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arXiv · 2008.03919

Weak localization and anti-localization in rare earth doped topological insulators

Zengji Yue·Kirrily Rule·Zhi Li·Weiyao Zhao·Lina Sang·Guangsai Yang·Cheng Tan·Lan Wang·Abuduliken Bake·Xiaolin Wang
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Abstract

We study magneto-transport phenomena in two rare-earth doped topological insulators, SmxFexSb2-2xTe3 and SmxBi2-xTe2Se single crystals. The magneto-transport behaviours in both compounds exhibit a systematic crossover between weak anti-localization (positive magnetoresistance) and weak localization (negative magnetoresistance) with changes in temperatures and magnetic fields. The weak localization is caused by rare-earth-doping induced magnetization, and the weak anti-localization originates from topologically protected surface states. The transition between weak localization and weak anti-localization demonstrates a gap opening at the Dirac point of surface states in the quantum diffusive regime. This work demonstrates an effective way to manipulate the magneto-transport properties of the topological insulators by rare-earth element doping. Magnetometry measurements indicate that the Sm-dopant alone is paramagnetic, whereas the co-doped Fe-Sm state has short-range antiferromagnetic order. Our results hold potential for the realization of exotic topological effects in gapped topological insulator surface states.

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Zengji Yue, Kirrily Rule, Zhi Li, Weiyao Zhao, Lina Sang, Guangsai Yang, Cheng Tan, Lan Wang, Abuduliken Bake, Xiaolin Wang. 2020-08-10. Weak localization and anti-localization in rare earth doped topological insulators. https://arxiv.org/abs/2008.03919

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