Gate-tunable transport properties of in-situ capped Bi${}_2$Te${}_3$ topological insulator thin films

Abstract

Combining the ability to prepare high-quality, intrinsic Bi${}_2$Te${}_3$ topological insulator thin films of low carrier density with in-situ protective capping, we demonstrate a pronounced, gate-tunable change in transport properties of Bi${}_2$Te${}_3$ thin films. Using a back-gate, the carrier density is tuned by a factor of $\sim 7$ in Al${}_2$O${}_3$ capped Bi${}_2$Te${}_3$ sample and by a factor of $\sim 2$ in Te capped Bi${}_2$Te${}_3$ films. We achieve full depletion of bulk carriers, which allows us to access the topological transport regime dominated by surface state conduction. When the Fermi level is placed in the bulk band gap, we observe the presence of two coherent conduction channels associated with the two decoupled surfaces. Our magnetotransport results show that the combination of capping layers and electrostatic tuning of the Fermi level provide a technological platform to investigate the topological properties of surface states in transport experiments and pave the way towards the implementation of a variety of topological quantum devices.

arXiv comment10 pages, 4 figures and 1 table

References in corpus (30)

• $Z_2$ Topological Order and the Quantum Spin Hall Effect
• Topological Insulators in Three Dimensions
• First observation of Spin-Momentum Helical Locking in Bi2Se3 and Bi2Te3, demonstration of Topological-Order at 300K and a realization of topological-transport-regime
• Gate-Voltage Control of Chemical Potential and Weak Anti-localization in Bismuth Selenide
• STM imaging of electronic waves on the surface of Bi${}_2$Te${}_3$: topologically protected surface states and hexagonal warping effects
• Impurity effect on weak anti-localization in the topological insulator Bi2Te3
• $4\pi$-periodic Josephson supercurrent in HgTe-based topological Josephson junctions
• Electrically tunable surface-to-bulk coherent coupling in topological insulator thin films
• Thickness-dependent bulk properties and weak anti-localization effect in topological insulator Bi2Se3
• Evidence for electron-electron interaction in topological insulator thin films
• Tunable Surface Conductivity in Bi2Se3 Revealed in Diffusive Electron Transport
• Ultra-low carrier concentration and surface dominant transport in Sb-doped Bi2Se3 topological insulator nanoribbons
• Weak localization of bulk channels in topological insulator thin film
• Photoelectron spin-flipping and texture manipulation in a topological insulator
• Weak Localization and Antilocalization in Topological Insulator Thin Films with Coherent Bulk-Surface Coupling
• Transport Properties of Topological Insulators: Band Bending, Bulk Metal-to-Insulator Transition, and Weak Anti-Localization
• Weak antilocalization in topological insulator Bi${}_2$Te${}_3$ microflakes
• Coherent Topological Transport on the Surface of Bi2Se3
• Finite-temperature conductivity and magnetoconductivity of topological insulators
• Emergence of decoupled surface transport channels in bulk insulating Bi2Se3 thin films
• Intrinsic conduction through topological surface states of insulating Bi${}_2$Te${}_3$ epitaxial thin films
• Gate-tuned Differentiation of Surface-conducting States in Bi1.5Sb0.5Te1.7Se1.3 Topological-insulator Thin Crystals
• In-situ spectroscopy of intrinsic Bi2Te3 topological insulator thin films and impact of extrinsic defects
• Protective capping of topological surface states of intrinsically insulating Bi${}_2$Te${}_3$
• Experimental evidence and control of the bulk-mediated intersurface coupling in topological insulator Bi2Te2Se nanoribbons
• Top gating of epitaxial (Bi_{1-x}Sb_x)2Te3 topological insulator thin films
• Dynamical Gate Tunable Supercurrents in Topological Josephson Junctions
• Atomic-Layer-Deposited Al2O3 on Bi2Te3 for Topological Insulator Field-Effect Transistors
• Dirac cone shift of a passivated topological Bi2Se3 interface state
• Giant plateau in the THz Faraday angle in gated Bi2Se3

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• Josephson Effect and Charge Distribution in Thin Bi${}_2$Te${}_3$ Topological Insulators
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• Quantum Transport in Air-stable Na3Bi Thin Films
• Combined Spectroscopy and Electrical Characterization of La:BaSnO${}_{\text{3}}$ Thin Films and Heterostructures
• From classical to quantum regime of topological surface states via defect engineering
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