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Title: Emergent ferromagnetism near three-quarters filling in twisted bilayer graphene

Abstract

When two sheets of graphene are stacked at a small twist angle, the resulting flat superlattice minibands are expected to strongly enhance electron-electron interactions. Here, we present evidence that near three-quarters ( 3 4 ) filling of the conduction miniband, these enhanced interactions drive the twisted bilayer graphene into a ferromagnetic state. In a narrow density range around an apparent insulating state at 3 4 , we observe emergent ferromagnetic hysteresis, with a giant anomalous Hall (AH) effect as large as 10.4 kilohms and indications of chiral edge states. Notably, the magnetization of the sample can be reversed by applying a small direct current. Although the AH resistance is not quantized, and dissipation is present, our measurements suggest that the system may be an incipient Chern insulator.

Authors:
ORCiD logo; ORCiD logo; ; ; ORCiD logo; ; ORCiD logo; ORCiD logo
Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Institute for Materials and Energy Science (SIMES)
Sponsoring Org.:
USDOE; USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division
OSTI Identifier:
1548254
Alternate Identifier(s):
OSTI ID: 1545527
Grant/Contract Number:  
AC02-76SF00515
Resource Type:
Published Article
Journal Name:
Science
Additional Journal Information:
Journal Name: Science Journal Volume: 365 Journal Issue: 6453; Journal ID: ISSN 0036-8075
Publisher:
American Association for the Advancement of Science (AAAS)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 36 MATERIALS SCIENCE

Citation Formats

Sharpe, Aaron L., Fox, Eli J., Barnard, Arthur W., Finney, Joe, Watanabe, Kenji, Taniguchi, Takashi, Kastner, M. A., and Goldhaber-Gordon, David. Emergent ferromagnetism near three-quarters filling in twisted bilayer graphene. United States: N. p., 2019. Web. doi:10.1126/science.aaw3780.
Sharpe, Aaron L., Fox, Eli J., Barnard, Arthur W., Finney, Joe, Watanabe, Kenji, Taniguchi, Takashi, Kastner, M. A., & Goldhaber-Gordon, David. Emergent ferromagnetism near three-quarters filling in twisted bilayer graphene. United States. https://doi.org/10.1126/science.aaw3780
Sharpe, Aaron L., Fox, Eli J., Barnard, Arthur W., Finney, Joe, Watanabe, Kenji, Taniguchi, Takashi, Kastner, M. A., and Goldhaber-Gordon, David. Thu . "Emergent ferromagnetism near three-quarters filling in twisted bilayer graphene". United States. https://doi.org/10.1126/science.aaw3780.
@article{osti_1548254,
title = {Emergent ferromagnetism near three-quarters filling in twisted bilayer graphene},
author = {Sharpe, Aaron L. and Fox, Eli J. and Barnard, Arthur W. and Finney, Joe and Watanabe, Kenji and Taniguchi, Takashi and Kastner, M. A. and Goldhaber-Gordon, David},
abstractNote = {When two sheets of graphene are stacked at a small twist angle, the resulting flat superlattice minibands are expected to strongly enhance electron-electron interactions. Here, we present evidence that near three-quarters ( 3 4 ) filling of the conduction miniband, these enhanced interactions drive the twisted bilayer graphene into a ferromagnetic state. In a narrow density range around an apparent insulating state at 3 4 , we observe emergent ferromagnetic hysteresis, with a giant anomalous Hall (AH) effect as large as 10.4 kilohms and indications of chiral edge states. Notably, the magnetization of the sample can be reversed by applying a small direct current. Although the AH resistance is not quantized, and dissipation is present, our measurements suggest that the system may be an incipient Chern insulator.},
doi = {10.1126/science.aaw3780},
journal = {Science},
number = 6453,
volume = 365,
place = {United States},
year = {2019},
month = {7}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
https://doi.org/10.1126/science.aaw3780

Citation Metrics:
Cited by: 128 works
Citation information provided by
Web of Science

Figures / Tables:

Figure 1 Figure 1: Correlated states in near-magic-angle TBG. (Upper panel) Longitudinal resistance Rxx of the TBG device (measured between contacts separated by 2.15 squares) as a function of carrier density n (shown on the top axis) and perpendicular displacement field D (left axis), which are tuned by the top- and back-gatemore » voltages, at 2.1 K. n is mapped to a filling factor relative to the superlattice density ns, corresponding to four electrons per moiré unit cell, shown on the bottom axis. (Inset) Optical micrograph of the completed device. The scale bar is 5 μm. (Lower panel) Line cut of Rxx with respect to n taken at D0 = −0.22 V/nm showing the resistance peaks at full filling of the superlattice, and additional peaks likely corresponding to correlated states emerging at intermediate fillings.« less

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Works referenced in this record:

Chiral transport along magnetic domain walls in the quantum anomalous Hall effect
journal, December 2017


Possible correlated insulating states in magic-angle twisted bilayer graphene under strongly competing interactions
journal, August 2018


Giant anomalous Hall effect in a ferromagnetic kagome-lattice semimetal
journal, July 2018


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


Generalized analysis of thermally activated domain-wall motion in Co/Pt multilayers
journal, March 2015

  • Emori, Satoru; Umachi, Chinedum K.; Bono, David C.
  • Journal of Magnetism and Magnetic Materials, Vol. 378
  • DOI: 10.1016/j.jmmm.2014.10.147

Scanning tunnelling microscopy and spectroscopy of ultra-flat graphene on hexagonal boron nitride
journal, February 2011

  • Xue, Jiamin; Sanchez-Yamagishi, Javier; Bulmash, Danny
  • Nature Materials, Vol. 10, Issue 4
  • DOI: 10.1038/nmat2968

Magnetoresistive Random Access Memory
journal, October 2016


Scale-Invariant Quantum Anomalous Hall Effect in Magnetic Topological Insulators beyond the Two-Dimensional Limit
journal, September 2014


Dirac-fermion-mediated ferromagnetism in a topological insulator
journal, August 2012

  • Checkelsky, Joseph G.; Ye, Jianting; Onose, Yoshinori
  • Nature Physics, Vol. 8, Issue 10
  • DOI: 10.1038/nphys2388

Imaging Cyclotron Orbits of Electrons in Graphene
journal, February 2016


Thin Films of Magnetically Doped Topological Insulator with Carrier-Independent Long-Range Ferromagnetic Order
journal, January 2013


Transport properties and magnetic interactions in acceptor-type magnetic graphite intercalation compounds
journal, July 1989


Chiral Majorana fermion modes in a quantum anomalous Hall insulator–superconductor structure
journal, July 2017


Heterostructures of bilayer graphene and h -BN: Interplay between misalignment, interlayer asymmetry, and trigonal warping
journal, November 2013


van der Waals Heterostructures with High Accuracy Rotational Alignment
journal, February 2016


Multilevel ferromagnetic behavior of room-temperature bulk magnetic graphite
journal, March 2005


Triangular antiferromagnetism on the honeycomb lattice of twisted bilayer graphene
journal, August 2018


Origin of band gaps in graphene on hexagonal boron nitride
journal, February 2015

  • Jung, Jeil; DaSilva, Ashley M.; MacDonald, Allan H.
  • Nature Communications, Vol. 6, Issue 1
  • DOI: 10.1038/ncomms7308

Two Dimensional Antiferromagnetic Chern Insulator: NiRuCl 6
journal, September 2016


Part-per-million quantization and current-induced breakdown of the quantum anomalous Hall effect
journal, August 2018


Zero-Field Dissipationless Chiral Edge Transport and the Nature of Dissipation in the Quantum Anomalous Hall State
journal, July 2015


Correlations and electronic order in a two-orbital honeycomb lattice model for twisted bilayer graphene
journal, December 2018


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


Anomalous Hall effect
journal, May 2010


Experimental evidence for a two-dimensional quantized Hall insulator
journal, October 1998

  • Hilke, M.; Shahar, D.; Song, S. H.
  • Nature, Vol. 395, Issue 6703
  • DOI: 10.1038/27160

Pressure-induced metal-insulator transition in twisted bilayer graphene
journal, May 2019


On the low-field Hall coefficient of graphite
journal, November 2014

  • Esquinazi, P.; Krüger, J.; Barzola-Quiquia, J.
  • AIP Advances, Vol. 4, Issue 11
  • DOI: 10.1063/1.4902099

Quantized chiral edge conduction on domain walls of a magnetic topological insulator
journal, December 2017


Itinerant Electron-Driven Chiral Magnetic Ordering and Spontaneous Quantum Hall Effect in Triangular Lattice Models
journal, October 2008


Electronic structure theory of weakly interacting bilayers
journal, June 2016


Nearly flat Chern bands in moiré superlattices
journal, February 2019


Experimental Observation of the Quantum Anomalous Hall Effect in a Magnetic Topological Insulator
journal, March 2013


Lattice relaxation and energy band modulation in twisted bilayer graphene
journal, August 2017


Room-temperature ferromagnetism in graphite driven by two-dimensional networks of point defects
journal, October 2009

  • Červenka, J.; Katsnelson, M. I.; Flipse, C. F. J.
  • Nature Physics, Vol. 5, Issue 11
  • DOI: 10.1038/nphys1399

Zero-field edge plasmons in a magnetic topological insulator
journal, November 2017


Anomalous Hall effect in graphite
journal, July 2006


Phases of a phenomenological model of twisted bilayer graphene
journal, August 2018


Interplay between Different Magnetisms in Cr-Doped Topological Insulators
journal, September 2013

  • Kou, Xufeng; Lang, Murong; Fan, Yabin
  • ACS Nano, Vol. 7, Issue 10
  • DOI: 10.1021/nn4038145

Trajectory of the anomalous Hall effect towards the quantized state in a ferromagnetic topological insulator
journal, August 2014

  • Checkelsky, J. G.; Yoshimi, R.; Tsukazaki, A.
  • Nature Physics, Vol. 10, Issue 10
  • DOI: 10.1038/nphys3053

Topological quantum computation based on chiral Majorana fermions
journal, October 2018

  • Lian, Biao; Sun, Xiao-Qi; Vaezi, Abolhassan
  • Proceedings of the National Academy of Sciences, Vol. 115, Issue 43
  • DOI: 10.1073/pnas.1810003115

Moire bands in twisted double-layer graphene
journal, July 2011

  • Bistritzer, R.; MacDonald, A. H.
  • Proceedings of the National Academy of Sciences, Vol. 108, Issue 30
  • DOI: 10.1073/pnas.1108174108

Insulating Behavior at the Neutrality Point in Single-Layer Graphene
journal, May 2013


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


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


Band structure of twisted bilayer graphene: Emergent symmetries, commensurate approximants, and Wannier obstructions
journal, August 2018


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


Tuning superconductivity in twisted bilayer graphene
journal, January 2019


Induced Magnetic Ordering by Proton Irradiation in Graphite
journal, November 2003


Anomalous Edge Transport in the Quantum Anomalous Hall State
journal, August 2013


Absence of backscattering in the quantum Hall effect in multiprobe conductors
journal, November 1988


Origin of Mott Insulating Behavior and Superconductivity in Twisted Bilayer Graphene
journal, September 2018


Superlattice-Induced Insulating States and Valley-Protected Orbits in Twisted Bilayer Graphene
journal, September 2016


Strong Coupling Phases of Partially Filled Twisted Bilayer Graphene Narrow Bands
journal, June 2019


Symmetry, Maximally Localized Wannier States, and a Low-Energy Model for Twisted Bilayer Graphene Narrow Bands
journal, September 2018


Ferromagnetic Mott state in Twisted Graphene Bilayers at the Magic Angle
journal, June 2019


Precise Quantization of the Anomalous Hall Effect near Zero Magnetic Field
journal, May 2015


Maximally Localized Wannier Orbitals and the Extended Hubbard Model for Twisted Bilayer Graphene
journal, September 2018


Substrate-induced band gap in graphene on hexagonal boron nitride: Ab initio density functional calculations
journal, August 2007


Global phase diagram in the quantum Hall effect
journal, July 1992


Quantized Anomalous Hall Effect in Magnetic Topological Insulators
journal, June 2010


Domain wall in a quantum anomalous Hall insulator as a magnetoelectric piston
journal, July 2016


Twisted bilayer graphene aligned with hexagonal boron nitride: Anomalous Hall effect and a lattice model
journal, November 2019


Works referencing / citing this record:

General continuum model for twisted bilayer graphene and arbitrary smooth deformations
journal, January 2019


Correlated states in twisted double bilayer graphene
journal, March 2020


General continuum model for twisted bilayer graphene and arbitrary smooth deformations
journal, January 2019


Theory of correlated insulating behaviour and spin-triplet superconductivity in twisted double bilayer graphene
journal, November 2019


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

Topological frustration induces unconventional magnetism in a nanographene
journal, December 2019


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


2D ferromagnetism in europium/graphene bilayers
journal, January 2020

  • Sokolov, Ivan S.; Averyanov, Dmitry V.; Parfenov, Oleg E.
  • Materials Horizons, Vol. 7, Issue 5
  • DOI: 10.1039/c9mh01988j

Singularities and topologically protected states in twisted bilayer graphene
journal, January 2020

  • Yao, Qirong; Chen, Xingchen; van Bremen, Rik
  • Applied Physics Letters, Vol. 116, Issue 1
  • DOI: 10.1063/1.5135071

Collective excitations in 2D atomic layers: Recent perspectives
journal, January 2020

  • Cho, Yujin; Huang, Jiahui; Wong, Chee Wei
  • Applied Physics Letters, Vol. 116, Issue 2
  • DOI: 10.1063/1.5135301

Graphene-based spinmechatronic valve
journal, October 2019


Moiré patterns: a simple analytical model
journal, November 2019


Cold atoms in twisted-bilayer optical potentials
journal, November 2019


Chiral twist on the high- T c phase diagram in moiré heterostructures
journal, August 2019


Intrinsic superstructure near atomically clean armchair step edges of graphite
journal, September 2019


Topological properties of multilayers and surface steps in the SnTe material class
journal, September 2019


Landau level degeneracy in twisted bilayer graphene: Role of symmetry breaking
journal, September 2019


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


Inherited and flatband-induced ordering in twisted graphene bilayers
journal, October 2019


Moiré-pattern fluctuations and electron-phason coupling in twisted bilayer graphene
journal, October 2019


SU(4) Heisenberg model on the honeycomb lattice with exchange-frustrated perturbations: Implications for twistronics and Mott insulators
journal, November 2019


Attractive electron-electron interactions from internal screening in magic-angle twisted bilayer graphene
journal, December 2019


Generic “unnecessary” quantum critical points with minimal degrees of freedom
journal, January 2020


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


Topological sliding moiré heterostructure
journal, January 2020


Correlated Insulating States in Twisted Double Bilayer Graphene
journal, November 2019


Collective Excitations of Quantum Anomalous Hall Ferromagnets in Twisted Bilayer Graphene
journal, January 2020


Strange Metal in Magic-Angle Graphene with near Planckian Dissipation
journal, February 2020


Nature of the Correlated Insulator States in Twisted Bilayer Graphene
journal, March 2020


Twisted bilayer graphene aligned with hexagonal boron nitride: Anomalous Hall effect and a lattice model
journal, November 2019


Anomalous chiral edge states in spin-1 Dirac quantum dots
journal, January 2020


Correlated insulating and superconducting states in twisted bilayer graphene below the magic angle
journal, September 2019


Intrinsic quantized anomalous Hall effect in a moiré heterostructure
journal, December 2019