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Independent Superconductors and Correlated Insulators in Twisted Bilayer Graphene

ORAL

Abstract

Twisted bilayer graphene (tBLG) is a moiré heterostructure containing two sheets of graphene stacked on top of each other. At twist angle of θ ≈ 1.1°, theory predicts the formation of a nearly-flat electronic band in tBLG and experiments have successfully shown correlated insulating and superconducting states when the flat band is partially filled. The proximity of superconductivity to correlated insulators suggested a close relationship between these states. In this talk, I will describe our “cut-and-stack” technique to fabricate highly homogeneous tBLG devices, and survey our transport measurements of the intrinsic properties of these devices with a focus on superconductivity. Through transport measurements from five tBLG devices, we show that superconductivity can appear even in the absence of correlated insulating states. Although both superconductivity and correlated insulating behavior are strongest near the flat-band condition, superconductivity survives to larger detuning of the angle.

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Presenters

  • Jingyuan Ge

    University of California, Santa Barbara

Authors

  • Jingyuan Ge

    University of California, Santa Barbara

  • Yu Saito

    University of California, Santa Barbara, University of California at Santa Barbara

  • Takashi Taniguchi

    National Institute for Materials Science, National Institute for Materials Science, Japan, National Institure for Materials Science, Advanced Materials Laboratory, National Institute for Materials Science, NIMS, National Institute of Materials Science, National Institute for Materials Science (NIMS), International Center for Materials Nanoarchitectonics, National Institute for Materials Science, National Institute for Materials Science,1-1 Namiki, National Institute of Material Science, National Institute for Materials Science, Tsukuba, Japan, International Center for Materials Nanoarchitectonics, NIMS, Research Center for Functional Materials, National Institute for Materials Science, National Institute of Materials Science, Tsukuba, Japan, National Institude for Materials Science, International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba 305-0044, Japan, International Center for Materials Nanoarchitectonics, National Institute for Materials, NIMS - Japan, National Institute for Materials Science ,Japan, National Institute for Materials Science, Tsukuba, 305-0044, Ibaraki, Japan, National Institute for Material Science, National Institute for Material Science, 1-1 Namiki, Tsukuba 305-0044, Japan, National Institute for Material Science Japan, 8International Center for Materials Nanoarchitectonics, NIMS Tsukuba, National Institute for Materials Science: Namiki, Tsukuba, Ibaraki, JP, National Institue for Material Science, National Institute for Materials Science,1-1 Namiki, Tsukuba, 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 In, Research Center for Functional Materials, Japan, Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan, International Center for Material Nanoarchitectonics, National Institute for Materials Science, International Center for Materials Nanoarchitectonics, NIMS Suguba, NIMS, Tsukuba, Japan, National Cheng Kung University, National Institute for Materials Science, Namiki 1-1, Tsukuba, 305-0044, Ibaraki, Japan, National institute of material science, Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan, Advanced Materials Laboratory, NIMS, National Institute for Materials Science, International Center for Materials Nanoarchitectonics, National Institute of Material Science, Japan, Tsukuba, National Institute for Materials Science

  • Kenji Watanabe

    National Institute for Materials Science, National Institute for Materials Science, Japan, National Institure for Materials Science, Advanced Materials Laboratory, National Institute for Materials Science, NIMS, National Institute of Materials Science, National Institute for Materials Science (NIMS), Research Center for Functional Materials, National Institute for Materials Science, National Institute for Materials Science,1-1 Namiki, National Institute of Material Science, National Institute for Materials Science, Tsukuba, Japan, Research Center for Functional Materials, NIMS, National Institute of Materials Science, Tsukuba, Japan, National Institude for Materials Science, National Institute for Materials Science, Tsukuba, Ibaraki, Japan, Research Center for Functional Materials, National Institute for Materials Science, Tsukuba 305-0044, Japan, International Center for Materials Nanoarchitectonics, National Institute for Materials, NIMS - Japan, National Institute for Materials Science ,Japan, National Institute for Materials Science, Tsukuba, 305-0044, Ibaraki, Japan, National Institute for Material Science, National Institute for Material Science, 1-1 Namiki, Tsukuba 305-0044, Japan, National Institute for Material Science Japan, NIMS Tsukuba, National Institute for Materials Science, Research Center for Functional Materials, Japan, Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan, National Institute for Materials Science: Namiki, Tsukuba, Ibaraki, JP, National Institue for Material Science, National Institute for Materials Science,1-1 Namiki, Tsukuba, 305-0044, Japan, Materials, NIMS, Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan, Research Center for Functional Materials, National In, Research Center for Functional Materials, Japan, International Center for Materials Nanoarchitectonics, National Institute for Materials Science, International Center for Materials nanoarchtectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan, NIMS Suguba, NIMS, Tsukuba, Japan, National Institute for Materials Science, Namiki 1-1, Tsukuba, 305-0044, Ibaraki, Japan, National institute of material science, Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan, Advanced Materials Laboratory, NIMS, Research Center for Functional Materials, National Institute for Materials Science, Ibaraki, Japan, National Institute for Materials Science, Research Center for Functional Materials, National Institute of Material Science, Japan, Tsukuba, National Institute for Materials Science

  • Andrea Young

    Department of Physics, University of California, Santa Barbara, University of California, Santa Barbara