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Van Hove driven symmetry breaking phases in twisted double bilayer graphene and superconductivity in a new twisted system

ORAL

Abstract

Two dimensional moire superlattices have emerged as a new playground for studying correlated physics. Various correlated phases including supercondcutivity, correlated insulators and metals, ferromagnetism and generalized Wigner crystal have been observed in twisted systems. These correlated phases have been generally attributed to the flat bands formed by hybridization between the two twisting layers. Here we forward the understanding of this connection between strong correlation and flat bands by studying the correlated phases in twisted double bilayer graphene (TDBG). We show that in TDBG, not only do we have spin-polarizaed correlated insulators as shown in our previous study, but also we have clear signatures of different isospin symmetry breaking phases and magnetic field induced Chern insulators. By comparing the transport measurements and single particle band calculation, we find that these symmetry breaking phases are closely related to the evolution of van Hove singularities in TDBG energy bands. In addition, we will show superconductivity in a new twisted system.

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Presenters

  • Zeyu Hao

    Harvard University

Authors

  • Zeyu Hao

    Harvard University

  • Andrew Zimmerman

    Harvard University

  • Xiaomeng Liu

    Princeton University

  • Yuval Ronen

    Harvard University

  • Danial Haei Najafabadi

    Harvard University

  • 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

  • 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

  • Philip Kim

    Harvard University