Sub-nm wide electron channels protected by topology

Abstract

Helical locking of spin and momentum and prohibited backscattering are the key properties of topologically protected states. They are expected to enable novel types of information processing such as spintronics by providing pure spin currents, or fault tolerant quantum computation by using the Majorana fermions at interfaces of topological states with superconductors. So far, the required helical conduction channels used to realize Majorana fermions are generated through application of an axial magnetic field to conventional semiconductor nanowires. Avoiding the magnetic field enhances the possibilities for circuit design significantly. Here, we show that sub-nanometer wide electron channels with natural helicity are present at surface step-edges of the recently discovered topological insulator Bi14Rh3I9. Scanning tunneling spectroscopy reveals the electron channels to be continuous in both energy and space within a large band gap of 200 meV, thereby, evidencing its non-trivial topology. The absence of these channels in the closely related, but topologically trivial insulator Bi13Pt3I7 corroborates the channels' topological nature. The backscatter-free electron channels are a direct consequence of Bi14Rh3I9's structure, a stack of 2D topologically insulating, graphene-like planes separated by trivial insulators. We demonstrate that the surface of Bi14Rh3I9 can be engraved using an atomic force microscope, allowing networks of protected channels to be patterned with nm precision.

17 pages, 4 figures, and supplementary material, Nature Physics in press

References in corpus (8)

• The electronic properties of graphene
• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• Topological Insulators with Inversion Symmetry
• Signatures of Majorana fermions in hybrid superconductor-semiconductor nanowire devices
• Three dimensional topological invariants for time reversal invariant Hamiltonians and the three dimensional quantum spin Hall effect
• Finite size effects of helical edge states in HgTe/CdTe quantum wells
• One-dimensional Topological Edge States of Bismuth Bilayers
• Stacked topological insulator built from bismuth-based graphene sheet analogues

Cited by in corpus (78)

• Colloquium: Topological Band Theory
• Realization of Quantum Spin Hall State in Monolayer 1T'-WTe2
• Electronic Evidence of Temperature-Induced Lifshitz Transition and Topological Nature in ZrTe5
• Topological Materials Discovery from Crystal Symmetry
• Robust topological edge states at the perfect surface step edge of topological insulator ZrTe${}_5$
• Observation of topological states residing at step edges of WTe2
• Discovery of switchable weak topological insulator state in quasi-one-dimensional bismuth iodide
• Observation of Topologically Protected States at Crystalline Phase Boundaries in Single-layer WSe2
• Experimental evidence of large-gap two-dimensional topological insulator on the surface of ZrTe5
• Direct Visualization of 2D Topological Insulator in Single-layer 1T'-WTe2
• Probing topological quantum matter with scanning tunnelling microscopy
• Robust spin-polarized midgap states at step edges of topological crystalline insulators
• Room-temperature quantum spin Hall edge state in a higher-order topological insulator Bi${}_4$Br${}_4$
• Tomonaga-Luttinger liquid in the edge channels of a quantum spin Hall insulator
• Discovery of charge order and corresponding edge state in kagome magnet FeGe
• Aperiodic Weak Topological Superconductors
• Weak Topological Insulators and Composite Weyl Semimetals: $\beta$-Bi${}_4$X${}_4$ (X=Br, I)
• $\mbox{Bi}_{1}\mbox{Te}_{1}$: a dual topological insulator
• Emergence of topological bands on the surface of ZrSnTe crystal
• Observation of Coulomb gap in the quantum spin Hall candidate single-layer 1T'-WTe${}_2$
• Scattering matrix invariants of Floquet topological insulators
• Enhancement of superconductivity in organic-inorganic hybrid topological materials
• Signature of large-gap quantum spin Hall state in the layered mineral jacutingaite
• Partial lattice defects in higher order topological insulators
• Topological Mirror Insulators in One Dimension
• Topological origin of edge states in two-dimensional inversion-symmetric insulators and semimetals
• Evidence for a quantum-spin-Hall phase in graphene decorated with Bi2Te3 nanoparticles
• Topological Edge States with Zero Hall Conductivity in a Dimerized Hofstadter Model
• Testing Topological Protection of Edge States in Hexagonal Quantum Spin Hall Candidate Materials
• Generic coexistence of Fermi arcs and Dirac cones on the surface of time-reversal invariant Weyl semimetals
• Bulk characterization of topological crystalline insulators: stability under interactions and relations to symmetry enriched U(1) quantum spin liquids
• Trapped state at a dislocation in a weak magnetomechanical topological insulator
• Transport response of topological hinge modes in $\alpha$-Bi${}_4$Br${}_4$
• Experimental realization of two-dimensional weak topological insulators
• Weak-link Josephson Junctions Made from Topological Crystalline Insulators
• Infinite Projected Entangled-Pair State algorithm for ruby and triangle-honeycomb lattices
• Discovery of a hybrid topological quantum state in an elemental solid
• Discovery of a weak topological insulating state and van Hove singularity in triclinic RhBi2
• First principles feasibility assessment of a topological insulator at the InAs/GaSb interface
• Epitaxial Growth of Quasi-One-Dimensional Bismuth-Halide Chains with Topological Non-Trivial Edge States
• Pure spin current devices based on ferromagnetic topological insulators
• Robustness of Helical Hinge States of Weak Second-Order Topological Insulators
• Anomalous Quasiparticle Symmetries and Non-Abelian Defects on Symmetrically Gapped Surfaces of Weak Topological Insulators
• Evidence of topological edge states in a superconducting nonsymmorphic nodal-line semimetal
• Topological spin liquids in the ruby lattice with anisotropic Kitaev interactions
• Anomalous Floquet topological crystalline insulators
• 2D and 3D topological phases in BiTe$X$ compounds
• Spatially resolved Landau level spectroscopy of the topological Dirac cone of bulk-type Sb2Te3(0001): potential fluctuations and quasiparticle lifetime
• Topological ${\mathbb{Z}}_2$ RVB quantum spin liquid on the ruby lattice
• A Systematic Investigation of the Coupling between One-Dimensional Edge States of a Topological Crystalline Insulator
• Optical bulk-boundary dichotomy in a quantum spin Hall insulator
• Experimental observations indicating the topological nature of the edge states on HfTe5
• Correlation between topological band character and chemical bonding in a $\mathbf{B}{\mathbf{i}}_{14}\mathbf{R}{\mathbf{h}}_3{\mathbf{I}}_9$-based family of insulators
• Probing edge state conductance in ultra-thin topological insulator films
• Atoms to topological electronic materials: A bedtime story for beginners
• Persistent current due to a screw dislocation in Weyl semimetals: Role of one-dimensional chiral states
• Topological end states due to inhomogeneous strains in wrinkled semiconducting ribbons
• Mass Acquisition of Dirac Fermions in Bi4I4 by Spontaneous Symmetry Breaking
• Chemical Gating of a Weak Topological Insulator: Bi14Rh3I9
• STM observation of the hinge-states of bismuth nanocrystals
• Spin-polarized tunneling into helical edge states: asymmetry and conductances
• Chern number spectrum of ultra-cold fermions in optical lattices tuned independently via artificial magnetic, Zeeman and spin-orbit fields
• Synthesizing Weyl semimetals in weak topological insulator and topological crystalline insulator multilayers
• Strong and Weak Three-Dimensional Topological Insulators Probed by Surface Science Methods
• Weak topological insulating phases of hard-core-bosons on the honeycomb lattice
• Conductivity of Dirac-like surface states in correlated honeycomb transition metal oxide Mott insulators
• Numerical analysis of surface and edge states in slabs, stripes, rods and surface steps of topological insulators
• Coexisting surface states in the weak and crystalline topological insulator Bi_2TeI
• Experimental Observation of Bound States of 2D Dirac Electrons at Surface Steps of the Topological Insulator Bi${}_2$Se${}_3$
• Chiral surface states on the step edge in a Weyl semimetal
• Weak topological insulators with step edges: Subband engineering and its effect on electron transport
• Electronic Structure of the Dark Surface of the Weak Topological Insulator Bi14Rh3I9
• Landau levels on a surface of weak topological insulators
• Distributed Current Injection into a One-Dimensional Ballistic Edge Channel
• Emergent One-Dimensional Helical Channel in Higher-Order Topological Insulators with Step Edges
• Strongly Correlated Transport in Topological Y-Junction Devices
• Crystalline Weyl semimetal phase in Quantum Spin Hall systems under magnetic fields
• Simplex Crystal Ground State and Magnetization Plateaus in the Spin-$1/2$ Heisenberg Model on the Ruby Lattice