Quantum valley Hall state in gas molecule-adsorbed bilayer graphene

Kyu Won Lee, Cheol Eui Lee

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

While a variety of topologically nontrivial insulator phases have been predicted to arise from electron-electron and spin-orbit interactions in bilayer graphene, the trigonal warping of conduction and valence bands leads to a (semi)metallic band structure. An electrostatic potential difference between the two layers due to an external electric field is known to open a bandgap, leading to a topologically nontrivial insulator state. A bandgap may also arise from gas molecules adsorbed on bilayer graphene, implying a topologically nontrivial insulator phase. Here, our density functional theory calculations show that bilayer graphene adsorbing gas molecules is a quantum valley Hall insulator. Thus, adsorption of weak donor (or acceptor) molecules with a large electric dipole moment may be instrumental to realize a topologically nontrivial insulator phase in bilayer graphene even without external electric field.

Original languageEnglish
Pages (from-to)160-164
Number of pages5
JournalCurrent Applied Physics
Volume16
Issue number2
DOIs
Publication statusPublished - 2016 Feb 1

Keywords

  • Bilayer graphene
  • Density functional theory
  • Gas molecule adsorption
  • Quantum valley Hall state

ASJC Scopus subject areas

  • Materials Science(all)
  • Physics and Astronomy(all)

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