The stability of the existence of the topological properties even in non-equilibrium condition such as irradiation of external time-periodic perturbation paves the way for designing and controlling the properties of materials. We study the change in the structure of the quasi-energy spectrum under the influence of the circularly polarized laser field with various intensities. The system is two-dimensional honeycomb nanoribbon of having zig-zag edges. Two cases where the onsite energies are present and absent are considered. We find that the topological phase transitions occur at some critical intensities of the laser field in both cases, which are recognized by the gap closing, the appearance of two crossing edge states, and sudden raise of the first Chern number from 0 to 1. The critical laser intensity is raised when either the frequency increases or the width of the ribbon decreases. Furthermore, band folding is observed in low-frequency domain in the quasi-energy spectrum and becomes more pronounced for the lower frequencies.

中文翻译：

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圆偏振激光场辐照蜂窝纳米带中絮状拓扑相的诱导

即使在诸如外部时间周期扰动的辐照等非平衡条件下，拓扑性质的存在稳定性也为设计和控制材料的性质铺平了道路。我们研究了在不同强度的圆偏振激光场的影响下准能谱结构的变化。该系统是具有锯齿形边缘的二维蜂窝状纳米带。考虑了现场能量存在和不存在的两种情况。我们发现，在这两种情况下，拓扑相变都发生在激光场的某些临界强度处，这可以通过间隙闭合、两个交叉边缘状态的出现以及第一个陈数从 0 突然上升到 1 来识别。当频率增加或条带宽度减小时，临界激光强度会增加。此外，在准能谱的低频域中观察到带折叠，并且在较低频率处变得更加明显。