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 $|N_{\mathrm{sk}}|=1$ 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 $|N_{\mathrm{sk}}|=1$ to another skyrmion lattice with $|N_{\mathrm{sk}}|=2$ or to a nontopological magnetic order with $|N_{\mathrm{sk}}|=0$ 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 light of time-evolution equations based on an effective model derived using perturbation expansions.

中文翻译：

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微波驱动磁体中磁拓扑的动态切换

我们通过在三角形晶格上采用 Kondo-lattice 模型，从理论上证明了中心对称流动磁铁中磁拓扑的微波诱导动态切换，已知三角形晶格表现出两种类型的具有不同磁拓扑电荷的斯格明子晶格 $|N_{\mathrm{斯克}}|=1$ 和 2. 我们的数值模拟表明，具有圆极化微波场的共振模式的强烈激发可以切换磁拓扑，即从具有 $|N_{\mathrm{斯克}}|=1$ 到另一个斯格明子格子 $|N_{\mathrm{斯克}}|=2$ 或到非拓扑磁序 $|N_{\mathrm{斯克}}|=0$取决于微波频率。这种磁拓扑切换表现出各种不同的行为，即确定性不可逆切换、概率不可逆切换和取决于微波频率和外部磁场强度的时间随机波动，其变化归因于不同的能量景观动态制度。还根据基于使用扰动扩展导出的有效模型的时间演化方程讨论了获得的结果。