Nuclear-Spin-Induced Resistance of the Edge States in Two-Dimensional Topological Insulators Chen-Hsuan Hsu ^{1*}, Peter Stano^{1,2}, Jelena Klinovaja^{1,3}, Daniel Loss^{1,3}^{1}Center for Emergent Matter Science, RIKEN, Wako, Japan^{2}Institute of Physics, Slovak Academy of Sciences, Bratislava, Slovak Republic^{3}Department 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). [2] B. Braunecker, P. Simon, and D. Loss, Phys. Rev. Lett. 102, 116403 (2009). [3] B. Braunecker, P. Simon, and D. Loss, Phys. Rev. B 80, 165119 (2009). [4] J. Klinovaja, P. Stano, A. Yazdani, and D. Loss, Phys. Rev. Lett. 111, 186805 (2013) [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 |