Intrinsic localized spin-wave resonances in ferromagnetic chains with nearest- and next-nearest-neighbor exchange interactions

We demonstrate analytically and numerically that the simplest isotropic ferromagnetic one-dimensional system to show intrinsic localized spin-wave resonances requires only isotropic exchange interactions between 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 strength of the next-nearest-neighbor--to--nearest-neighbor exchange interactions. In the small amplitude limit translating localized spin-wave resonances behave like solitons but for larger amplitudes they are scattered by the discreteness of the lattice and decay by radiating plane spin-wave modes.