论文标题
拓扑金属状态的浮雕工程和边缘状态的杂交具有散装状态
Floquet engineering of topological metal states and hybridization of edge states with bulk states in dimerized two-leg ladders
论文作者
论文摘要
我们考虑不对称和对称二聚体两腿梯子，包括每个单位电池的四个不同的晶格点，并由圆形极化光照明。在不对称的二聚梯子箱中，梯级并非垂直于梯子的腿，而梯级则垂直于腿部的对称性。使用浮雕理论，我们获得了有效的哈密顿量来研究系统的拓扑特性。根据二聚化强度和驱动幅度，拓扑受保护的边缘状态不仅表现为传导和价带之间的间隙中的零能带，而且还表现为子带间隙内的有限能量弯曲带。后者可以渗透到散装状态中，并与散装状态杂交，揭示了在非对称阶梯案例中具有离域边缘状态的杂交浮雕拓扑金属相。但是，在对称梯子中，有限能源边缘状态虽然剩余的局部化可以与表现出浮雕拓扑金属相的扩展散装状态共存。
We consider asymmetric and symmetric dimerized two-leg ladders, comprising of four different lattice points per unit cell, illuminated by circularly polarized light. In the asymmetric dimerized ladder case, rungs are not perpendicular to the ladder's legs whereas the rungs are perpendicular to the legs for the symmetric one. Using the Floquet theory, we obtain an effective Hamiltonian to study topological properties of the systems. Depending on the dimerization strength and driving amplitude, it is shown that topologically protected edge states manifest themselves not only as a zero-energy band within the gap between conduction and valence band but also as finite-energy curved bands inside the gap of subbands. The latter one can penetrate into bulk states and hybridize with the bulk states revealing hybridized Floquet topological metal phase with delocalized edge states in the asymmetric ladder case. However, in the symmetric ladder, the finite-energy edge states while remaining localized can coexist with the extended bulk states manifesting Floquet topological metal phase.
