Robustness of Helical Edge States Under Edge Reconstruction

Abstract

The helical edge states of time-reversal invariant two-dimensional topological insulators are protected against backscattering in idealized models. In more realistic scenarios with a shallow confining potential at the sample boundary, additional strongly interacting edge states may arise, that could interfere with the topological protection of edge conduction. We find that interaction effects within the reconstructed edges are well described by the Luttinger liquid model. While interactions between this Luttinger liquid and the helical edge states can in principle give rise to dynamical spin polarization and the breaking of time-reversal symmetry, we demonstrate that random spin-orbit coupling strongly suppresses such dynamical spin polarization, resulting in the persistence of near quantized edge conduction.

12 pages, 3 figures; updated figures and extended supplemental material

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Cited by in corpus (6)

• Emergence of Neutral Modes in Laughlin-like Fractional Quantum Hall Phases
• Multiple Mechanisms for Emerging Conductance Plateaus in Fractional Quantum Hall States
• Edge Reconstruction of a Time-Reversal Invariant Insulator: Compressible-Incompressible Stripes
• Topological and magnetic properties of the interacting Bernevig-Hughes-Zhang model
• Experimentally Motivated Order of Length Scales Affect Shot Noise
• Edge Reconstruction in a Quantum Spin Hall Insulator