Intrinsic Ultrathin Topological Insulators Grown via MBE Characterized by in-situ Angle Resolved Photoemission Spectroscopy

Abstract

We demonstrate the capability of growing high quality ultrathin films of the topological insulators Bi2Se3 and Bi2Te3 using molecular beam epitaxy. Unlike previous growth techniques, which often pin the Fermi energy in the conduction band for ultrathin samples, our samples remain intrinsic bulk insulators. We characterize these films using in-situ angle resolved photoemission spectroscopy (ARPES), which is a direct probe of bandstructure, and ex-situ atomic force microscopy. We find that the conduction band lies above the Fermi energy, indicating bulk insulating behavior with only the surface states crossing EF . We conclude that thermal cracking of Te and Se in our growth leads to higher quality thin films, paving the way for future improvements in growth of topological insulators.

References in corpus (11)

• Topological insulators and superconductors
• Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
• A topological insulator surface under strong Coulomb, magnetic and disorder perturbations
• Band structure engineering in (Bi1-xSbx)2Te3 ternary topological insulators
• Coexistence of the topological state and a two-dimensional electron gas on the surface of Bi2Se3
• Optimizing the Bi_(2-x)Sb_(x)Te_(3-y)Se_(y) solid solutions to approach the intrinsic topological insulator regime
• Electron interaction-driven insulating ground state in Bi2Se3 topological insulators in the two dimensional limit
• Epitaxial growth of topological insulator Bi2Se3 film on Si(111) with atomically sharp interface
• Persistence of Topological Order and Formation of Quantum Well States in Topological Insulators Bi2(Se,Te)3 under Ambient Conditions
• Robust surface electronic properties of topological insulators: Bi2Te3 films grown by molecular beam epitaxy
• Growth of quantum well films of topological insulator Bi2Se3 on insulating substrate

Cited by in corpus (9)

• Direct Optical Coupling to an Unoccupied Dirac Surface State in the Topological Insulator Bi${}_2$Se${}_3$
• Topological Surface Transport in Epitaxial SnTe Thin Films Grown on Bi2Te3
• Dimensional Crossover Induced Topological Hall Effect in a Magnetic Topological Insulator
• Growth, characterization, and transport properties of ternary (Bi1-xSbx)2Te3 topological insulator layers
• How many-body effects modify the van der Waals interaction between graphene sheets
• Monolayer superconductivity and tunable topological electronic structure at the Fe(Te,Se)/Bi2Te3 interface
• Magnetic Order in 3D Topological Insulators -- Wishful Thinking or Gateway to Emergent Quantum Effects?
• Van der Waals Epitaxy on Freestanding Monolayer Graphene Membrane by MBE
• Self-regulated growth of candidate topological superconducting parkerite by molecular beam epitaxy