Nuclear-Spin-Induced Resistance of the Edge States in Two-Dimensional Topological Insulators
Chen-Hsuan Hsu1*, Peter Stano1,2, Jelena Klinovaja1,3, Daniel Loss1,3
1Center for Emergent Matter Science, RIKEN, Wako, Japan
2Institute of Physics, Slovak Academy of Sciences, Bratislava, Slovak Republic
3Department of Physics, University of Basel, Basel, Switzerland
* Presenter:Chen-Hsuan Hsu, email:chenhsuan.hsu@gmail.com
We investigate the effects of the nuclear spins on the edge resistance of a two-dimensional topological insulator (2DTI) [1]. The nuclear spins couple to the edge-state electrons via the hyperfine interaction. In the disordered phase, the nuclear spins are randomly oriented, and allow elastic spin-flip backscattering between the edge electrons. At sufficiently low temperatures, on the other hand, the nuclear spins may form an order [2-6], as a result of the RKKY interaction mediated by the edge electrons. We demonstrate that such ordering induces a macroscopic magnetic (Overhauser) field, and causes the field-assisted backscattering on charge impurities, in addition to the magnon-mediated backscattering. We perform the renormalization-group analysis to investigate the resistance resulting from these backscattering mechanisms. Finally, we take InAs/GaSb 2DTI as an example to make estimation on the edge resistance, as well as the experimental conditions to observe such a resistance.

References
[1] C.-H. Hsu, P. Stano, J. Klinovaja, and D. Loss, Phys. Rev. B 96, 081405(R) (2017).
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[3] B. Braunecker, P. Simon, and D. Loss, Phys. Rev. B 80, 165119 (2009).
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[5] T. Meng, P. Stano, J. Klinovaja, and D. Loss, Eur. Phys. J. B 87, 203 (2014).
[6] C.-H. Hsu, P. Stano, J. Klinovaja, and D. Loss, Phys. Rev. B 92, 235435 (2015).


Keywords: topological insulator, transport properties, Tomonaga-Luttinger liquid, electron-electron interaction, renormalization group