Exciton condensation and charge fractionalization in a topological insulator film

Abstract

An odd number of gapless Dirac fermions is guaranteed to exist at a surface of a strong topological insulator. We show that in a thin-film geometry and under external bias, electron-hole pairs that reside in these surface states can condense to form a coherent exciton condensate, similar in general terms to the exciton condensate recently argued to exist in a biased graphene bilayer, but with different topological properties. Such a `topological' exciton condensate (TEC) exhibits a host of unusual properties; the most interesting among them is the fractional charge +-e/2 carried by a singly quantized vortex in the TEC order parameter.

4 pages, 1 figure, version to appear in PRL (minor stylistic changes). For related work and info visit http://www.physics.ubc.ca/~franz/

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Cited by in corpus (63)

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• Bulk Band Gap and Surface State Conduction Observed in Voltage-Tuned Crystals of the Topological Insulator Bi${}_2$Se${}_3$
• Topological Insulators on the Lieb and Perovskite Lattices
• Tunable Surface Conductivity in Bi2Se3 Revealed in Diffusive Electron Transport
• Simplified topological invariants for interacting insulators
• Topological invariants of Floquet systems: General formulation, special properties, and Floquet topological defects
• Topological Polaritons and Excitons in Garden Variety Systems
• Ultra-thin Topological Insulator Bi2Se3 Nanoribbons Exfoliated by Atomic Force Microscopy
• Quantum oscillations and Berry's phase in topological insulator surface states with broken particle-hole symmetry
• Cooper pairing of electrons and holes in graphene bilayer: Correlation effects
• Creation of Helical Dirac Fermions by Interfacing Two Gapped Systems of Ordinary Fermions
• Interaction-Enhanced Coherence Between Two-Dimensional Dirac Layers
• Strongly Correlated Topological Superconductors and Topological Phase Transitions via Green's Function
• Fractional Fermions with Non-Abelian Statistics
• CaFeAs${}_2$: a Staggered Intercalation of Quantum Spin Hall and High Temperature Superconductivity
• Spatially-indirect Exciton Condensate Phases in Double Bilayer Graphene
• Electrostatic Coupling between Two Surfaces of a Topological Insulator Nanodevice
• Weak Localization and Antilocalization in Topological Materials with Impurity Spin-Orbit Interactions
• Off-resonant polarized light-controlled thermoelectric transport in ultrathin topological insulators
• Spin-polarized tunneling current through a thin film of topological insulator in a parallel magnetic field
• An isolated Dirac cone on the surface of ternary tetradymite-like topological insulators
• Electron-Hole Liquids in Transition Metal Oxide Heterostructures
• Faraday rotation due to surface states in the topological insulator (Bi${}_{1-x}$Sb${}_x$)${}_2$Te${}_3$
• Exciton topology and condensation in a model quantum spin Hall insulator
• Observation of room temperature excitons in an atomically thin topological insulator
• Majorana edge modes of topological exciton condensate with superconductors
• Roton-maxon spectrum and instability for weakly interacting dipolar excitons in a semiconductor layer
• Simultaneous electrical-field-effect modulation of both top and bottom Dirac surface states of epitaxial thin films of three-dimensional topological insulators
• Optical Conductivity of Topological Insulator Thin Films in a Quantizing Magnetic Field
• Spin transport in a unitary Fermi gas close to the BCS transition
• Chiral Topological Excitons in a Chern Band Insulator
• Non-Abelian braiding in spin superconductors utilizing the Aharonov-Casher effect
• Density Waves Instability and a Skyrmion Lattice on the Surface of Strong Topological Insulators
• Photoemission spectra of massless Dirac fermions on the verge of exciton condensation
• Conserved charges of order-parameter textures in Dirac systems
• Nonlocal Andreev reflection, fractional charge and current-phase relation in topological bilayer exciton condensate junctions
• Influence of topological excitations on Shapiro steps and microwave dynamical conductance in bilayer exciton condensates
• Holographic D3-probe-D5 Model of a Double Layer Dirac Semimetal
• How Do You Want That Insulator?
• Zero modes of the generalized fermion-vortex system in magnetic field
• Thermal Transport Properties of Magnons on the $\alpha$-T${}_3$ Lattice
• Measuring the Chern number with quantum oscillations
• Prediction of the quantization of magnetic flux in double layer exciton superfluids
• Fractionalized Metals and Superconductors in Three Dimensions
• Quantum Hall effects of exciton condensate in topological flat bands
• Electrified magnetic catalysis in three-dimensional topological insulators
• Electron dynamics in topological insulator based semiconductor-metal interfaces (topological p-n interface based on Bi2Se3 class)
• Highly tunable optics across a topological transition in organic polymers
• Bilinear planar Hall effect in topological insulators due to spin-momentum locking inhomogeneity
• Intrinsic (Axion) Statistical Topological Insulator
• Strong enhancement of third harmonic generation in a double layer graphene system caused by electron-hole pairing
• First observation of spin-helical Dirac fermions and topological phases in undoped and doped Bi2Te3 demonstrated by spin-ARPES spectroscopy
• Interface engineering of van der Waals heterostructures towards energy-efficient quantum devices operating at high temperatures
• Quasiparticle picture of topological phase transitions induced by interactions
• Chiral universality class of the normal-superconducting and the exciton condensation transition on the surface of topological insulator
• Excitonic gap generation in thin-film topological insulators
• Topological hybrid electron-hole Cooper pairing
• Hybridization and Field Driven Phase Transitions in Hexagonally Warped Topological Insulators
• Fractional spin Josephson effect in topological spin superconductors
• Topological layered n-type thermoelectrics based on bismuth telluride solid solutions