Gigantic negative magnetoresistance in the bulk of a disordered topological insulator

被引：83

作者：

Breunig, Oliver ^{[1
]}

Wang, Zhiwei ^{[1
]}

Taskin, A. A. ^{[1
]}

Lux, Jonathan ^{[2
]}

Rosch, Achim ^{[2
]}

Ando, Yoichi ^{[1
]}

机构：

[1] Univ Cologne, Phys Inst 2, Zulpicher Str 77, D-50937 Cologne, Germany

[2] Univ Cologne, Inst Theoret Phys, Zulpicher Str 77, D-50937 Cologne, Germany

来源：

NATURE COMMUNICATIONS | 2017年 / 8卷

关键词：

CONDUCTIVITY; TLSBTE2;

D O I：

10.1038/ncomms15545

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

With the recent discovery of Weyl semimetals, the phenomenon of negative magnetoresistance (MR) is attracting renewed interest. Large negative MR is usually related to magnetism, but the chiral anomaly in Weyl semimetals is a rare exception. Here we report a mechanism for large negative MR which is also unrelated to magnetism but is related to disorder. In the nearly bulk-insulating topological insulator TlBi0.15Sb0.85Te2, we observed gigantic negative MR reaching 98% in 14 T at 10 K, which is unprecedented in a nonmagnetic system. Supported by numerical simulations, we argue that this phenomenon is likely due to the Zeeman effect on a barely percolating current path formed in the disordered bulk. Since disorder can also lead to non-saturating linear MR in Ag-2 (+) Se-delta, the present finding suggests that disorder engineering in narrow-gap systems is useful for realizing gigantic MR in both positive and negative directions.

引用

页数：7

共 38 条

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