标题： 在Bi掺杂的PbSb2Te4无序拓扑绝缘体中观察到的拓扑去局域化对抗安德森局域化 显示英文标题

标题： Topological delocalization against Anderson localization observed in Bi-doped PbSb2Te4 disordered topological insulator

摘要： 我们通过详细的输运测量实验研究了拓扑绝缘体Pb(Bi1-xSbx)2Te4 (x=0.793-0.818) 中体态和拓扑表面态的局域化倾向。 在0.793<=x<0.818范围内，体电子态位于安德森过渡的绝缘一侧，这由k_Fl值（其中k_F是费米波数，l是平均自由程）低于Ioffe-Regel判据（即，k_F l<1）所指示。 相比之下，拓扑表面态保持高迁移率，甚至表现出量子振荡，展示了它们在强无序环境下的韧性。 这些发现突显了尽管体电子态存在安德森局域化，但拓扑表面态仍然具有非局域化的性质。 显示英文摘要

摘要： We experimentally investigate the tendency of localization in the bulk and the topological surface states in topological insulators Pb(Bi1-xSbx)2Te4 (x=0.793-0.818) through detailed transport measurements. The bulk electronic states in the range 0.793<=x<0.818 are situated on the insulator side of the Anderson transition, as indicated by k_Fl values (where k_F is the Fermi wavenumber and l is the mean free path) falling below the Ioffe-Regel criterion (i.e., k_F l<1). In contrast, the topological surface states retain high mobility and even exhibit quantum oscillations, demonstrating their resilient nature against strong disorder. These findings highlight the delocalized nature of the topological surface states despite Anderson localization of the bulk electronic states.