Creation of Helical Dirac Fermions by Interfacing Two Gapped Systems of Ordinary Fermions

Abstract

Topological insulators (TIs) are a unique class of materials characterized by a surface (edge) Dirac cone state of helical Dirac fermions in the middle of bulk (surface) gap. When the thickness (width) of TIs is reduced, however, interaction between the surface (edge) states will open a gap removing the Dirac cone. Using density function theory calculation, we demonstrate the creation of helical Dirac fermions from interfacing two gapped TI films, a single bilayer Bi grown on a single quintuple layer Bi2Se3 or Bi2Te3. The theoretical prediction is directly confirmed by experiment. We further show that the extrinsic helical Dirac fermions consists of predominantly Bi bilayer states, which are created by a giant Rashba effect due to interfacial charge transfer. Our findings provide a promising new method to create novel TI materials by interface engineering.

18 pages and 4 figures

References in corpus (24)

• Topological Insulators
• Quantum Spin Hall Effect in Graphene
• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Topological Insulators in Three Dimensions
• Topological Insulators with Inversion Symmetry
• 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
• Quantum Spin Hall Effect
• First observation of Spin-Momentum Helical Locking in Bi2Se3 and Bi2Te3, demonstration of Topological-Order at 300K and a realization of topological-transport-regime
• Crossover of Three-Dimensional Topological Insulator of Bi2Se3 to the Two-Dimensional Limit
• Giant Spin-splitting in the Bi/Ag(111) Surface Alloy
• Quantum Spin Hall Effect and Enhanced Magnetic Response by Spin-Orbit Coupling
• Electrically detected interferometry of Majorana fermions in a topological insulator
• Spin Polarization and Transport of Surface States in the Topological Insulators Bi2Se3 and Bi2Te3 from First Principles
• Large tuneable Rashba spin splitting of a two-dimensional electron gas in Bi2Se3
• Well-localized edge states in two-dimensional topological insulators: ultrathin Bi films
• Stable nontrivial Z2 topology in ultrathin Bi (111) films: a first-principles study
• Angle Dependent Van Hove Singularities in Slightly Twisted Graphene Bilayer
• Exciton condensation and charge fractionalization in a topological insulator film
• Reactive chemical doping of the $B{i}_{2}S{e}_3$ topological insulator
• Silicon surface with giant spin-splitting
• Rashba spin-splitting control at the surface of the topological insulator Bi2Se3
• Topological insulator Bi2Se3 thin films grown on double-layer graphene by molecular beam epitaxy
• Robustness of topologically protected surface states in layering of Bi2Te3 thin films

Cited by in corpus (25)

• Colloquium: Topological Band Theory
• Emergent Phenomena Induced by Spin-Orbit Coupling at Surfaces and Interfaces
• Organic Topological Insulators in Organometallic Lattices
• Epitaxial growth of large-gap quantum spin Hall insulator on semiconductor surface
• Functionalized Bismuth Films: Giant Gap Quantum Spin Hall and Valley-Polarized Quantum Anomalous Hall States
• Formation of quantum spin Hall state on Si surface and energy gap scaling with strength of spin orbit coupling
• Visualizing topological edge states of single and double bilayer Bi supported on multibilayer Bi(111) films
• Symmetry-enforced ideal lantern-like phonons in ternary nitride Li${}_6$WN${}_4$
• The edge engineering of topological Bi(111) bilayer
• Engineering electronic structure of a 2D topological insulator Bi(111) bilayer on Sb nanofilms by quantum confinement effect
• Functionalized Thallium Antimony Films as Excellent Candidates for Large-Gap Quantum Spin Hall Insulator
• Intra- and Interband Electron Scattering in the Complex Hybrid Topological Insulator Bismuth Bilayer on Bi${}_2$Se${}_3$
• Role played by strain on Plasmons, screening and energy loss in Graphene/substrate contacts
• Orbit- and Atom-Resolved Spin Textures of Intrinsic, Extrinsic and Hybridized Dirac Cone States
• Optical Properties of Monolayer Bismuthene in Electric Fields
• Topological Proximity Effects in Graphene Nanoribbon Heterostructures
• Edge States of α-Bismuthene Nanostructures
• Tailoring Kinetics on a Topological Insulator Surface by Defect-Induced Strain: Pb Mobility on Bi2Te3
• The growth of bismuth on Bi${}_2$Se${}_3$ and the stability of the first bilayer
• Transmission in graphene-topological insulator heterostructures
• Pyridine intercalated Bi${}_2$Se${}_3$ heterostructures: controlling the topologically protected states
• Halogen adsorption and reaction with Bi${}_2$(Se,Te)${}_3$ and Bi/Bi${}_2$(Se,Te)${}_3$
• Tuning Transport Properties of Topological Edge States of Bi(111) Bilayer Film by Edge Adsorption
• Robust large-gap topological insulator phase in transition-metal chalcogenide ZrTe${}_4$Se
• Atomically Abrupt Topological p-n Junction