Interacting topological edge channels

Abstract

Electrical currents in a quantum spin Hall insulator are confined to the boundary of the system. The charge carriers can be described as massless relativistic particles, whose spin and momentum are coupled to each other. While the helical character of those states is by now well established experimentally, it is a fundamental open question how those edge states interact with each other when brought in spatial proximity. We employ a topological quantum point contact to guide edge channels from opposite sides into a quasi-one-dimensional constriction, based on inverted HgTe quantum wells. Apart from the expected quantization in integer steps of $2e^2/h$, we find a surprising additional plateau at $e^2/h$. We explain our observation by combining band structure calculations and repulsive electron-electron interaction effects captured within the Tomonaga-Luttinger liquid model. The present results may have direct implications for the study of one-dimensional helical electron quantum optics, Majorana- and potentially para-fermions.

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• Universal duality transformations in interacting one-dimensional quantum systems
• Optimal thermoelectricity with quantum spin-Hall edge states
• Conductance of quantum spin Hall edge states from first principles: the critical role of magnetic impurities and inter-edge scattering
• Formation and detection of Majorana modes in quantum spin Hall trenches
• Charge, spin, and heat shot noises in the absence of average currents: Conditions on bounds at zero and finite frequencies
• A robust and tunable Luttinger liquid in correlated edge of transition-metal second-order topological insulator Ta${}_2$Pd${}_3$Te${}_5$
• Does delta-$T$ noise probe quantum statistics?
• Quasiparticle poisoning effects on the dynamics of topological Josephson junctions
• Majorana-like localized spin density without bound states in topologically trivial spin-orbit coupled nanowires
• Emerging topological bound states in Haldane model zigzag nanoribbons
• Coherent spin transport through helical edge states of topological insulator
• Fabry-Pérot resonant vortices and magnetoconductance in topological insulator constrictions with magnetic barriers
• Living on the edge: Topology, electrostatics and disorder
• Breakdown of helical edge state topologically protected conductance in time-reversal-breaking excitonic insulators
• Platforms for the realization and characterization of Tomonaga-Luttinger liquids
• Theory of Glide Symmetry Protected Helical Edge States in WTe${}_2$ Monolayer
• Tomonaga Luttinger liquid in the topological edge channel of multilayer FeSe
• Moving Majorana bound states between distinct helical edges across a quantum point contact
• Velocity and confinement of edge plasmons in HgTe-based 2D topological insulators
• Reconstruction-Induced ${\phi }_0$ Josephson Effect in Quantum Spin Hall Constrictions
• Detailed study of nonlinear cooling with two-terminal configurations of topological edge states
• Transport signatures of a Floquet topological transition at the helical edge
• Robustness of Helical Edge States Under Edge Reconstruction
• Fraunhofer pattern in the presence of Majorana zero modes
• Localization of the Helical Edge States in the Absense of External Magnetic Field
• Spin Berry phase in a helical edge state: Sz nonconservation and transport signatures
• Dual topological insulator with mirror symmetry protected helical edge states
• Effects of the Spatial Extension of the Edge Channels on the Interference Pattern of a Helical Josephson Junction
• Spin-resolved spectroscopy of helical Andreev bound states
• Universal transparency and fine band structure near the Dirac point in HgTe quantum wells
• Backscattering off a driven Rashba impurity at the helical edge
• Interference effects induced by a precessing easy-plane magnet coupled to a helical edge state
• Assessing bound states in a one-dimensional topological superconductor: Majorana versus Tamm
• Confinement versus interface bound states in spin-orbit coupled nanowires
• Random-gate-voltage induced Al'tshuler-Aronov-Spivak effect in topological edge states
• Anomalous flux periodicity in proximitised quantum spin Hall constrictions
• Dissipative Hot-spot Enabled Shock and Bounce Dynamics via Terahertz Quantum Quenches in Helical Edge States
• Anomalous conductance steps in three-dimensional topological insulator HgTe-based quantum point contacts
• Spin responses of a disordered helical superconducting edge under Zeeman field
• Edge Reconstruction in a Quantum Spin Hall Insulator