论文标题
激光诱导的拓扑$ S $ - 双层过渡金属二分法中的超导率
Laser-induced topological $s$-wave superconductivity in bilayer transition metal dichalcogenides
论文作者
论文摘要
在本文中，我们提出了一种实现拓扑$ s $波超导性的方法，并在二维双层过渡金属二核苷（TMDS）中应用圆形极化激光光（TMDS）。使用浮雕理论，我们分析了具有时间周期性电场的双层TMD的紧密结合模型。得出有效的哈密顿量后，我们研究了$ S $波超导状态的拓扑特性。激光灯诱导山谷依赖性层极化，并使系统成为以Chern数为特征的拓扑非平凡的超导状态。在不存在和存在Kane-Mele自旋轨道耦合的情况下，我们显示了拓扑相图，该耦合导致双层TMD中隐藏的自旋极化。尽管拓扑相图受自旋轨道耦合的影响，但可以实现拓扑超导性，而无需依靠与先前激光诱导的拓扑超导性的建议形成鲜明对比的自旋轨道耦合[K。 takasan，\ textit {et al。}，phys。 Rev. B \ TextBf {95}，134508（2017）]。我们还讨论了检测拓扑阶段的实验设置。
In this paper, we propose a way to realize topological $s$-wave superconductivity with application of circularly polarized laser light in two-dimensional bilayer transition metal dichalcogenides (TMDs). Using Floquet theory, we analyze a tight-binding model of bilayer TMDs with time-periodic electric fields. After deriving an effective Hamiltonian, we investigate topological properties of the $s$-wave superconducting state. The laser light induces valley-dependent layer polarization and makes the system to be a topologically nontrivial superconducting state characterized by the Chern number. We show topological phase diagrams in the absence and presence of the Kane-Mele spin-orbit coupling which causes hidden spin polarization in bilayer TMDs. Although the topological phase diagram is affected by the spin-orbit coupling, topological superconductivity can be realized without relying on the spin-orbit coupling in sharp contrast to a previous proposal of laser-induced topological superconductivity [K. Takasan, \textit{et al.}, Phys. Rev. B \textbf{95}, 134508 (2017)]. We also discuss experimental setups to detect the topological phase.
