2026-06-07T23:48:51Zhttps://docta.ucm.es/rest/oai/requestoai:docta.ucm.es:20.500.14352/245702023-07-18T03:03:36Zcom_20.500.14352_14col_20.500.14352_15
Docta Complutense
author
Ortiz Martín, Laura
author
Molina Fernández, Rafael Alejandro
2023-06-18T06:54:52Z
2023-06-18T06:54:52Z
2016-05-20
2469-9950
10.1103/PhysRevB.93.205431
https://hdl.handle.net/20.500.14352/24570
http://dx.doi.org/10.1103/PhysRevB.93.205431
http://journals.aps.org/
We study the helical edge states of a two-dimensional topological insulator without axial spin symmetry due to the Rashba spin-orbit interaction. Lack of axial spin symmetry can lead to so-called generic helical edge states, which have energy-dependent spin orientation. This opens the possibility of inelastic backscattering and thereby nonquantized transport. Here we find analytically the new dispersion relations and the energy dependent spin orientation of the generic helical edge states in the presence of Rashba spin-orbit coupling within the Bernevig-Hughes-Zhang model, for both a single isolated edge and for a finite width ribbon. In the single-edge case, we analytically quantify the energy dependence of the spin orientation, which turns out to be weak for a realistic HgTe quantum well. Nevertheless, finite size effects combined with Rashba spin-orbit coupling result in two avoided crossings in the energy dispersions, where the spin orientation variation of the edge states is very significantly increased for realistic parameters. Finally, our analytical results are found to compare well to a numerical tight-binding regularization of the model.
spa
Generic helical edge states due to Rashba spin-orbit coupling in a topological insulator
journal article
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https://docta.ucm.es/bitstreams/f5d91445-69e5-40b3-a6da-285c6e03815c/download
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1886101
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OrtizMartínL 01 libre.pdf