Magnetotransport through cylindrical topological insulator (TI) nanowires is governed by the interplay between quantum confinement and geometric (Aharonov-Bohm and Berry) phases. Here, we argue that the much broader class of TI nanowires with varying radius—for which a homogeneous coaxial magnetic field induces a varying Aharonov-Bohm flux that gives rise to a nontrivial masslike potential along the wire—is accessible by studying its simplest member, a TI nanocone. Such nanocones allow us to observe intriguing mesoscopic transport phenomena: While the conductance in a perpendicular magnetic field is quantized due to higher-order topological hinge states, it shows resonant transmission through Dirac Landau levels in a coaxial magnetic field. Furthermore, it may act as a quantum magnetic bottle, confining surface Dirac electrons and leading to a largely interaction-dominated regime of Coulomb blockade type. We show numerically that the above-mentioned effects occur for experimentally accessible values of system size and magnetic field, suggesting that TI nanocone junctions may serve as building blocks for Dirac electron optics setups.

中文翻译：

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拓扑绝缘子纳米锥中的磁导，量子霍尔效应和库仑阻挡

通过圆柱形拓扑绝缘体（TI）纳米线的磁传输受量子约束和几何（Aharonov-Bohm和Berry）相之间的相互作用控制。在这里，我们认为，更广泛的类TI纳米线具有变化的半径，针对其均匀同轴磁场诱导变通过研究其最简单的元件TI纳米锥，可以访问沿导线产生非平凡的质量似电势的Aharonov-Bohm通量。此类纳米锥使我们能够观察到有趣的介观传输现象：虽然垂直磁场中的电导由于高阶拓扑铰链状态而被量化，但它却显示出同轴磁场中穿过Dirac Landau能级的共振传输。此外，它可以充当量子磁瓶，限制表面狄拉克电子，并导致很大程度上以相互作用为主导的库仑封锁型态。我们从数值上显示，上述影响发生在系统大小和磁场的实验可访问值上，这表明TI纳米锥结可以充当Dirac电子光学装置的构建基块。