Bulk contribution to magnetotransport properties of low defect-density Bi${}_2$Te${}_3$ topological insulator thin films

Abstract

An important challenge in the field of topological materials is to carefully disentangle the electronic transport contribution of the topological surface states from that of the bulk. For Bi${}_2$Te${}_3$ topological insulator samples, bulk single crystals and thin films exposed to air during fabrication processes are known to be bulk conducting, with the chemical potential in the bulk conduction band. For Bi${}_2$Te${}_3$ thin films grown by molecular beam epitaxy, we combine structural characterization (transmission electron microscopy), chemical surface analysis as function of time (x-ray photoelectron spectroscopy) and magnetotransport analysis to understand the low defect density and record high bulk electron mobility once charge is doped into the bulk by surface degradation. Carrier densities and electronic mobilities extracted from the Hall effect and the quantum oscillations are consistent and reveal a large bulk carrier mobility. Because of the cylindrical shape of the bulk Fermi surface, the angle dependence of the bulk magnetoresistance oscillations is two-dimensional in nature.

12 pages, 5 figures

References in corpus (16)

• Topological origin of subgap conductance in insulating bilayer graphene
• Two-dimensional Dirac fermions in a topological insulator: transport in the quantum limit
• Coexistence of the topological state and a two-dimensional electron gas on the surface of Bi2Se3
• Observation of topological surface state quantum Hall effect in an intrinsic three-dimensional topological insulator
• Surface State Transport and Ambipolar Electric Field Effect in Bi2Se3 Nanodevices
• Transport Properties of Topological Insulators: Band Bending, Bulk Metal-to-Insulator Transition, and Weak Anti-Localization
• Emergence of decoupled surface transport channels in bulk insulating Bi2Se3 thin films
• Realization of a vertical topological p-n junction in epitaxial $\mathrm{S}{\mathrm{b}}_2\mathrm{T}{\mathrm{e}}_3/B{\mathrm{i}}_2\mathrm{T}{\mathrm{e}}_3$ heterostructures
• Extremely large non-saturating magnetoresistance and ultrahigh mobility due to topological surface states in metallic Bi2Te3 topological insulator
• Magnetotransport and induced superconductivity in Bi based three-dimensional topological insulators
• In-situ spectroscopy of intrinsic Bi2Te3 topological insulator thin films and impact of extrinsic defects
• Shubnikov-de Haas oscillations from topological surface states of metallic Bi${}_2$Se${}_{2.1}$Te${}_{0.9}$
• Protective capping of topological surface states of intrinsically insulating Bi${}_2$Te${}_3$
• Gate-tunable transport properties of in-situ capped Bi${}_2$Te${}_3$ topological insulator thin films
• Role of Se vacancies on Shubnikov de Haas oscillations in Bi2Se3: a combined magneto-resistance and positron annihilation study
• Coexistence of bulk and surface states probed by Shubnikov-de Haas oscillations in Bi${}_2$Se${}_3$ with high charge-carrier density

Cited by in corpus (4)

• Quantum Transport and Potential of Topological States for Thermoelectricity in Bi${}_2$Te${}_3$ Thin Films
• High-temperature-grown buffer layer boosts electron mobility in epitaxial La-doped BaSnO${}_3$/SrZrO${}_3$ heterostructures
• Josephson Effect and Charge Distribution in Thin Bi${}_2$Te${}_3$ Topological Insulators
• Combined Spectroscopy and Electrical Characterization of La:BaSnO${}_{\text{3}}$ Thin Films and Heterostructures