论文标题
拓扑和边缘状态在拓扑绝缘子之间幸存下来
Topology and edge states survive quantum criticality between topological insulators
论文作者
论文摘要
人们经常认为，在调谐到临界点时，物质拓扑阶段的新兴现象被破坏。特别是，当散装相关长度差异时，拓扑保护的边缘状态据说是DELEACAL的。我们表明，这一般情况并非如此。拓扑绝缘子或超导体的边缘状态仍然定位 - 尽管带隙消失了 - 如果过渡增加了拓扑指数。这适用于拓扑分类大于$ z_2 $的所有类，尤其是包括Chern绝缘子。此外，与拓扑半金属不同，这些边缘状态与无序稳定。这种新现象是通过概括（或质量）反转来解释的，这是对拓扑绝缘子的统一观点 - - 转化为动力学反转。本着庞大的对应关系的精神，我们还确定了临界时的拓扑不变性，这些拓扑不变性的价值观和单独的拓扑赋予普遍性类别通过多临界点。这项工作通过表明不必要的散装能量差距来扩大拓扑保护和稳定性的范围。讨论了实验探针和相互作用的稳定性。
It is often thought that emergent phenomena in topological phases of matter are destroyed when tuning to a critical point. In particular, topologically protected edge states supposedly delocalize when the bulk correlation length diverges. We show that this is not true in general. Edge states of topological insulators or superconductors remain exponentially localized---despite a vanishing band gap---if the transition increases the topological index. This applies to all classes where the topological classification is larger than $Z_2$, notably including Chern insulators. Moreover, these edge states are stable to disorder, unlike in topological semi-metals. This new phenomenon is explained by generalizing band (or mass) inversion---a unifying perspective on topological insulators---to kinetic inversion. In the spirit of the bulk-boundary correspondence, we also identify topological invariants at criticality, which take half-integer values and separate topologically-distinct universality classes by a multi-critical point. This work enlarges the scope of topological protection and stability by showing that bulk energy gaps can be unnecessary. Experimental probes and stability to interactions are discussed.
