标题： 三维狄拉克半金属Bi$_{0.97}$Sb$_{0.03}$中的多通道二阶拓扑态 显示英文标题

标题： Multi-channel second-order topological states in 3D Dirac semimetal Bi$_{0.97}$Sb$_{0.03}$

摘要： 第二顺序拓扑绝缘体（SOTI）状态在三维材料中的螺旋无耗散一维（1D）铰链引起了基础物理和潜在的拓扑量子计算领域的极大兴趣。 这里，我们报告了通过调节结点长度、薄片厚度和温度，在Bi$_{0.97}$Sb$_{0.03}$纳米薄片中发现的SOTI状态。我们从分数Shapiro台阶与4$\pi$周期超电流标志之间的强相关性以及铰链态的存在之间的关系中识别出高阶拓扑的特征。 紧束缚模拟确认了多个铰链模式的存在，支持我们关于Bi$_{0.97}$Sb$_{0.03}$是具有可调超导性质的典型SOTI平台的解释。 显示英文摘要

摘要： Second-order topological insulating (SOTI) states in three-dimensional materials are helical dissipation-less one-dimensional (1D) hinges, which are of great interest for fundamental physics and potential topological quantum computing. Here, we report the discovery of SOTI states in Bi$_{0.97}$Sb$_{0.03}$ nano-flakes by tuning junction length, flake thickness, and temperature. We identify signatures of higher-order topology from a strong correlation between the fractional Shapiro step, a signature of 4$\pi$-periodic supercurrent, and the presence of the hinge states. Tight-binding simulations confirm the presence of multiple hinge modes, supporting our interpretation of Bi$_{0.97}$Sb$_{0.03}$ as a prototypical SOTI platform with tunable superconducting properties.