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

Abstract

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 model2-4. 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 belowmore » 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.:
Energy Frontier Research Centers (EFRC) (United States). Center for Novel Pathways to Quantum Coherence in Materials (NPQC); Stanford Univ., Redwood City, CA (United States); Lawrence Berkeley National Laboratory (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:
Accepted Manuscript
Journal Name:
Nature (London)
Additional Journal Information:
Journal Name: Nature (London); 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. https://doi.org/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. https://doi.org/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 model2-4. 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)},
number = 7768,
volume = 572,
place = {United States},
year = {Wed Jul 17 00:00:00 EDT 2019},
month = {Wed Jul 17 00:00:00 EDT 2019}
}

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Figures / Tables:

Fig. 1 Fig. 1: Mott insulator in trilayer graphene/hBN moiré superlattice. a, An optical image of the ABC-TLG/hBN device with top and bottom gates. Scale bar, 3 μm. b, A schematic of the triangular ABC-TLG/ hBN moiré superlattice and the 1/4-filling Mott insulating state, which corresponds to one hole per superlattice unitmore » cell. c, The single-particle energy dispersion of the lowest electron and hole minibands in the ABC-TLG/hBN superlattice with an effective potential energy difference between the bottom and top graphene layer of 2Δ = −20 meV, which can be generated by a vertical displacement field of −0.4 V nm−1. It features a narrow and isolated hole miniband, shown highlighted in red. d, Rxx as a function of carrier density shows prominent Mott insulating states at 1/4 and 1/2 fillings with D = −0.4 V nm−1 at T = 5 K. e, Two-dimensional colour plot of Rxx as a function of Vt and Vb at T = 5 K. The resistance peaks at 1/4 and 1/2 fillings of the first hole miniband can be clearly identified for relatively large D.« less

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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


Electron correlations in narrow energy bands. II. The degenerate band case
journal, January 1964

  • Hubbard, J.
  • Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, Vol. 277, Issue 1369, p. 237-259
  • DOI: 10.1098/rspa.1964.0019

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

Metal-insulator transitions
journal, June 1991


Strongly correlated Chern insulators in magic-angle twisted bilayer graphene
journal, December 2020


Isospin Pomeranchuk effect in twisted bilayer graphene
journal, April 2021


Trigonal warping and Berry's phase N pi in ABC-stacked multilayer graphene
text, January 2009


Band Structure of ABC-Stacked Graphene Trilayers
text, January 2010


Cloning of Dirac fermions in graphene superlattices
text, January 2012


Topological Superconductivity in Twisted Multilayer Graphene
text, January 2018


Atomic and electronic reconstruction at van der Waals interface in twisted bilayer graphene
text, January 2018


Tuning superconductivity in twisted bilayer graphene
text, January 2018


Works referencing / citing this record:

2D Materials for Large‐Area Flexible Thermoelectric Devices
journal, November 2019

  • Kanahashi, Kaito; Pu, Jiang; Takenobu, Taishi
  • Advanced Energy Materials, Vol. 10, Issue 11
  • DOI: 10.1002/aenm.201902842

Large-area epitaxial growth of curvature-stabilized ABC trilayer graphene
journal, January 2020


Tunable crystal symmetry in graphene–boron nitride heterostructures with coexisting moiré superlattices
journal, September 2019

  • Finney, Nathan R.; Yankowitz, Matthew; Muraleetharan, Lithurshanaa
  • Nature Nanotechnology, Vol. 14, Issue 11
  • DOI: 10.1038/s41565-019-0547-2

Strong correlations and orbital texture in single-layer 1T-TaSe2
journal, January 2020


Correlated states in twisted double bilayer graphene
journal, March 2020


Superconductors, orbital magnets and correlated states in magic-angle bilayer graphene
journal, October 2019


Tunable correlated Chern insulator and ferromagnetism in a moiré superlattice
journal, March 2020


Classifying superconductivity in Moiré graphene superlattices
journal, January 2020


Multifunctional inorganic nanomaterials for energy applications
journal, January 2020

  • Wang, Huilin; Liang, Xitong; Wang, Jiutian
  • Nanoscale, Vol. 12, Issue 1
  • DOI: 10.1039/c9nr07008g

Graphene-based spinmechatronic valve
journal, October 2019


Interacting valley Chern insulator and its topological imprint on moiré superconductors
journal, October 2019


Reconstruction of the Bi 2 Sr 2 CaCu 2 O 8 + δ Fermi surface
journal, December 2019


Pairing and non-Fermi liquid behavior in partially flat-band systems: Beyond nesting physics
journal, January 2020


Spin liquids and pseudogap metals in the SU(4) Hubbard model in a moiré superlattice
journal, January 2020


Cleaning interfaces in layered materials heterostructures
journal, December 2018


p-wave superconductivity in iron-based superconductors
journal, October 2019


Correlated states in twisted double bilayer graphene
text, January 2019


Geometric and conventional contribution to superfluid weight in twisted bilayer graphene
text, January 2019


Topological charge pumping in twisted bilayer graphene
text, January 2019