Title

Cross-over from weak localization to anti-localization in rare doped TRS protected topological insulators

Publication Name

Physics Letters, Section A: General, Atomic and Solid State Physics

Abstract

We study magneto-transport phenomena in two rare-earth doped topological insulators, Sm Fe Sb Te and Sm Bi Te Se single crystals. The magneto-transport behaviours in both compounds exhibit a novel 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 from weak localization to weak anti-localization demonstrates a gap opening at the Dirac point of the 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 demonstrate the potential to realize exotic topological effects and magneto-electric effects in gapped surface states of rare earth doped topological insulators. x x 2-2x 3 x 2-x 2

Open Access Status

This publication is not available as open access

Volume

385

Article Number

126953

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Link to publisher version (DOI)

http://dx.doi.org/10.1016/j.physleta.2020.126953