Lattice-matched heterojunctions between topological and normal insulators: A first-principles study

Abstract

Gapless boundary modes at the interface between topologically distinct regions are one of the most salient manifestations of topology in physics. Metallic boundary states of time-reversal-invariant topological insulators (TIs), a realization of topological order in condensed matter, have been of much interest not only due to such a fundamental nature, but also due to their practical significance. These boundary states are immune to backscattering and localization owing to their topological origin, thereby opening up the possibility to tailor them for potential uses in spintronics and quantum computing. The heterojunction between a TI and a normal insulator (NI) is a representative playground for exploring such a topologically protected metallic boundary state and expected to constitute a building block for future electronic and spintronic solid-state devices based on TIs. Here, we report a first-principles study of two experimentally realized lattice-matched heterojunctions between TIs and NIs, Bi${}_2$Se${}_3$(0001)/InP(111) and Bi${}_2$Te${}_3$(0001)/BaF${}_2$(111). We evaluate the band offsets at these interfaces from many-body perturbation theory within the $GW$ approximation as well as density-functional theory. Furthermore, we investigate the topological interface states, demonstrating that at these lattice-matched heterointerfaces they are strictly localized and their helical spin textures are as well preserved as those at the vacuum-facing surfaces. These results taken together may help in designing devices relying on spin-helical metallic boundary states of TIs.

arXiv comment9 pages, 7 figures

References in corpus (30)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Topological Insulators
• Topological insulators and superconductors
• Quantum Spin Hall Effect in Graphene
• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• $Z_2$ Topological Order and the Quantum Spin Hall Effect
• A topological Dirac insulator in a quantum spin Hall phase : Experimental observation of first strong topological insulator
• Optimized norm-conserving Vanderbilt pseudopotentials
• First observation of Spin-Momentum Helical Locking in Bi2Se3 and Bi2Te3, demonstration of Topological-Order at 300K and a realization of topological-transport-regime
• First direct observation of Spin-textures in Topological Insulators : Spin-resolved ARPES as a probe of topological quantum spin Hall effect and Berry's phase
• Yambo: an \textit{ab initio} tool for excited state calculations
• Electric Field Control of the LaAlO${}_3$/SrTiO${}_3$ Interface Ground State
• Hexagonal Warping Effects in the Surface States of Topological Insulator Bi${}_2$Te${}_3$
• High-temperature interface superconductivity between metallic and insulating cuprates
• Spin Polarization and Transport of Surface States in the Topological Insulators Bi2Se3 and Bi2Te3 from First Principles
• Spectral and Fermi surface properties from Wannier interpolation
• Rapid Surface Oxidation as a Source of Surface Degradation Factor for Bi2Se3
• Emergent properties hidden in plane view: Strong electronic correlations at oxide interfaces
• Predictive GW calculations using plane waves and pseudopotentials
• Band Offsets at the Si/SiO${}_2$ Interface from Many-Body Perturbation Theory
• Chiral orbital-angular-momentum in the surface states of Bi2Se3
• Quasiparticle Electronic structure of Copper in the GW approximation
• Robustness of topologically protected surface states in layering of Bi2Te3 thin films
• Intrinsic conduction through topological surface states of insulating Bi${}_2$Te${}_3$ epitaxial thin films
• Molecular beam epitaxy of high structural quality Bi2Se3 on lattice matched InP(111) substrates
• Magneto-optics of massive Dirac fermions in bulk Bi2Se3
• Low-velocity anisotropic Dirac fermions on the side surface of topological insulators
• Direct observation of decoupled Dirac states at the interface between topological and normal insulators
• Electric fields and valence band offsets at strained [111] heterojunctions
• Particle Physics and Condensed Matter: The Saga Continues

Cited by in corpus (1)

• Importance of van der Waals interactions for ab initio studies of topological insulators