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arXiv · 2401.11157

Quasiparticle scattering in three-dimensional topological insulators near the thickness limit

Haiming Huang·Mu Chen·Dezhi Song·Jun Zhang·Ye-ping Jiang
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Abstract

In the ultra-thin regime, Bi2Te3 films feature two surfaces (with each surface being a two-dimensional Dirac-fermion system) with complicated spin textures and a tunneling term between them. We find in this regime that the quasiparticle scattering is completely different compared with the thick-film case and even behaves differently at each thickness. The thickness-dependent warping effect and tunneling term are found to be the two main factors that govern the scattering behaviors. The inter-band back-scattering that signals the existence of a tunneling term is found to disappear at 4 quintuple layers by the step-edge reflection approach. A four-band model is presented that captures the main features of the thickness-dependent scattering behaviors. Our work clarifies that the prohibition of back-scattering guaranteed by symmetry in topological insulators breaks down in the ultra-thin regime.

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Haiming Huang, Mu Chen, Dezhi Song, Jun Zhang, Ye-ping Jiang. 2024-01-20. Quasiparticle scattering in three-dimensional topological insulators near the thickness limit. https://doi.org/10.1103/physrevb.109.115414

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