论文标题
定期驱动的高阶Weyl半法的铰链模式动力学
Hinge mode dynamics of periodically driven higher-order Weyl semimetals
论文作者
论文摘要
我们研究了二阶拓扑材料的铰链模式的频镜动力学，该材料是通过离散（平方脉冲）和连续（cesine）周期性驱动方案的中间驱动频率方案中的立方晶格上的紧密结合的Fermion Hamiltonian建模的。我们分析了该系统的浮标阶段，并表明其对准频谱在特殊驱动频率下的大型驱动振幅方案中几乎变得无处不在。远离这些频率，差异的准谱频谱支持弱分散的浮力铰链模式。这些铰链模式在它们附近，渗透到散装中，并最终与散装模式无法区分。我们使用Floquet扰动理论（FPT）为Floquet Hamiltonian提供了一种分析性的，尽管是扰动的表达，该理论（FPT）解释了这种现象并导致对这些特殊频率的分析表达。我们还表明，在较大的驱动幅度示范中，零能量铰链模式对应于这些特殊频率下的静态紧密结合汉密尔顿显示器在质上不同的动态。我们使用扫描隧道显微镜来讨论可能测试我们理论的局部测量密度。
We study the stroboscopic dynamics of hinge modes of a second-order topological material modeled by a tight-binding free fermion Hamiltonian on a cubic lattice in the intermediate drive frequency regime for both discrete (square pulse) and continuous (cosine) periodic drive protocols. We analyze the Floquet phases of this system and show that its quasienergy spectrum becomes almost gapless in the large drive amplitude regime at special drive frequencies. Away from these frequencies, the gapped quasienergy spectrum supports weakly dispersing Floquet hinge modes. Near them, these hinge modes penetrate into the bulk and eventually become indistinguishable from the bulk modes. We provide an analytic, albeit perturbative, expression for the Floquet Hamiltonian using Floquet perturbation theory (FPT) which explains this phenomenon and leads to analytic expressions of these special frequencies. We also show that in the large drive amplitude regime, the zero energy hinge modes corresponding to the static tight-binding Hamiltonian display qualitatively different dynamics at these special frequencies. We discuss possible local density of state measurement using a scanning tunneling microscope which can test our theory.
