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

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Graphite
Graphene
valleys
graphene
Gases
insulators
Molecules
gases
molecules
Energy gap
Electric fields
Electric dipole moments
Electrons
Valence bands
Conduction bands
Band structure
electric fields
Density functional theory
Electrostatics
electric moments

Keywords

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

ASJC Scopus subject areas

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

Cite this

Quantum valley Hall state in gas molecule-adsorbed bilayer graphene. / Lee, Kyu Won; Lee, Cheol Eui.

In: Current Applied Physics, Vol. 16, No. 2, 01.02.2016, p. 160-164.

Research output: Contribution to journalArticle

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