Microwave field driven dynamics of spin, chirality, and topology in skyrmion lattices

Skyrmions, with both topological and chiral degrees of freedom, hold significant promise for future information storage technologies. However, the dynamic behaviors of both chirality and topology remain unclear, and challenges persist in the annihilation and recovery of these topologically nontrivial magnetic structures. In this study, we report the dynamic behavior of the skyrmion lattice in a microwave field using micromagnetism simulation and statistical analysis. By analyzing the time correlation functions of spin, spin chirality, and topology, we find that the dynamical responses of the three quantities to the microwave field are not synchronized. Our dynamical analysis reveals that nonlinear effects persist in the system, regardless of whether the skyrmion is annihilated. We observe frequency multiplier modes for the spin, spin chirality, and topology across all excitation frequency ranges. Notably, in the frequency range where skyrmions are annihilated, the composite mode $n{f}_{0}\ifmmode\pm\else\textpm\fi{}{f}^{\ensuremath{'}}$ ($n$ is an integer) is more prominent for spin and spin chirality. Furthermore, the ferromagnetic state can be nearly fully restored to the skyrmion lattice if one adjusts external parameters such as the amplitude of the microwave field and the temperature. This work distinguishes chirality and topological fluctuations through dynamic statistical methods, providing a theoretical basis for the design of new spintronic devices based on chirality-topology coupling.