Theoretical study ofChern transitions in Hofstadter bands of twisted double bilayer graphene

ORAL

Abstract

We study Hofstadter physics of twisted double bilayer graphene (TDBG) in presence of an out-of-plane electric field. In this system Hofstadter bands have unequal distribution of charges in the layers. Moreover, such layer polarization depends on the valley index. These together lead to non-trivial changes of Chern number as a function of the applied electric field. In addition, if we include an assumed spin-exchange, the resulting cascade of even and odd change of Chern numbers matches with the experimental findings. This talk will focus on the theoretical analysis of the work, where the experimental results will be presented in a separate talk.

*D.K.M. would like to acknowledge financial support from Agence Nationale de la Recherche (ANR project "Dirac3D") under Grant No. ANR-17-CE30-0023. D.K.M. and H.A.F. acknowledge support from NSF Grant No. DMR-1914451 and the Research Corporation for Science Advancement through a Cottrell SEED award. H.A.F. further acknowledge the support of NSF Grant No. ECCS-1936406, and of the US-Israel Binational Science Foundation (Grant Nos. 2016130 and 2018726). A.K. acknowledges support from the SERB (Govt. of India) via sanction no. ECR/2018/001443, DAE (Govt. of India ) via sanction no. 58/20/15/2019-BRNS, as well as MHRD (Govt. of India) via sanction no. SPARC/2018-2019/P538/SL.

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Presenters

  • Dibya K Murkehjee

    • Department of Physics, Indiana University, Bloomington, IN 47405
    • Indiana University Bloomington
    • LPS Orsay, Université Paris-Saclay / Indiana University

Authors

  • Dibya K Murkehjee

    • Department of Physics, Indiana University, Bloomington, IN 47405
    • Indiana University Bloomington
    • LPS Orsay, Université Paris-Saclay / Indiana University

  • Pratap C Adak

    • Tata Institute of Fundamental Research, Mumbai
    • Tata Institute of Fundamental Research (

  • Subhajit Sinha

    • Tata Institute of Fundamental Research (

  • DEBASMITA GIRI

    • Indian Institute of Technology Kanpur (I

  • L. D. Varma V Sangani

    • Tata Institute of Fundamental Research, Mumbai
    • Tata Institute of Fundamental Research (TIFR)

  • Kenji Watanabe

    • National Institute for Materials Science, Tsukuba, Japan
    • National Institute for Materials Science
    • NIMS
    • Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan
    • Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan.
    • Research Center for Functional Materials, National Institute for Materials Science
    • Advanced, Materials Laboratory, NIMS
    • 3 National Institute for Materials Science, Tsukuba, Japan
    • National Institute for Materials Science; 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
    • National Institute of Materials Science, Tsukuba, Japan
    • National Institute of Materials Science
    • Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
    • National Institute for Materials Science (Japan)
    • National Institute for Materials Science, Japan
    • Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • Research Center for Functional Materials
    • Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan
    • Research Center for Functional Materials, National Institute for Materials Science, Japan
    • Research Center for Functional Materials, National Institute for Materials Science, 1-1Namiki, Tsukuba 305-0044, Japan
    • National Institute for Material Science, Japan
    • National Institute for Material Science
    • National Institute of Material Sciences, Japan
    • NIMS, Tsukuba
    • 2National Institute for Materials Science, Namiki 1-1, Ibaraki 305-0044, Japan.
    • National Institute of Materials Science, Tsukuba, Ibaraki 305-0044, Japan
    • National Institute for Materials Science Japan
    • NIMS, Japan
    • nims
    • National Institute for Materials Science, Research Center for Functional Materials, Japan
    • National Institute for Materials Science Tsukuba
    • National Institute for Materials Science, 1-1 Namiki
    • National Institute for Materials Science of Japan
    • National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • NIMS - National Institute for Material Science, Japan
    • Research Center for Functional Materials, National Institute for Material Science, Tsukuba, Ibaraki, 305-0044, Japan.
    • National Institute for Material Science, Tsukuba
    • National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan
    • National Institute for Materials Science (NIMS)
    • National Institute for Materials Science, Research Center for Functional Materials
    • Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
    • National Institute of Material Science
    • Kyoto Univ
    • National Institute for Materials Science,1-1 Namiki, Tsukuba, 305-0044, Japan

  • Takashi Taniguchi

    • National Institute for Materials Science, Tsukuba, Japan
    • National Institute for Materials Science
    • NIMS
    • Kyoto Univ
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Ibaraki 305-0044, Japan.
    • 3 National Institute for Materials Science, Tsukuba, Japan
    • National Institute for Materials Science; 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
    • National Institute of Materials Science, Tsukuba, Japan
    • National Institute of Materials Science
    • Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
    • National Institute for Materials Science (Japan)
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • Kyoto University
    • International Center for Materials Nanoarchitectonics
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Japan
    • International Center for Materials Nanoarchitectonics, National Institute for MaterialsScience, 1-1 Namiki, Tsukuba 305-0044, Japan
    • National Institute for Material Science, Japan
    • National Institute for Material Science
    • National Institute of Material Sciences, Japan
    • NIMS, Tsukuba
    • 2National Institute for Materials Science, Namiki 1-1, Ibaraki 305-0044, Japan.
    • National Institute of Materials Science, Tsukuba, Ibaraki 305-0044, Japan
    • National Institute for Materials Science, Japan
    • International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, 1-1 Namiki Tsukuba, Ibaraki 305-0044, Japan.
    • NIMS, Japan
    • National Institute for Materials Science (NIMS)
    • NIMS. Japan
    • International Center for Material Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
    • International Center for Material Nanoarchitectonics, National Institute for Materials Science
    • National Institute for Materials Science Tsukuba
    • National Institute for Materials Science, 1-1 Namiki
    • National Institute for Materials Science of Japan
    • National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • NIMS - National Institute for Material Science, Japan
    • International Center for Materials Nanoarchitectonics, National Institute for Material Science, Tsukuba, Ibaraki 305-0044, Japan.
    • National Institute for Material Science, Tsukuba
    • National Institute for Materials Science, International Center for Materials Nanoarchitectonics
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
    • National Institute of Material Science
    • National Institute for Materials Science,1-1 Namiki, Tsukuba, 305-0044, Japan

  • Herb Fertig

    • Indiana Univ - Bloomington
    • Indiana University Bloomington

  • Arijit Kundu

    • Indian Inst of Tech-Kanpur
    • Indian Instiute of Technology Kanpur

  • Mandar M Deshmukh

    • Tata Institute of Fundamental Research, Mumbai
    • Tata Inst of Fundamental Res
    • Tata Institute of Fundamental Research