Band Structure of Topological Insulator BiSbTe1.25Se1.75

Abstract

We present our angle resolved photoelectron spectroscopy (ARPES) and density functional theory results on quaternary topological insulator (TI) BiSbTe1.25Se1.75 (BSTS) confirming the non-trivial topology of the surface state bands (SSBs) in this compound. We find that the SSBs, which are are sensitive to the atomic composition of the terminating surface have a partial 3D character. Our detailed study of the band bending (BB) effects shows that in BSTS the Dirac point (DP) shifts by more than two times compared to that in Bi2Se3 to reach the saturation. The stronger BB in BSTS could be due to the difference in screening of the surface charges. From momentum density curves (MDCs) of the ARPES data we obtained an energy dispersion relation showing the warping strength of the Fermi surface in BSTS to be intermediate between those found in Bi2Se3 and Bi2Te3 and also to be tunable by controlling the ratio of chalcogen/pnictogen atoms. Our experiments also reveal that the nature of the BB effects are highly sensitive to the exposure of the fresh surface to various gas species. These findings have important implications in the tuning of DP in TIs for technological applications.

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• Topological Insulators
• Topological insulators and superconductors
• Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
• Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
• First observation of Spin-Momentum Helical Locking in Bi2Se3 and Bi2Te3, demonstration of Topological-Order at 300K and a realization of topological-transport-regime
• First direct observation of Spin-textures in Topological Insulators : Spin-resolved ARPES as a probe of topological quantum spin Hall effect and Berry's phase
• Seeing the magnetic monopole through the mirror of topological surface states
• Hexagonal Warping Effects in the Surface States of Topological Insulator Bi${}_2$Te${}_3$
• Large bulk resistivity and surface quantum oscillations in the topological insulator Bi2Te2Se
• Electrically detected interferometry of Majorana fermions in a topological insulator
• Probing Neutral Majorana Fermion Edge Modes with Charge Transport
• Coexistence of the topological state and a two-dimensional electron gas on the surface of Bi2Se3
• Large tuneable Rashba spin splitting of a two-dimensional electron gas in Bi2Se3
• Observation of topological surface state quantum Hall effect in an intrinsic three-dimensional topological insulator
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• Reactive chemical doping of the $B{i}_{2}S{e}_3$ topological insulator
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• Rashba spin-splitting control at the surface of the topological insulator Bi2Se3
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• Strong potential impurities on the surface of a topological insulator
• Relationship between Fermi-Surface Warping and Out-of-Plane Spin Polarization in Topological Insulators: a View from Spin-Resolved ARPES
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• Dirac states with knobs on: interplay of external parameters and the surface electronic properties of 3D topological insulators
• Band bending at the surface of Bi${}_2$Se${}_3$ studied from first principles

Cited by in corpus (7)

• Signatures of Topological Superconductivity in Bulk Insulating Topological Insulator BiSbTe${}_{1.25}$Se${}_{1.75}$ in Proximity with Superconducting NbSe${}_2$
• Spatially varying electronic dephasing in three dimensional topological insulators
• Gate field effects on the topological insulator BiSbTeSe2 interface
• The anomalous spin texture as the probe for interactions in $B{i}_{2-y}S{b}_{y}S{e}_{x}T{e}_{3-x}$
• Observation of Dirac-like surface state bands on the top surface of BiSe
• Conductance Oscillations in a Topological Insulator-Disordered Superconductor Hybrid Interface
• Vapor phase growth and characterization of van der Waals BiSbTeSe platelets on semiconducting MoS2