Transport through quantum spin Hall insulator/metal junctions in graphene ribbons

Abstract

Quantum spin Hall insulator/metal interfaces are formed in graphene ribbons with intrinsic spin-orbit coupling by selectively doping two regions creating a potential step. For a clean graphene ribbon, the transmission of the topological edge states through a n-n or p-p junction is perfect irrespective of the ribbon termination, width, and potential step parameters due to the orthogonality of incoming and outgoing edge channels. This is shown numerically for an arbitrary crystallographic orientation of the ribbon and proven analytically for zigzag and metallic armchair boundary conditions. In disordered ribbons, the orthogonality between left- and right-movers is in general destroyed and backscattering sets in. However, transmission approaches one by increasing the ribbon's width, even in the presence of strong edge roughness.

12 pages, 9 figures. Order of authors exchanged. Published version in the special issue of the Journal of Computational Electronics: "Electronic transport in graphene nanostructures and devices"

References in corpus (29)

• The electronic properties of graphene
• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• Chiral tunneling and the Klein paradox in graphene
• Electronic States of Graphene Nanoribbons
• Bipolar supercurrent in graphene
• Quantum interference and Klein tunneling in graphene heterojunctions
• Intrinsic and Rashba Spin-orbit Interactions in Graphene Sheets
• Veselago Lens for Electrons: Focusing and Caustics in Graphene p-n Junctions
• Spin-orbit coupling in curved graphene, fullerenes, nanotubes, and nanotube caps
• Spin-orbit gap of graphene: First-principles calculations
• Evidence for Helical Edge Modes in Inverted InAs/GaSb Quantum Wells
• Nonlocal edge state transport in the quantum spin Hall state
• Specular Andreev reflection in graphene
• Phase Coherent Transport of Charges in Graphene Quantum Billiard
• Conductance quantization and transport gap in disordered graphene nanoribbons
• Graphene Spin Transistor
• Proximity effect at the superconductor - topological insulator interface
• Giant topological insulator gap in graphene with 5d adatoms
• Tunneling between edge states in a quantum spin Hall system
• Spin-resolved scattering through spin-orbit nanostructures in graphene
• Band topology and quantum spin Hall effect in bilayer graphene
• Probing the helical edge states of a topological insulator by Cooper-pair injection
• Zero Landau level in folded graphene nanoribbons
• Microwave-driven ferromagnet--topological-insulator heterostructures: The prospect for giant spin battery effect and quantized charge pump devices
• Inducing topological order in a honeycomb lattice
• Intrinsic spin-orbit interactions in flat and curved graphene nanoribbons
• Mesoscopic spin Hall effect along a potential step in graphene
• Spin-filtered edge states in graphene

Cited by in corpus (11)

• Helical networks in twisted bilayer graphene under interlayer bias
• Correlation-driven topological phase transition from in-plane magnetized quantum anomalous Hall to Mott insulating phase in monolayer transition metal trichlorides
• Giant thermoelectric effect in graphene-based topological insulators with nanopores
• Charge transport in pn and npn junctions of silicene
• Origin of nonlocal resistance in multiterminal graphene on hexagonal-boron-nitride: Fermi surface edge currents rather than Fermi sea topological valley currents
• Multiple Quantum Phases in Graphene with Enhanced Spin-Orbit Coupling: From the Quantum Spin Hall Regime to the Spin Hall Effect and a Robust Metallic State
• Tunable thermopower in a graphene-based topological insulator
• The fundamental differences between Quantum Spin Hall edge-states at zig-zag and armchair terminations of honeycomb and ruby nets
• Effects of Defects and Dephasing on Charge and Spin Currents in Two-Dimensional Topological Insulators
• Robustness of quantized transport through edge states of finite length: Imaging current density in Floquet topological vs. quantum spin and anomalous Hall insulators
• Controlling the Flow of Spin and Charge in Nanoscopic Topological Insulators