论文标题
高阶拓扑插入隧道振荡
Higher-Order Topological Instanton Tunneling Oscillation
论文作者
论文摘要
我们提出了一种在二维高阶拓扑绝缘子中的一种新型的Instanton干扰效应。间间的隧道由激体和反互联对，它们穿过高阶拓扑绝缘子的边界。 Instanton对之间的浆果相差会导致隧道的干扰。这种拓扑作用导致闸门可调的振荡在角状态之间分裂的能量分裂，振荡性节点信号是对隧道的完美抑制。我们认为这种现象是拓扑角的独特特征，与琐碎的结合状态区分开。从实验实现的角度来看，我们体现了扭曲的双层石墨烯，这是二维高阶拓扑绝缘子的有前途的候选者。我们提出的运输实验可以很容易地观察振荡。因此，我们的工作提供了可行的途径来识别高阶拓扑材料。
We propose a new type of instanton interference effect in two-dimensional higher-order topological insulators. The intercorner tunneling consists of the instanton and the anti-instanton pairs that travel through the boundary of the higher-order topological insulator. The Berry phase difference between the instanton pairs causes the interference of the tunneling. This topological effect leads to the gate-tunable oscillation of the energy splitting between the corner states, where the oscillatory nodes signal the perfect suppression of the tunneling. We suggest this phenomenon as a unique feature of the topological corner states that differentiate from trivial bound states. In the view of experimental realization, we exemplify twisted bilayer graphene, as a promising candidate of a two-dimensional higher-order topological insulator. The oscillation can be readily observed through the transport experiment that we propose. Thus, our work provides a feasible route to identify higher-order topological materials.
