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Title: Signatures of tunable superconductivity in a trilayer graphene moiré superlattice

Abstract

Understanding the mechanism of high-transition-temperature (high-T c) superconductivity is a central problem in condensed matter physics. It is often speculated that high-Tc superconductivity arises in a doped Mott insulator1 as described by the Hubbard model 2,3,4. An exact solution of the Hubbard model, however, is extremely challenging owing to the strong electron–electron correlation in Mott insulators. Therefore, it is highly desirable to study a tunable Hubbard system, in which systematic investigations of the unconventional superconductivity and its evolution with the Hubbard parameters can deepen our understanding of the Hubbard model. Here we report signatures of tunable superconductivity in an ABC-trilayer graphene (TLG) and hexagonal boron nitride (hBN) moiré superlattice. Unlike in ‘magic angle’ twisted bilayer graphene, theoretical calculations show that under a vertical displacement field, the ABC-TLG/hBN heterostructure features an isolated flat valence miniband associated with a Hubbard model on a triangular superlattice 5,6 where the bandwidth can be tuned continuously with the vertical displacement field. Upon applying such a displacement field we find experimentally that the ABC-TLG/hBN superlattice displays Mott insulating states below 20 kelvin at one-quarter and one-half fillings of the states, corresponding to one and two holes per unit cell, respectively. Upon further cooling, signatures of superconductivitymore » (‘domes’) emerge below 1 kelvin for the electron- and hole-doped sides of the one-quarter-filling Mott state. The electronic behaviour in the ABC-TLG/hBN superlattice is expected to depend sensitively on the interplay between the electron–electron interaction and the miniband bandwidth. By varying the vertical displacement field, we demonstrate transitions from the candidate superconductor to Mott insulator and metallic phases. Our study shows that ABC-TLG/hBN heterostructures offer attractive model systems in which to explore rich correlated behaviour emerging in the tunable triangular Hubbard model.« less

Authors:
 [1];  [2];  [1];  [2];  [3];  [4];  [5];  [5];  [6];  [6];  [7];  [5];  [3];  [8];  [1]
  1. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States)
  2. Stanford Univ., CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States)
  3. SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., CA (United States)
  4. Univ. of California, Berkeley, CA (United States)
  5. Shanghai Jiao Tong Univ. (China); Collaborative Innovation Center of Advanced Microstructures, Nanjing (China)
  6. National Inst. for Materials Science (NIMS), Tsukuba (Japan)
  7. Univ. of Seoul, Seoul (Korea, Republic of)
  8. Collaborative Innovation Center of Advanced Microstructures, Nanjing (China); Fudan Univ., Shanghai (China)
Publication Date:
Research Org.:
Stanford Univ., Redwood City, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division
OSTI Identifier:
1545526
Alternate Identifier(s):
OSTI ID: 1619126
Grant/Contract Number:  
AC02-76SF00515; AC02-05CH11231
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Nature (London)
Additional Journal Information:
Journal Volume: 572; Journal Issue: 7768; Journal ID: ISSN 0028-0836
Publisher:
Nature Publishing Group
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

Citation Formats

Chen, Guorui, Sharpe, Aaron L., Gallagher, Patrick, Rosen, Ilan T., Fox, Eli J., Jiang, Lili, Lyu, Bosai, Li, Hongyuan, Watanabe, Kenji, Taniguchi, Takashi, Jung, Jeil, Shi, Zhiwen, Goldhaber-Gordon, David, Zhang, Yuanbo, and Wang, Feng. Signatures of tunable superconductivity in a trilayer graphene moiré superlattice. United States: N. p., 2019. Web. doi:10.1038/s41586-019-1393-y.
Chen, Guorui, Sharpe, Aaron L., Gallagher, Patrick, Rosen, Ilan T., Fox, Eli J., Jiang, Lili, Lyu, Bosai, Li, Hongyuan, Watanabe, Kenji, Taniguchi, Takashi, Jung, Jeil, Shi, Zhiwen, Goldhaber-Gordon, David, Zhang, Yuanbo, & Wang, Feng. Signatures of tunable superconductivity in a trilayer graphene moiré superlattice. United States. doi:10.1038/s41586-019-1393-y.
Chen, Guorui, Sharpe, Aaron L., Gallagher, Patrick, Rosen, Ilan T., Fox, Eli J., Jiang, Lili, Lyu, Bosai, Li, Hongyuan, Watanabe, Kenji, Taniguchi, Takashi, Jung, Jeil, Shi, Zhiwen, Goldhaber-Gordon, David, Zhang, Yuanbo, and Wang, Feng. Wed . "Signatures of tunable superconductivity in a trilayer graphene moiré superlattice". United States. doi:10.1038/s41586-019-1393-y. https://www.osti.gov/servlets/purl/1545526.
@article{osti_1545526,
title = {Signatures of tunable superconductivity in a trilayer graphene moiré superlattice},
author = {Chen, Guorui and Sharpe, Aaron L. and Gallagher, Patrick and Rosen, Ilan T. and Fox, Eli J. and Jiang, Lili and Lyu, Bosai and Li, Hongyuan and Watanabe, Kenji and Taniguchi, Takashi and Jung, Jeil and Shi, Zhiwen and Goldhaber-Gordon, David and Zhang, Yuanbo and Wang, Feng},
abstractNote = {Understanding the mechanism of high-transition-temperature (high-Tc) superconductivity is a central problem in condensed matter physics. It is often speculated that high-Tc superconductivity arises in a doped Mott insulator1 as described by the Hubbard model2,3,4. An exact solution of the Hubbard model, however, is extremely challenging owing to the strong electron–electron correlation in Mott insulators. Therefore, it is highly desirable to study a tunable Hubbard system, in which systematic investigations of the unconventional superconductivity and its evolution with the Hubbard parameters can deepen our understanding of the Hubbard model. Here we report signatures of tunable superconductivity in an ABC-trilayer graphene (TLG) and hexagonal boron nitride (hBN) moiré superlattice. Unlike in ‘magic angle’ twisted bilayer graphene, theoretical calculations show that under a vertical displacement field, the ABC-TLG/hBN heterostructure features an isolated flat valence miniband associated with a Hubbard model on a triangular superlattice5,6 where the bandwidth can be tuned continuously with the vertical displacement field. Upon applying such a displacement field we find experimentally that the ABC-TLG/hBN superlattice displays Mott insulating states below 20 kelvin at one-quarter and one-half fillings of the states, corresponding to one and two holes per unit cell, respectively. Upon further cooling, signatures of superconductivity (‘domes’) emerge below 1 kelvin for the electron- and hole-doped sides of the one-quarter-filling Mott state. The electronic behaviour in the ABC-TLG/hBN superlattice is expected to depend sensitively on the interplay between the electron–electron interaction and the miniband bandwidth. By varying the vertical displacement field, we demonstrate transitions from the candidate superconductor to Mott insulator and metallic phases. Our study shows that ABC-TLG/hBN heterostructures offer attractive model systems in which to explore rich correlated behaviour emerging in the tunable triangular Hubbard model.},
doi = {10.1038/s41586-019-1393-y},
journal = {Nature (London)},
issn = {0028-0836},
number = 7768,
volume = 572,
place = {United States},
year = {2019},
month = {7}
}

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Works referenced in this record:

Gate-Tunable Topological Flat Bands in Trilayer Graphene Boron-Nitride Moiré Superlattices
journal, January 2019


Epitaxial growth of single-domain graphene on hexagonal boron nitride
journal, July 2013

  • Yang, Wei; Chen, Guorui; Shi, Zhiwen
  • Nature Materials, Vol. 12, Issue 9
  • DOI: 10.1038/nmat3695

Topological Superconductivity in Twisted Multilayer Graphene
journal, August 2018


Unconventional superconductivity in magic-angle graphene superlattices
journal, March 2018


Nearly flat Chern bands in moiré superlattices
journal, February 2019


Hofstadter’s butterfly and the fractal quantum Hall effect in moiré superlattices
journal, May 2013


Topological valley transport at bilayer graphene domain walls
journal, April 2015


Cloning of Dirac fermions in graphene superlattices
journal, May 2013

  • Ponomarenko, L. A.; Gorbachev, R. V.; Yu, G. L.
  • Nature, Vol. 497, Issue 7451
  • DOI: 10.1038/nature12187

Bridging Hubbard model physics and quantum Hall physics in trilayer graphene / h BN moiré superlattice
journal, May 2019


Metal-insulator transitions
journal, October 1998

  • Imada, Masatoshi; Fujimori, Atsushi; Tokura, Yoshinori
  • Reviews of Modern Physics, Vol. 70, Issue 4, p. 1039-1263
  • DOI: 10.1103/RevModPhys.70.1039

Evidence of a gate-tunable Mott insulator in a trilayer graphene moiré superlattice
journal, January 2019


Ising pairing in superconducting NbSe2 atomic layers
journal, November 2015

  • Xi, Xiaoxiang; Wang, Zefang; Zhao, Weiwei
  • Nature Physics, Vol. 12, Issue 2
  • DOI: 10.1038/nphys3538

Stacking-dependent band gap and quantum transport in trilayer graphene
journal, September 2011

  • Bao, W.; Jing, L.; Velasco, J.
  • Nature Physics, Vol. 7, Issue 12
  • DOI: 10.1038/nphys2103

Observation of an electrically tunable band gap in trilayer graphene
journal, September 2011

  • Lui, Chun Hung; Li, Zhiqiang; Mak, Kin Fai
  • Nature Physics, Vol. 7, Issue 12
  • DOI: 10.1038/nphys2102

Electrically tunable low-density superconductivity in a monolayer topological insulator
journal, October 2018


The experimental observation of quantum Hall effect of l=3 chiral quasiparticles in trilayer graphene
journal, September 2011

  • Zhang, Liyuan; Zhang, Yan; Camacho, Jorge
  • Nature Physics, Vol. 7, Issue 12
  • DOI: 10.1038/nphys2104

Correlated insulator behaviour at half-filling in magic-angle graphene superlattices
journal, March 2018


One-Dimensional Electrical Contact to a Two-Dimensional Material
journal, October 2013


Charge imbalance observed in voltage-biased superconductor–normal tunnel junctions
journal, April 2006


Massive Dirac Fermions and Hofstadter Butterfly in a van der Waals Heterostructure
journal, May 2013


Atomic and electronic reconstruction at the van der Waals interface in twisted bilayer graphene
journal, April 2019


Band structure of A B C -stacked graphene trilayers
journal, July 2010


Tuning superconductivity in twisted bilayer graphene
journal, January 2019


Emergence of Tertiary Dirac Points in Graphene Moiré Superlattices
journal, May 2017


Trigonal warping and Berry’s phase N π in ABC-stacked multilayer graphene
journal, October 2009


Composite fermions and broken symmetries in graphene
journal, January 2015

  • Amet, F.; Bestwick, A. J.; Williams, J. R.
  • Nature Communications, Vol. 6, Issue 1
  • DOI: 10.1038/ncomms6838

Doping a Mott insulator: Physics of high-temperature superconductivity
journal, January 2006

  • Lee, Patrick A.; Nagaosa, Naoto; Wen, Xiao-Gang
  • Reviews of Modern Physics, Vol. 78, Issue 1
  • DOI: 10.1103/RevModPhys.78.17

Competition between spontaneous symmetry breaking and single-particle gaps in trilayer graphene
journal, December 2014

  • Lee, Y.; Tran, D.; Myhro, K.
  • Nature Communications, Vol. 5, Issue 1
  • DOI: 10.1038/ncomms6656

The influence of fluctuation pairing of electrons on the conductivity of normal metal
journal, February 1968


The Basis of the Electron Theory of Metals, with Special Reference to the Transition Metals
journal, July 1949


Tunable interacting composite fermion phases in a half-filled bilayer-graphene Landau level
journal, September 2017


Emergence of superlattice Dirac points in graphene on hexagonal boron nitride
journal, March 2012

  • Yankowitz, Matthew; Xue, Jiamin; Cormode, Daniel
  • Nature Physics, Vol. 8, Issue 5
  • DOI: 10.1038/nphys2272

    Works referencing / citing this record:

    Correlated states in twisted double bilayer graphene
    journal, March 2020