Gate-Variable Mid-Infrared Optical Transitions in a $(B{i}_{1-x}S{b}_x{)}_{2}T{e}_3$ Topological Insulator

Abstract

We report mid-infrared spectroscopy measurements of an electrostatically gated topological insulator, in which we observe several percent modulation of transmittance and reflectance of (Bi1-xSbx)2Te3 films as gating shifts the Fermi level. Infrared transmittance measurements of gated (Bi1-xSbx)2Te3 films were enabled by use of an epitaxial lift-off method for large-area transfer of topological insulator films from infrared-absorbing SrTiO3 growth substrates to thermal oxidized silicon substrates. We combine these optical experiments with transport measurements and angle-resolved photoemission spectroscopy to identify the observed spectral modulation as a gate-driven transfer of spectral weight between both bulk and topological surface channels and interband and intraband channels. We develop a model for the complex permittivity of gated (Bi1-xSbx)2Te3, and find a good match to our experimental data. These results open the path for layered topological insulator materials as a new candidate for tunable infrared optics and highlight the possibility of switching topological optoelectronic phenomena between bulk and spin-polarized surface regimes.

References in corpus (30)

• Topological Insulators
• Topological insulators and superconductors
• Black phosphorus field-effect transistors
• Experimental Observation of the Quantum Anomalous Hall Effect in a Magnetic Topological Insulator
• Graphene plasmonics
• Gate-tuning of graphene plasmons revealed by infrared nano-imaging
• Optical modulators with two-dimensional layered materials
• Optical properties of graphene
• Spintronics and Pseudospintronics in Graphene and Topological Insulators
• Tunable optical properties of multilayers black phosphorus thin films
• Control over topological insulator photocurrents with light polarization
• Gate-Voltage Control of Chemical Potential and Weak Anti-localization in Bismuth Selenide
• Plasmons and screening in monolayer and multilayer black phosphorus
• Band structure engineering in (Bi1-xSbx)2Te3 ternary topological insulators
• First Principles Studies on 3-Dimentional Strong Topological Insulators: Bi2Te3, Bi2Se3 and Sb2Te3
• Observation of Dirac plasmons in a topological insulator
• THz response and colossal Kerr rotation from the surface states of the topological insulator Bi${}_2$Se${}_3$
• Collective modes of a helical liquid
• Multilayer black phosphorus as a versatile mid-infrared electro-optic material
• Ultraviolet and visible range plasmonics of a topological insulator
• Transport Properties of Topological Insulators: Band Bending, Bulk Metal-to-Insulator Transition, and Weak Anti-Localization
• Chiral plasmons without magnetic field
• Topological insulators are tunable waveguides for hyperbolic polaritons
• Terahertz Kerr and Reflectivity Measurements on the Topological Insulator Bi2Se3
• Optical evidence of surface state suppression in Bi based topological insulators
• Hexagonal warping on optical conductivity of surface states in Topological Insulator Bi_{2}Te_{3}
• Electrostatic Coupling between Two Surfaces of a Topological Insulator Nanodevice
• Transferring MBE-grown topological insulator films to arbitrary substrates and Metal-insulator transition via Dirac gap
• Dirac cone shift of a passivated topological Bi2Se3 interface state
• Lighting up topological insulators: large surface photocurrents from magnetic superlattices

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• Controlling helicity-dependent photocurrent in polycrystalline Sb${}_2$Te${}_2$Se topological insulator thin films at ambient temperature through wave-vector of and photothermal gradient due to polarized light
• Topological layered n-type thermoelectrics based on bismuth telluride solid solutions