In this work, we study the effects of disorder on topological metals that support a pair of helical edge modes deeply embedded inside the gapless bulk states. Strikingly, we predict that a quantum spin Hall (QSH) phase can be obtained from such topological metals without opening a global band gap. To be specific, disorder can lead to a pair of robust helical edge states which is protected by an emergent Z₂ topological invariant, giving rise to a quantized conductance plateau in transport measurements. These results are instructive for solving puzzles in various transport experiments on QSH materials that are intrinsically metallic. This work also will inspire experimental realization of the QSH effect in disordered topological metals.

中文翻译：

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二维拓扑金属中新兴的Z 2拓扑不变性和鲁棒螺旋边缘态

在这项工作中，我们研究了无序对拓扑金属的影响，这些金属支持一对深深嵌入无间隙本体内部的螺旋边缘模式。令人惊讶的是，我们预测可以从此类拓扑金属获得量子自旋霍尔（QSH）相，而无需打开全局带隙。具体而言，无序可以导致一对健壮的螺旋边缘状态，该状态由出现的Z ₂拓扑不变性保护，从而在传输测量中产生量化的电导平稳期。这些结果对于解决本质上为金属的QSH材料在各种运输实验中的难题具有指导意义。这项工作还将激发无序拓扑金属中QSH效应的实验实现。