Driving a two-dimensional Mott insulator with circularly polarized light breaks time-reversal and inversion symmetry, which induces an optically-tunable synthetic scalar spin chirality interaction in the effective low-energy spin Hamiltonian. Here, we show that this mechanism can stabilize topological magnon excitations in honeycomb ferromagnets and in optical lattices. We find that the irradiated quantum magnet is described by a Haldane model for magnons that hosts topologically-protected edge modes. We study the evolution of the magnon spectrum in the Floquet regime and via time propagation of the magnon Hamiltonian for a slowly varying pulse envelope. Compared to similar but conceptually distinct driving schemes based on the Aharanov-Casher effect, the dimensionless light-matter coupling parameter $\lambda = eEa/\hbar\omega$ at fixed electric field strength is enhanced by a factor $\sim 10^5$. This increase of the coupling parameter allows to induce a topological gap of the order of $\Delta \approx 2$ meV with realistic laser pulses, bringing an experimental realization of light-induced topological magnon edge states within reach.

中文翻译：

---

二维范德华磁体中的光诱导拓扑磁振子

用圆偏振光驱动二维Mott绝缘子会破坏时间反转和反演对称性，从而在有效的低能量自旋哈密顿量中引起光学可调的合成标量自旋手性相互作用。在这里，我们证明了这种机制可以稳定蜂窝状铁磁体和光学晶格中的拓扑磁振子激发。我们发现，辐照的量子磁体是由Haldane模型描述的，其中包含了受拓扑保护的边缘模式的磁振子。我们研究了磁悬浮频谱在Floquet体制下的发展，并通过了一个缓慢变化的脉冲包络的磁悬浮哈密顿量的时间传播。与基于Aharanov-Casher效应的类似但概念上截然不同的驾驶方案相比，在固定电场强度下，无量纲的光-质耦合参数$ \ lambda = eEa / \ hbar \ omega $会增加$ \ sim 10 ^ 5 $。耦合参数的这种增加允许在实际的激光脉冲下感应出大约1到2 meV的拓扑间隙，从而在实验范围内实现了光诱导的拓扑磁振子边缘态的实验实现。