Observation of spin-momentum locked surface states in amorphous Bi${}_2$Se${}_3$

Abstract

Crystalline symmetries have played a central role in the identification of topological materials. The use of symmetry indicators and band representations have enabled a classification scheme for crystalline topological materials, leading to large scale topological materials discovery. In this work we address whether amorphous topological materials, which lie beyond this classification due to the lack of long-range structural order, exist in the solid state. We study amorphous Bi${}_2$Se${}_3$ thin films, which show a metallic behavior and an increased bulk resistance. The observed low field magnetoresistance due to weak antilocalization demonstrates a significant number of two dimensional surface conduction channels. Our angle-resolved photoemission spectroscopy data is consistent with a dispersive two-dimensional surface state that crosses the bulk gap. Spin resolved photoemission spectroscopy shows this state has an anti-symmetric spin texture resembling that of the surface state of crystalline Bi${}_2$Se${}_3$. These experimental results are consistent with theoretical photoemission spectra obtained with an amorphous tight-binding model that utilizes a realistic amorphous structure. This discovery of amorphous materials with topological properties uncovers an overlooked subset of topological matter outside the current classification scheme, enabling a new route to discover materials that can enhance the development of scalable topological devices.

arXiv comment30 pages, 4 figures

References in corpus (32)

• Topological Insulators
• The (High Quality) Topological Materials In The World
• The Kernel Polynomial Method
• Weak localisation magnetoresistance and valley symmetry in graphene
• Gate-Voltage Control of Chemical Potential and Weak Anti-localization in Bismuth Selenide
• Topological origin of subgap conductance in insulating bilayer graphene
• Two-dimensional Dirac fermions in a topological insulator: transport in the quantum limit
• Coexistence of the topological state and a two-dimensional electron gas on the surface of Bi2Se3
• Saturation of electrical resistivity
• Observation of topological surface state quantum Hall effect in an intrinsic three-dimensional topological insulator
• Electrically tunable surface-to-bulk coherent coupling in topological insulator thin films
• Optimizing the Bi_(2-x)Sb_(x)Te_(3-y)Se_(y) solid solutions to approach the intrinsic topological insulator regime
• Amorphous topological insulators constructed from random point sets
• Thickness-dependent bulk properties and weak anti-localization effect in topological insulator Bi2Se3
• Structure and Topology of Band Structures in the 1651 Magnetic Space Groups
• Topological Insulators in Random Lattices
• Photoelectron spin-flipping and texture manipulation in a topological insulator
• Transport Properties of Topological Insulators: Band Bending, Bulk Metal-to-Insulator Transition, and Weak Anti-Localization
• Topological phases without crystalline counterparts
• Coherent Topological Transport on the Surface of Bi2Se3
• Emergence of decoupled surface transport channels in bulk insulating Bi2Se3 thin films
• Spin-Polarized Surface Resonances Accompanying Topological Surface State Formation
• Topological Weaire-Thorpe models of amorphous matter
• A high-efficiency spin-resolved phototemission spectrometer combining time-of-flight spectroscopy with exchange-scattering polarimetry
• High Resolution Angle Resolved Photoemission with Tabletop 11eV Laser
• Robust surface electronic properties of topological insulators: Bi2Te3 films grown by molecular beam epitaxy
• Enhanced electron dephasing in three-dimensional topological insulators
• Computation of topological phase diagram of disordered Pb${}_{1-x}$Sn${}_x$Te using the kernel polynomial method
• Amorphous topological phases protected by continuous rotation symmetry
• Disorder-driven topological phase transition in Bi2Se3 films
• Pseudogap in a crystalline insulator doped by disordered metals
• Spin memory of the topological material under strong disorder

Cited by in corpus (29)

• Amorphous topological matter: theory and experiment
• Higher-order topological phases in crystalline and non-crystalline systems: a review
• Surface conduction and reduced electrical resistivity in ultrathin noncrystalline NbP semimetal
• Noncrystalline topological superconductors
• An Exact Chiral Amorphous Spin Liquid
• Topological Anderson amorphous insulator
• Average Symmetry Protected Higher-order Topological Amorphous Insulators
• Physical properties of an Aperiodic monotile: Graphene-like features, chirality and zero-modes
• Local Chern Marker for Periodic Systems
• Embracing Disorder in Quantum Materials Design
• Carrier doping of Bi${}_2$Se${}_3$ surface by chemical adsorption -- a DFT study
• Structural spillage: an efficient method to identify non-crystalline topological materials
• Theory of local ${\mathbb{Z}}_2$ topological markers for finite and periodic two-dimensional systems
• Topological diffusive metal in amorphous transition metal monosilicides
• Amorphous quantum magnets in a two-dimensional Rydberg atom array
• Establishing Coherent Momentum-Space Electronic States in Locally Ordered Materials
• Thin film growth of the Weyl semimetal NbAs
• Electronic rotons and Wigner crystallites in a two-dimensional dipole liquid
• Structure-driven phase transitions in paracrystalline topological insulators
• Topological zero-modes of the spectral localizer of trivial metals
• Quantum Hall criticality in an amorphous Chern insulator
• Family of Aperiodic Tilings with Tunable Quantum Geometric Tensor
• Fluctuations and Correlations of Local Topological Order Parameters in Disordered Two-dimensional Topological Insulators
• Three-Dimensional Quantum Hall Effect in Topological Amorphous Metals
• Disorder-driven exceptional points and concurrent topological phase transitions in non-Hermitian systems
• Aharanov-Bohm oscillations and perfectly transmitted mode in amorphous topological insulator nanowires
• Laser-induced topological phases in monolayer amorphous carbon
• Isotropic 3D topological phases with broken time reversal symmetry
• Coarse geometric approach to topological phases: Invariants from real-space representations