Observation of Ultrahigh Mobility Surface States in a Topological Crystalline Insulator by Infrared Spectroscopy

Abstract

Topological crystalline insulators (TCIs) possess metallic surface states protected by crystalline symmetry, which are a versatile platform for exploring topological phenomena and potential applications. However, progress in this field has been hindered by the challenge to probe optical and transport properties of the surface states owing to the presence of bulk carriers. Here we report infrared (IR) reflectance measurements of a TCI, (001) oriented $P{b}_{1-x}S{n}_{x}Se$ in zero and high magnetic fields. We demonstrate that the far-IR conductivity is unexpectedly dominated by the surface states as a result of their unique band structure and the consequent small IR penetration depth. Moreover, our experiments yield a surface mobility of 40000 $c{m}^2/(Vs)$, which is one of the highest reported values in topological materials, suggesting the viability of surface-dominated conduction in thin TCI crystals. These findings pave the way for exploring many exotic transport and optical phenomena and applications predicted for TCIs.

References in corpus (40)

• Topological Insulators
• Topological insulators and superconductors
• Topological Crystalline Insulators
• Crossover of Three-Dimensional Topological Insulator of Bi2Se3 to the Two-Dimensional Limit
• Topological Crystalline Insulators in the SnTe Material Class
• Experimental realization of a topological crystalline insulator in SnTe
• Kramers-Kronig constrained variational analysis of optical spectra
• Magneto-optical conductivity in Graphene
• Topological crystalline insulator states in Pb(1-x)Sn(x)Se
• Electrodynamics of Correlated Electron Materials
• Topological Crystalline Insulators and Topological Superconductors: From Concepts to Materials
• A topological crystalline insulator (TCI) phase via topological phase transition and crystalline mirror symmetry
• Topological origin of subgap conductance in insulating bilayer graphene
• Two-dimensional Dirac fermions in a topological insulator: transport in the quantum limit
• Infrared spectroscopy of Landau levels in graphene
• Observation of topological surface state quantum Hall effect in an intrinsic three-dimensional topological insulator
• Spin-filtered Edge States with an Electrically Tunable Gap in a Two-Dimensional Topological Crystalline Insulator
• Observation of Dirac Holes and Electrons in a Topological Insulator
• Observation of Dirac node formation and mass acquisition in a topological crystalline insulator
• Colloquium: Graphene spectroscopy
• Surface States of Topological Crystalline Insulators in IV-VI Semiconductors
• Strain-induced partially flat band, helical snake states, and interface superconductivity in topological crystalline insulators
• Large Chern Number Quantum Anomalous Hall Effect In Thin-film Topological Crystalline Insulators
• Observation of an intrinsic bandgap and Landau level renormalization in graphene/boron-nitride heterostructures
• Evidence for massive bulk Dirac Fermions in Pb${}_{1-x}$Sn${}_x$Se from Nernst and thermopower experiments
• Magneto-optical conductivity of Weyl semimetals
• Topological Surface Transport in Epitaxial SnTe Thin Films Grown on Bi2Te3
• Dirac mass generation from crystal symmetry breaking on the surfaces of topological crystalline insulators
• Symmetry breaking and Landau quantization in topological crystalline insulators
• Surface state charge dynamics of a high-mobility three dimensional topological insulator
• Quantum Coherent Transport in SnTe Topological Crystalline Insulator Thin Films
• High-Resolution Faraday Rotation and Electron-Phonon Coupling in Surface States of the Bulk-Insulating Topological Insulator Cu${}_{0.02}$Bi${}_2$Se${}_3$
• Optical evidence of surface state suppression in Bi based topological insulators
• Infrared probe of the anomalous magnetotransport of highly oriented pyrolytic graphite in the extreme quantum limit
• Valleytronics on the Surface of Topological Crystalline Insulator: Elliptic Dichroism and Valley-Selective Optical Pumping
• Topological phase diagram and saddle point singularity in a tunable topological crystalline insulator
• Dirac cone shift of a passivated topological Bi2Se3 interface state
• Optical investigation of thermoelectric topological crystalline insulator Pb${}_{0.77}$Sn${}_{0.23}$Se
• Temperature-driven band inversion in Pb${}_{0.77}$Sn${}_{0.23}$Se: Optical and Hall-effect studies
• Measurement of the topological surface state optical conductance in bulk-insulating Sn-doped Bi${}_{1.1}$Sb${}_{0.9}$Te${}_2$S single crystals

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• Chiral Landau levels in Weyl semimetal NbAs with multiple topological carriers
• Giant Photonic Response of Mexican-hat Topological Semiconductors for Mid-infrared to THz Applications
• Tunable Dirac interface states in topological superlattices
• Landau level spectroscopy of PbSnSe topological crystalline insulator
• Weak antilocalization beyond the fully diffusive regime in Pb1-xSnxSe topological quantum wells
• Band structure and topological phases of Pb${}_{1-x-y}$Sn${}_x$Mn${}_y$Te by ab initio calculations
• Evolution of the optical response of the magnetic topological insulators Mn(Bi${}_{1-x}$Sb${}_x$)${}_2$Te${}_4$ with Sb content
• Ge as an orbitronic platform: giant in-plane orbital magneto-electric effect in a 2-dimensional hole gas