Single-edge transport in an InAs/GaSb quantum spin Hall insulator

Abstract

We report transport measurements in a single edge channel of an InAs/GaSb quantum spin Hall insulator, where the conduction occurs through only one pair of counterpropagating edge modes. By using a specific sample design involving highly asymmetric current paths, we electrically isolate a single edge channel of the two-dimensional topological insulator from the other edge. This enables us to probe a single edge by multiterminal measurements. Both two-terminal and four-terminal resistances show a nearly quantized plateau around $h/e^2$ for a 4-$\mu$m-long edge, indicating quasiballistic transport. Our approach is advantageous in that it allows us to gain insight into a microscopic region from local measurements.

5 pages, 5 figures

References in corpus (13)

• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• Nonlocal edge state transport in the quantum spin Hall state
• Quantum Spin Hall Effect in Inverted Type II Semiconductors
• The Helical Liquid and the Edge of Quantum Spin Hall Systems
• Kondo effect in the helical edge liquid of the quantum spin Hall state
• Edge-mode Superconductivity in a Two Dimensional Topological Insulator
• Edge Dynamics in a Quantum Spin Hall State: Effects from Rashba Spin-Orbit Interaction
• Fermion-parity anomaly of the critical supercurrent in the quantum spin-Hall effect
• Spatially resolved study of backscattering in the quantum spin Hall state
• Persistence of two-dimensional topological insulator state in wide HgTe quantum well
• Helical edge states coupled to a spin bath: Current-induced magnetization
• The Coexistence and Decoupling of Bulk and Edge States in Disordered Two-dimensional Topological Insulators

Cited by in corpus (6)

• Engineering quantum spin Hall insulators by strained-layer heterostructures
• Low-Temperature Conductivity of Weakly Interacting Quantum Spin Hall Edges in Strained-Layer InAs/GaInSb
• Current noise from a magnetic moment in a helical edge
• Localization of trivial edge states in InAs/GaSb composite quantum wells
• Impact of epitaxial strain on the topological-nontopological phase diagram and semimetallic behavior of InAs/GaSb composite quantum wells
• Finite-temperature spectroscopy of dirty helical Luttinger liquids