Field-induced recovery of massless Dirac fermions in epitaxial graphene on SiC

Hyungjun Lee, Seungchul Kim, Jisoon Ihm, Young Woo Son, Hyoung Joon Choi

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

We report first-principles calculations of atomic and electronic structures of epitaxial single-layer graphene on Si-terminated 4H-SiC(0 0 0 1) surface under homogeneous transverse electric fields. We find that atomic positions are insensitive to applied electric fields, but the electronic band structures of the graphene layer are shifted in energy, depending strongly on the applied electric fields, while those of the buffer layer are almost unchanged. This effect finally results in field-induced closing of the energy gap at the Dirac energy point and recovery of the conic feature of the low-energy band structures of free-standing graphene, which are verified and analyzed further with a tight-binding model consisting of the single-layer and the buffer-layer graphene only. The recovery of conical dispersion of the single-layer graphene and ambipolar field-effect behavior, despite the band-gap closure under electric field, makes epitaxial single-layer graphene one of the promising alternatives to current state-of-the-art transistors for radiofrequency applications.

Original languageEnglish
Pages (from-to)2300-2305
Number of pages6
JournalCarbon
Volume49
Issue number7
DOIs
Publication statusPublished - 2011 Jun 1

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Graphite
Fermions
Graphene
Recovery
Electric fields
Band structure
Buffer layers
Energy gap
Crystal atomic structure
Electronic structure
Transistors

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Materials Science(all)

Cite this

Lee, Hyungjun ; Kim, Seungchul ; Ihm, Jisoon ; Son, Young Woo ; Choi, Hyoung Joon. / Field-induced recovery of massless Dirac fermions in epitaxial graphene on SiC. In: Carbon. 2011 ; Vol. 49, No. 7. pp. 2300-2305.
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Field-induced recovery of massless Dirac fermions in epitaxial graphene on SiC. / Lee, Hyungjun; Kim, Seungchul; Ihm, Jisoon; Son, Young Woo; Choi, Hyoung Joon.

In: Carbon, Vol. 49, No. 7, 01.06.2011, p. 2300-2305.

Research output: Contribution to journalArticle

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AB - We report first-principles calculations of atomic and electronic structures of epitaxial single-layer graphene on Si-terminated 4H-SiC(0 0 0 1) surface under homogeneous transverse electric fields. We find that atomic positions are insensitive to applied electric fields, but the electronic band structures of the graphene layer are shifted in energy, depending strongly on the applied electric fields, while those of the buffer layer are almost unchanged. This effect finally results in field-induced closing of the energy gap at the Dirac energy point and recovery of the conic feature of the low-energy band structures of free-standing graphene, which are verified and analyzed further with a tight-binding model consisting of the single-layer and the buffer-layer graphene only. The recovery of conical dispersion of the single-layer graphene and ambipolar field-effect behavior, despite the band-gap closure under electric field, makes epitaxial single-layer graphene one of the promising alternatives to current state-of-the-art transistors for radiofrequency applications.

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