Correlated insulating and superconducting states in twisted bilayer graphene below the magic angle

被引:151
|
作者
Codecido, Emilio [1 ]
Wang, Qiyue [2 ]
Koester, Ryan [1 ]
Che, Shi [1 ]
Tian, Haidong [1 ]
Lv, Rui [1 ]
Tran, Son [1 ]
Watanabe, Kenji [3 ]
Taniguchi, Takashi [3 ]
Zhang, Fan [2 ]
Bockrath, Marc [1 ]
Lau, Chun Ning [1 ]
机构
[1] Ohio State Univ, Dept Phys, 174 W 18th Ave, Columbus, OH 43210 USA
[2] Univ Texas Dallas, Dept Phys, Richardson, TX 75080 USA
[3] Natl Inst Mat Sci, 1-1 Namiki, Tsukuba, Ibaraki 3050044, Japan
来源
SCIENCE ADVANCES | 2019年 / 5卷 / 09期
关键词
DIRAC FERMIONS; MOIRE BANDS;
D O I
10.1126/sciadv.aaw9770
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
The emergence of flat bands and correlated behaviors in "magic angle" twisted bilayer graphene (tBLG) has sparked tremendous interest, though its many aspects are under intense debate. Here we report observation of both superconductivity and the Mott-like insulating state in a tBLG device with a twist angle of similar to 0.93 degrees, which is smaller than the magic angle by 15%. At an electron concentration of +/- 5 electrons/moire unit cell, we observe a narrow resistance peak with an activation energy gap similar to 0.1 meV. This indicates additional correlated insulating state, and is consistent with theory predicting a high-energy flat band. At doping of +/- 12 electrons/moire unit cell we observe resistance peaks arising from the Dirac points in the spectrum. Our results reveal that the "magic" range of tBLG is in fact larger than what is previously expected, and provide a wealth of new information to help decipher the strongly correlated phenomena observed in tBLG.
引用
收藏
页数:5
相关论文
共 50 条
  • [1] Fractional correlated insulating states at one-third filled magic angle twisted bilayer graphene
    Zhang, Kevin
    Zhang, Yang
    Fu, Liang
    Kim, Eun-Ah
    [J]. COMMUNICATIONS PHYSICS, 2022, 5 (01)
  • [2] Fractional correlated insulating states at one-third filled magic angle twisted bilayer graphene
    Kevin Zhang
    Yang Zhang
    Liang Fu
    Eun-Ah Kim
    [J]. Communications Physics, 5
  • [3] Possible correlated insulating states in magic-angle twisted bilayer graphene under strongly competing interactions
    Ochi, Masayuki
    Koshino, Mikito
    Kuroki, Kazuhiko
    [J]. PHYSICAL REVIEW B, 2018, 98 (08)
  • [4] Correlated Insulating States in Twisted Double Bilayer Graphene
    Burg, G. William
    Zhu, Jihang
    Taniguchi, Takashi
    Watanabe, Kenji
    MacDonald, Allan H.
    Tutuc, Emanuel
    [J]. PHYSICAL REVIEW LETTERS, 2019, 123 (19)
  • [5] Emergence of Chern Insulating States in Non-Magic Angle Twisted Bilayer Graphene
    沈成
    应江华
    刘乐
    刘健鹏
    李娜
    王硕培
    汤建
    赵岩翀
    褚衍邦
    Kenji Watanabe
    Takashi Taniguchi
    杨蓉
    时东霞
    屈凡明
    吕力
    杨威
    张广宇
    [J]. Chinese Physics Letters, 2021, 38 (04) : 106 - 120
  • [6] Emergence of Chern Insulating States in Non-Magic Angle Twisted Bilayer Graphene
    Shen, Cheng
    Ying, Jianghua
    Liu, Le
    Liu, Jianpeng
    Li, Na
    Wang, Shuopei
    Tang, Jian
    Zhao, Yanchong
    Chu, Yanbang
    Watanabe, Kenji
    Taniguchi, Takashi
    Yang, Rong
    Shi, Dongxia
    Qu, Fanming
    Lu, Li
    Yang, Wei
    Zhang, Guangyu
    [J]. CHINESE PHYSICS LETTERS, 2021, 38 (04)
  • [7] Correlated states in magic angle twisted bilayer graphene under the optical conductivity scrutiny
    Calderon, Maria J.
    Bascones, Elena
    [J]. NPJ QUANTUM MATERIALS, 2020, 5 (01)
  • [8] Correlated states in magic angle twisted bilayer graphene under the optical conductivity scrutiny
    María J. Calderón
    Elena Bascones
    [J]. npj Quantum Materials, 5
  • [9] Pseudospin Paramagnons and the Superconducting Dome in Magic Angle Twisted Bilayer Graphene
    Huang, Chunli
    Wei, Nemin
    Qin, Wei
    MacDonald, Allan H.
    [J]. PHYSICAL REVIEW LETTERS, 2022, 129 (18)
  • [10] Anderson's Theorem for Correlated Insulating States in Twisted Bilayer Graphene
    Kolar, Krystof
    Shavit, Gal
    Mora, Christophe
    Oreg, Yuval
    von Oppen, Felix
    [J]. PHYSICAL REVIEW LETTERS, 2023, 130 (07)