Spectroscopic signature of surface states and bunching of bulk subbands in topological insulator (Bi${}_{0.4}$Sb${}_{0.6}$)${}_2$Te${}_3$ thin films

Abstract

High quality thin films of the topological insulator (Bi${}_{0.4}$Sb${}_{0.6}$)${}_2$Te${}_3$ have been deposited on SrTiO${}_3$ (111) by molecular beam epitaxy. Their electronic structure was investigated by in situ angle-resolved photoemission spectroscopy and in situ scanning tunneling spectroscopy. The experimental results reveal striking similarities with relativistic ab-initio tight binding calculations. We find that ultrathin slabs of the three-dimensional topological insulator (Bi${}_{0.4}$Sb${}_{0.6}$)${}_2$Te${}_3$ display topological surface states, surface states with large weight on the outermost Te atomic layer, and dispersive bulk energy levels that are quantized. We observe that the bandwidth of the bulk levels is strongly reduced. These bunched bulk states as well as the surface states give rise to strong peaks in the local density of states.

arXiv comment8 pages, 4 figures, 4 pages of supplemental material

References in corpus (15)

• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
• Band structure engineering in (Bi1-xSbx)2Te3 ternary topological insulators
• Oscillatory crossover from two dimensional to three dimensional topological insulators
• Finite size effects of helical edge states in HgTe/CdTe quantum wells
• Anomalous Finite Size Effects on Surface States in the Topological Insulator Bi${}_2$Se${}_3$
• Landau quantization and the thickness limit of topological insulator thin films of Sb2Te3
• Fermi Level Tuning of Epitaxial Sb2Te3 Thin Films on Graphene by Regulating Intrinsic Defects and Substrate Transfer Doping
• Persistence of Topological Order and Formation of Quantum Well States in Topological Insulators Bi2(Se,Te)3 under Ambient Conditions
• Spin-orbit interaction effect in the electronic structure of \BiTe \ observed by angle-resolved photoemission spectroscopy
• In-situ spectroscopy of intrinsic Bi2Te3 topological insulator thin films and impact of extrinsic defects
• Topological phases of topological insulator thin films
• Defect Role in the Carrier Tunable Topological Insulator (Bi${}_{1-x}$Sb${}_x$)${}_2$Te${}_3$ Thin Films
• Visualizing the multifractal wavefunctions of a disordered two-dimensional electron gas

Cited by in corpus (3)

• Growth control of highly textured Bi2Te3 thin films by pulsed laser deposition
• Observation of the surface hybridization gap in the electrical transport properties of the ultrathin topological insulator (Bi${}_{1-x}$Sb${}_x$)${}_2$Te${}_3$
• Entropy Driven Inductive Response of Topological Insulators