论文标题
Floquet绝缘子中的矢量拓扑边缘孤子
Vector Topological Edge Solitons in Floquet Insulators
论文作者
论文摘要
我们在Floquet绝缘子中介绍了拓扑矢量边缘孤子,由两个蜂窝阵列组成的螺旋波导阵列在聚焦非线性光学介质中具有相反旋转方向的蜂窝阵列。触点的两个阵列的曲折边缘创建了两个具有不同拓扑结构的结构之间的锯齿形Zigzag界面。这种光子绝缘子的一个特征是,在线性极限中,它同时支持两个阵列之间界面处的两个受拓扑保护的手性边缘状态。在存在非线性的情况下,明亮或深色标量浮子边缘可以从线性拓扑边缘状态分叉。这样的孤子是单向的,并且由于非线性自我行动而沿界面以及界面沿两个方向局部,作为边缘状态。具有相等平均群体速度的两个边缘状态的存在使得存在稳定的拓扑矢量边缘孤子。在我们的情况下,这些是从拓扑浮雕边缘状态的不同分支的非线性耦合的明亮和深色孤子。在这里,我们提出了上述连续系统中标量和矢量小振幅浮雕孤子的新数学描述。重要的是,对于基于Floquet Edge Soliton的未来光子设备的设计,我们发现后者可以通过非线性Schrodinger方程来描述,用于通过在进化坐标中的一个旋转期间平均获得的模式信封。
We introduce topological vector edge solitons in a Floquet insulator, consisting of two honeycomb arrays of helical waveguides with opposite directions of rotation in a focusing nonlinear optical medium. Zigzag edges of two arrays placed in contact create a zigzag-zigzag interface between two structures with different topology. A characteristic feature of such a photonic insulator is that, in the linear limit, it simultaneously supports two topologically protected chiral edge states at the interface between the two arrays. In the presence of nonlinearity, either bright or dark scalar Floquet edge soliton can bifurcate from a linear topological edge state. Such solitons are unidirectional and are localized in both directions, along the interface due to nonlinear self-action, and across the interface as being an edge state. The presence of two edge states with equal averaged group velocities enables the existence of stable topological vector edge solitons. In our case, these are nonlinearly coupled bright and dark solitons bifurcating from different branches of the topological Floquet edge states. Here we put forward a new mathematical description of scalar and vector small-amplitude Floquet envelope solitons in the above-mentioned continuous system. Importantly for the design of future photonic devices based on Floquet edge solitons, we find that the latter can be described by nonlinear Schrodinger equations for the mode envelopes obtained by averaging over one rotation period in the evolution coordinate.