Positron surface state as a spectroscopic probe for characterizing surfaces of topological insulator materials

Research output: Contribution to journalArticleScientificpeer-review

Researchers

  • Vincent Callewaert
  • K. Shastry
  • Rolando Saniz
  • Ilja Makkonen
  • Bernardo Barbiellini
  • Badih A. Assaf
  • Donald Heiman
  • Jagadeesh S. Moodera
  • Bart Partoens
  • Arun Bansil
  • A. H. Weiss

Research units

Abstract

Topological insulators are attracting considerable interest due to their potential for technological applications and as platforms for exploring wide-ranging fundamental science questions. In order to exploit, fine-tune, control, and manipulate the topological surface states, spectroscopic tools which can effectively probe their properties are of key importance. Here, we demonstrate that positrons provide a sensitive probe for topological states and that the associated annihilation spectrum provides a technique for characterizing these states. Firm experimental evidence for the existence of a positron surface state near Bi2Te2Se with a binding energy of Eb=2.7±0.2eV is presented and is confirmed by first-principles calculations. Additionally, the simulations predict a significant signal originating from annihilation with the topological surface states and show the feasibility to detect their spin texture through the use of spin-polarized positron beams.

Details

Original languageEnglish
Article number115411
JournalPhysical Review B
Volume94
Issue number11
Publication statusPublished - 6 Sep 2016
MoE publication typeA1 Journal article-refereed

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