  We theoretically demonstrate microwave-induced dynamical switching of
magnetic topology in centrosymmetric itinerant magnets by taking the
Kondo-lattice model on a triangular lattice, which is known to exhibit two
types of skyrmion lattices with different magnetic topological charges of |Nsk|
= 1 and 2. Our numerical simulations reveal that intense excitation of a
resonance mode with circularly polarized microwave field can switch the
magnetic topology, i.e., from the skyrmion lattice with |Nsk| = 1 to another
skyrmion lattice with |Nsk| = 2 or to a nontopological magnetic order with
|Nsk| = 0 depending on the microwave frequency. This magnetic-topology
switching shows various distinct behaviors, that is, deterministic irreversible
switching, probabilistic irreversible switching, and temporally random
fluctuation depending on the microwave frequency and the strength of the
external magnetic field, the variety of which is attributable to different
energy landscapes in the dynamical regime. The obtained results are also
discussed in the light of time-evolution equations based on an effective model
derived using perturbation expansions.
