Topologically Protected Helical States in Minimally Twisted Bilayer Graphene

Shengqiang Huang, Kyounghwan Kim, Dmitry K. Efimkin, Timothy Lovorn, Takashi Taniguchi, Kenji Watanabe, Allan H. Macdonald, Emanuel Tutuc, Brian J Leroy

Research output: Contribution to journalArticle

33 Citations (Scopus)

Abstract

In minimally twisted bilayer graphene, a moiré pattern consisting of AB and BA stacking regions separated by domain walls forms. These domain walls are predicted to support counterpropogating topologically protected helical (TPH) edge states when the AB and BA regions are gapped. We fabricate designer moiré crystals with wavelengths longer than 50 nm and demonstrate the emergence of TPH states on the domain wall network by scanning tunneling spectroscopy measurements. We observe a double-line profile of the TPH states on the domain walls, only occurring when the AB and BA regions are gapped. Our results demonstrate a practical and flexible method for TPH state network construction.

Original languageEnglish (US)
Article number037702
JournalPhysical Review Letters
Volume121
Issue number3
DOIs
StatePublished - Jul 17 2018

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domain wall
graphene
scanning
profiles
wavelengths
spectroscopy
crystals

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Topologically Protected Helical States in Minimally Twisted Bilayer Graphene. / Huang, Shengqiang; Kim, Kyounghwan; Efimkin, Dmitry K.; Lovorn, Timothy; Taniguchi, Takashi; Watanabe, Kenji; Macdonald, Allan H.; Tutuc, Emanuel; Leroy, Brian J.

In: Physical Review Letters, Vol. 121, No. 3, 037702, 17.07.2018.

Research output: Contribution to journalArticle

Huang, S, Kim, K, Efimkin, DK, Lovorn, T, Taniguchi, T, Watanabe, K, Macdonald, AH, Tutuc, E & Leroy, BJ 2018, 'Topologically Protected Helical States in Minimally Twisted Bilayer Graphene', Physical Review Letters, vol. 121, no. 3, 037702. https://doi.org/10.1103/PhysRevLett.121.037702
Huang S, Kim K, Efimkin DK, Lovorn T, Taniguchi T, Watanabe K et al. Topologically Protected Helical States in Minimally Twisted Bilayer Graphene. Physical Review Letters. 2018 Jul 17;121(3). 037702. https://doi.org/10.1103/PhysRevLett.121.037702
Huang, Shengqiang ; Kim, Kyounghwan ; Efimkin, Dmitry K. ; Lovorn, Timothy ; Taniguchi, Takashi ; Watanabe, Kenji ; Macdonald, Allan H. ; Tutuc, Emanuel ; Leroy, Brian J. / Topologically Protected Helical States in Minimally Twisted Bilayer Graphene. In: Physical Review Letters. 2018 ; Vol. 121, No. 3.
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