Strongly correlated electronic states and dielectric engineering in heterobilayer, heterotrilayer and bilayer-bilayer MoSe<sub>2</sub>/WSe<sub>2</sub> heterostructures

ORAL

Abstract

Moiré heterostructures formed from twisted layers of transition metal dichalcogenides (TMDs) have been shown to host strongly correlated states including Mott insulators and Wigner crystals. However, experimental investigations have been mostly limited to two stacked monolayers. Here we use white light reflection spectroscopy to investigate the intralayer excitons in a unique device of stacked WSe2/MoSe2 where there are 1L/1L, 2L/1L, 1L/2L and 2L/2L regions with the same twist angle (~57 degrees).  Changing the carrier concentration we compare the correlated electron and hole states formed in each region. We observe, relative to the 1L/1L heterobilayer, correlations are suppressed in heterostructures using 2L MoSe2, while they are enhanced using 2L WSe2. Due to different dielectric environments we also observe an energetic splitting of the intralayer excitons localised in seperate layers of the bilayers. In 2L WSe2/1L MoSe2 we probe the effects of the correlated electronic insulating phases on each layer-localised exciton and find larger changes to the peak position and linewidth in the layer adjacent to the heterostructure interface. Our results introduce layer thickness as a new tuning knob for the formation of correlated electronic states in TMD moiré heterostructures. 

*This work was supported by the EPSRC (grant nos. EP/P029892/1 and EP/L015110/1), the ERC (grant no. 725920) and the EU Horizon 2020 research and innovation program (grant agreement no. 820423. The growth of hBN crystals by K.W. and T.T. was supported by the Elemental Strategy Initiative conducted by MEXT, Japan (grant no.JPMXP0112101001), JSPS KAKENHI (grant no. JP20H00354) and CREST (grant no. JMPJCR15F3), JST. B.D.G. is supported by a Wolfson Merit Award from the Royal Society and a Chair in Emerging Technology from the Royal Academy of Engineering.

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Publication: 'Strongly correlated electronic states and dielectric engineering in heterobilayer, heterotrilayer and bilayer-bilayer MoSe2/WSe2 heterostructures', Aidan Campbell, Mauro Brotons-Gisbert, Shun Feng, Hyeonjun Baek, Kenji Watanabe, Takashi Taniguchi, Brian D. Gerardot (Manuscript in preparation)

Presenters

  • Aidan J Campbell

    • Heriot-Watt Univ
    • Heriot-Watt University

Authors

  • Aidan J Campbell

    • Heriot-Watt Univ
    • Heriot-Watt University

  • Mauro Brotons-Gisbert

    • Heriot-Watt Univ
    • Heriot-Watt University

  • Shun Feng

    • Heriot-Watt Univ
    • Heriot-Watt University

  • Hyeonjun Baek

    • Heriot-Watt University

  • 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

  • Brian D Gerardot

    • Heriot-Watt Univ
    • Heriot-Watt University