Thickness-dependent Dirac dispersions of few-layer topological insulators supported by metal substrate

Jeong Heum Jeon, Howon Kim, Won Jun Jang, Jungpil Seo, Se-Jong Kahng

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1 Citation (Scopus)

Abstract

The surface states protected by time-reversal symmetry in 3-dimensional topological insulators have recently been confirmed by angle-resolved photoemission spectroscopy, scanning tunneling microscopy, quantum transport and so on. However, the electronic properties of ultra-thin topological insulator films have not been extensively studied, especially when the films are grown on metal substrates. In this paper, we have elucidated the local behaviors of the electronic states of ultra-thin topological insulator Bi2Se3 grown with molecular beam epitaxy on Au(111) using scanning tunneling microscopy/spectroscopy. We have observed linear dispersion of electron interference patterns at higher energies than the Fermi energy that were not accessible by conventional angle-resolved photoemission spectroscopy. Moreover, the dispersion of the interference patterns varies with the film thickness, which is explained by band bending near the interface between the topological insulator and the metal substrate. Our experiments demonstrate that interfacial effects in thin topological insulator films on metal substrate can be sensed using scanning tunneling spectroscopy.

Original languageEnglish
Article number215207
JournalNanotechnology
Volume28
Issue number21
DOIs
Publication statusPublished - 2017 May 5

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Keywords

  • bismuth selenide
  • Dirac material
  • interface
  • molecular beam epitaxy
  • scanning tunneling microscopy
  • thin topological insulator

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering
  • Electrical and Electronic Engineering

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