Disorder enabled band structure engineering of a topological insulator surface

Abstract

Three dimensional topological insulators are bulk insulators with ${\mathbf{Z}}_2$ topological electronic order that gives rise to conducting light-like surface states. These surface electrons are exceptionally resistant to localization by non-magnetic disorder, and have been adopted as the basis for a wide range of proposals to achieve new quasiparticle species and device functionality. Recent studies have yielded a surprise by showing that in spite of resisting localization, topological insulator surface electrons can be reshaped by defects into distinctive resonance states. Here we use numerical simulations and scanning tunneling microscopy data to show that these resonance states have significance well beyond the localized regime usually associated with impurity bands. At native densities in the model Bi${}_2$X${}_3$ (X=Bi, Te) compounds, defect resonance states are predicted to generate a new quantum basis for an emergent electron gas that supports diffusive electrical transport.

References in corpus (13)

• Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
• Topological Field Theory of Time-Reversal Invariant Insulators
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• Topological Surface States Protected From Backscattering by Chiral Spin Texture
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• Quantum criticality and minimal conductivity in graphene with long-range disorder
• Z2 topological term, the global anomaly, and the two-dimensional symplectic symmetry class of Anderson localization
• Quasiparticle Dynamics in Reshaped Helical Dirac Cone of Topological Insulators
• Stationary phase approximation approach to the quasiparticle interference on the surface of a strong topological insulator
• Spontaneous gap generation on the surface of weakly interacting topological insulators using nonmagnetic impurities
• Effect of surface defects and few-atomic steps on the local density of states of the atomically-clean surface of topological insulator Bi${}_2$Se${}_3$
• Anisotropic Fabry-Pérot resonant states confined within nano-steps on the topological insulator surface
• Dirac point spectral weight suppression and surface "gaps" in nonmagnetic and magnetic topological insulators

Cited by in corpus (7)

• Signatures of Topological Superconductivity in Bulk Insulating Topological Insulator BiSbTe${}_{1.25}$Se${}_{1.75}$ in Proximity with Superconducting NbSe${}_2$
• Spectromicroscopic measurement of surface and bulk band structure interplay in a disordered topological insulator
• Nature of the Dirac gap modulation and surface magnetic interaction in axion antiferromagnetic topological insulator MnBi${}_2$Te${}_4$
• Doping-controlled surface conduction in topological insulators with warping effects
• Impurity-potential-induced gap at the Dirac point of topological insulators with in-plane magnetization
• Electron scattering in a superlattice of line defects on the surface of topological insulators
• Non-local Chemical Potential Modulation in Topological Insulators Via Electric Field Driven Trapped Charge Migration