically that the simplest isotropi c ferromagnetic one-dimensional system to show intrinsic localized spi n-wave resonances requires only isotropic exchange interactions betwee n first and second neighbors. Our numerical simulations indicate that the lifetime of these intrinsic localized spin-wave resonances depends on the mode parity, the maximum spin deviation, and the relative stre ngth of the next-nearest-neighbor-to-nearest-neighbor exchange interac tions. In the small amplitude limit translating localized spin-wave re sonances behave like solitons but for larger amplitudes they are scatt ered by the discreteness of the lattice and decay by radiating plane s pin-wave modes.