Symmetric localization of ${\nu }_{\text{tot}}=4/3$ fractional topological insulator edges

Abstract

Motivated by the recent twisted MoTe${}_2$ experiment [arXiv:2601.18508], we develop a disordered interacting edge theory of a fractional topological insulator at ${\nu }_{\text{tot}}=4/3$, consisting of two time-reversal-conjugated $\nu =2/3$ fractional quantum Hall states. For an $S_z$-conserving edge, we uncover three distinct phases with two possible conductance values per edge in the long-edge limit: $\frac{2}{3}\frac{e^2}{h}$ and $\frac{4}{3}\frac{e^2}{h}$. In the presence of $S_z$-changing perturbations (e.g., Rashba spin-orbit coupling), an interaction-induced insulating edge state can emerge without breaking time-reversal or charge-conservation symmetry, corresponding to the absence of a topologically protected edge state. We show an exact mapping (with a special choice of parameters) to a noninteracting fermionic theory exhibiting Anderson localization, and the weak-coupling phase diagrams are also constructed, showing that symmetric localization can emerge regardless of other $S_z$-conserving perturbations. Our results showcase an explicit, experimentally relevant example that the edge-state two-terminal transport can yield false-negative results in identifying the ${\nu }_{\text{tot}}=4/3$ fractional topological insulators.

9 pages, 2 figures; published version

References in corpus (27)

• The Helical Liquid and the Edge of Quantum Spin Hall Systems
• Signatures of Fractional Quantum Anomalous Hall States in Twisted MoTe2 Bilayer
• Observation of Fractionally Quantized Anomalous Hall Effect
• Integer and fractional Chern insulators in twisted bilayer MoTe2
• Observation of integer and fractional quantum anomalous Hall effects in twisted bilayer MoTe2
• Superconducting Proximity Effect on the Edge of Fractional Topological Insulators
• Fractional topological insulators in three dimensions
• Quantum Phase Diagram of a Moiré-Hubbard Model
• Kramers Pairs of Majorana Fermions and Parafermions in Fractional Topological Insulators
• Conductivity of a generic helical liquid
• Topological Phases in AB-Stacked MoTe${}_2$/WSe${}_2$: ${\mathbb{Z}}_2$ Topological Insulators, Chern Insulators, and Topological Charge Density Waves
• Non-Abelian fractionalization in topological minibands
• Interplay between topology and correlations in the second moiré band of twisted bilayer MoTe2
• Multiple Chern bands in twisted MoTe${}_2$ and possible non-Abelian states
• Nematic excitonic insulator in transition metal dichalcogenide moiré heterobilayers
• Halperin States of Particles and Holes in Ideal Time Reversal Invariant Pairs of Chern Bands and The Fractional Quantum Spin Hall Effect in Moiré MoTe${}_2$
• Coulomb drag between helical Luttinger liquids
• Minimal Fractional Topological Insulator in half-filled conjugate moiré Chern bands
• Composite helical edges from Abelian fractional topological insulators
• Observation of Ferromagnetic Phase in the Second Moiré Band of Twisted MoTe2
• Localization and conductance in fractional quantum Hall edges
• Fractionalization as an alternate to charge ordering in electronic insulators
• Electromagnetic response and emergent topological orders in transition metal dichalcogenide MoTe${}_2$ bilayers
• Quantum Phases in Twisted Homobilayer Transition Metal Dichalcogenides
• Correlated insulator in two Coulomb-coupled quantum wires
• Drag conductance induced by neutral-mode localization in fractional quantum Hall junctions
• Dissipative Hot-spot Enabled Shock and Bounce Dynamics via Terahertz Quantum Quenches in Helical Edge States