Transport through the network of topological channels in HgTe based quantum well

Abstract

Topological insulators represent a new quantum state of matter which is characterized by edge or surface states and an insulating band gap in the bulk. In a two dimensional (2D) system based on the HgTe quantum well (QW) of critical width random deviations of the well width from its average value result in local crossovers from zero gap 2D Dirac fermion system to either the 2D topological insulator or the ordinary insulator, forming a complicated in-plane network of helical channels along the zero-gap lines. We have studied experimentally the transport properties of the critical width HgTe quantum wells near the Dirac point, where the conductance is determined by a percolation along the zero-gap lines. The experimental results confirm the presence of percolating conducting channels of a finite width. Our work establishes the critical width HgTe QW as a promising platform for the study of the interplay between topology and localization.

7 pages, 5 figures

References in corpus (11)

• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• Nonlocal edge state transport in the quantum spin Hall state
• Topological Anderson Insulator
• Electron transport in disordered graphene
• Tuning the effective fine structure constant in graphene: opposing effects of dielectric screening on short- and long-range potential scattering
• Single valley Dirac fermions in zero-gap HgTe quantum wells
• Two-dimensional spin-filtered chiral network model for the Z_2 quantum spin-Hall effect
• Persistence of two-dimensional topological insulator state in wide HgTe quantum well
• Boundary criticality at the Anderson transition between a metal and a quantum spin Hall insulator in two dimensions
• Robust helical edge transport at $\nu =0$ quantum Hall state
• Supersymmetry approach to delocalization transitions in a network model of the weak field quantum Hall effect and related models

Cited by in corpus (4)

• Interaction dominated transport in 2D conductors: from degenerate to partially-degenerate regime
• Quantum transport of Dirac fermions in HgTe gapless quantum wells
• Magnetotransport in a 2D Hybrid Band System: Dirac and Heavy Hole Interplay
• Interaction Induced Magnetotransport in a 2D Dirac-Heavy Hole Hybrid Band System