School of Physical Sciences, National Institute of Science Education & Research, HBNI, Jatni, 752050, India.
Sci Rep. 2018 Jan 22;8(1):1335. doi: 10.1038/s41598-018-19272-7.
Although indications are that a single chiral quantum anomalous Hall(QAH) edge mode might have been experimentally detected. There have been very many recent experiments which conjecture that a chiral QAH edge mode always materializes along with a pair of quasi-helical quantum spin Hall (QSH) edge modes. In this work we deal with a substantial 'What If?' question- in case the QSH edge modes, from which these QAH edge modes evolve, are not topologically-protected then the QAH edge modes wont be topologically-protected too and thus unfit for use in any applications. Further, as a corollary one can also ask if the topological-protection of QSH edge modes does not carry over during the evolution process to QAH edge modes then again our 'What if?' scenario becomes apparent. The 'how' of the resolution of this 'What if?' conundrum is the main objective of our work. We show in similar set-ups affected by disorder and inelastic scattering, transport via trivial QAH edge mode leads to quantization of Hall resistance and not that via topological QAH edge modes. This perhaps begs a substantial reinterpretation of those experiments which purported to find signatures of chiral(topological) QAH edge modes albeit in conjunction with quasi helical QSH edge modes.
尽管有迹象表明，单个手性量子反常霍尔(QAH)边缘模式可能已经在实验中被检测到。但最近有很多实验推测，手性 QAH 边缘模式总是伴随着一对准螺旋量子自旋霍尔(QSH)边缘模式而出现。在这项工作中，我们处理了一个实质性的“假设”问题——如果 QSH 边缘模式不是拓扑保护的，那么这些 QAH 边缘模式也不会是拓扑保护的，因此不适合在任何应用中使用。此外，作为推论，人们还可以问，如果 QSH 边缘模式的拓扑保护在演化过程中不会传递到 QAH 边缘模式，那么我们的“假设”情况再次变得明显。解决这个“假设”难题的“方法”是我们工作的主要目标。我们在受无序和非弹性散射影响的类似设置中表明，通过平凡的 QAH 边缘模式进行输运导致霍尔电阻的量子化，而不是通过拓扑 QAH 边缘模式进行输运。这或许需要对手持声称发现手性（拓扑）QAH 边缘模式特征的实验进行实质性的重新解释，尽管这些实验是与准螺旋 QSH 边缘模式一起进行的。
