Emergence of flat-band magnetism and half-metallicity in twisted bilayer graphene
Abstract
Evidence of flat-band magnetism and half-metallicity in compressed twisted bilayer graphene is provided with first-principles calculations. In this article, we show that dynamic band-structure engineering in twisted bilayer graphene is possible by controlling the chemical composition with extrinsic doping, the interlayer coupling strength with pressure, and the magnetic ordering with external electric field. By varying the rotational order and reducing the interlayer separation, an unbalanced distribution of charge density results in the spontaneous apparition of localized magnetic moments without disrupting the structural integrity of the bilayer. Weak exchange correlation between magnetic moments is estimated in large unit cells. External electric field switches the local magnetic ordering from ferromagnetic to antiferromagnetic. Substitutional doping shifts the chemical potential of one spin distribution and leads to half-metallicity. Lastly, flakes of compressed twisted bilayer graphene exhibit spontaneous magnetization, demonstrating that correlation between magnetic moments is not a necessary condition for their formation.
- Publication Date:
- Research Org.:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Sponsoring Org.:
- USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), Basic Energy Sciences (BES)
- OSTI Identifier:
- 1529544
- Alternate Identifier(s):
- OSTI ID: 1518502
- Report Number(s):
- LA-UR-19-21862
Journal ID: ISSN 2475-9953; PRMHAR
- Grant/Contract Number:
- 89233218CNA000001
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Physical Review Materials
- Additional Journal Information:
- Journal Volume: 3; Journal Issue: 5; Journal ID: ISSN 2475-9953
- Publisher:
- American Physical Society (APS)
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 36 MATERIALS SCIENCE; Bilayer graphene; Magnetism; DFT
Citation Formats
Lopez-Bezanilla, Alejandro. Emergence of flat-band magnetism and half-metallicity in twisted bilayer graphene. United States: N. p., 2019.
Web. doi:10.1103/PhysRevMaterials.3.054003.
Lopez-Bezanilla, Alejandro. Emergence of flat-band magnetism and half-metallicity in twisted bilayer graphene. United States. https://doi.org/10.1103/PhysRevMaterials.3.054003
Lopez-Bezanilla, Alejandro. Tue .
"Emergence of flat-band magnetism and half-metallicity in twisted bilayer graphene". United States. https://doi.org/10.1103/PhysRevMaterials.3.054003. https://www.osti.gov/servlets/purl/1529544.
@article{osti_1529544,
title = {Emergence of flat-band magnetism and half-metallicity in twisted bilayer graphene},
author = {Lopez-Bezanilla, Alejandro},
abstractNote = {Evidence of flat-band magnetism and half-metallicity in compressed twisted bilayer graphene is provided with first-principles calculations. In this article, we show that dynamic band-structure engineering in twisted bilayer graphene is possible by controlling the chemical composition with extrinsic doping, the interlayer coupling strength with pressure, and the magnetic ordering with external electric field. By varying the rotational order and reducing the interlayer separation, an unbalanced distribution of charge density results in the spontaneous apparition of localized magnetic moments without disrupting the structural integrity of the bilayer. Weak exchange correlation between magnetic moments is estimated in large unit cells. External electric field switches the local magnetic ordering from ferromagnetic to antiferromagnetic. Substitutional doping shifts the chemical potential of one spin distribution and leads to half-metallicity. Lastly, flakes of compressed twisted bilayer graphene exhibit spontaneous magnetization, demonstrating that correlation between magnetic moments is not a necessary condition for their formation.},
doi = {10.1103/PhysRevMaterials.3.054003},
journal = {Physical Review Materials},
number = 5,
volume = 3,
place = {United States},
year = {2019},
month = {5}
}
Free Publicly Available Full Text
Publisher's Version of Record
Other availability
Search WorldCat to find libraries that may hold this journal
Cited by: 2 works
Citation information provided by
Web of Science
Web of Science
Save to My Library
You must Sign In or Create an Account in order to save documents to your library.
Works referenced in this record:
Two-dimensional van der Waals materials
journal, September 2016
- Ajayan, Pulickel; Kim, Philip; Banerjee, Kaustav
- Physics Today, Vol. 69, Issue 9
Lattice relaxation and energy band modulation in twisted bilayer graphene
journal, August 2017
- Nam, Nguyen N. T.; Koshino, Mikito
- Physical Review B, Vol. 96, Issue 7
Unconventional superconductivity in magic-angle graphene superlattices
journal, March 2018
- Cao, Yuan; Fatemi, Valla; Fang, Shiang
- Nature, Vol. 556, Issue 7699
Correlated insulator behaviour at half-filling in magic-angle graphene superlattices
journal, March 2018
- Cao, Yuan; Fatemi, Valla; Demir, Ahmet
- Nature, Vol. 556, Issue 7699
Theory of Phonon-Mediated Superconductivity in Twisted Bilayer Graphene
journal, December 2018
- Wu, Fengcheng; MacDonald, A. H.; Martin, Ivar
- Physical Review Letters, Vol. 121, Issue 25
Kohn-Luttinger Superconductivity in Twisted Bilayer Graphene
journal, January 2019
- González, J.; Stauber, T.
- Physical Review Letters, Vol. 122, Issue 2
The nature of correlations in the insulating states of twisted bilayer graphene
journal, March 2019
- Pizarro, J. M.; Calderón, M. J.; Bascones, E.
- Journal of Physics Communications, Vol. 3, Issue 3
Doped Twisted Bilayer Graphene near Magic Angles: Proximity to Wigner Crystallization, Not Mott Insulation
journal, September 2018
- Padhi, Bikash; Setty, Chandan; Phillips, Philip W.
- Nano Letters, Vol. 18, Issue 10
Dynamic band-structure tuning of graphene moiré superlattices with pressure
journal, May 2018
- Yankowitz, Matthew; Jung, Jeil; Laksono, Evan
- Nature, Vol. 557, Issue 7705
Tuning superconductivity in twisted bilayer graphene
journal, January 2019
- Yankowitz, Matthew; Chen, Shaowen; Polshyn, Hryhoriy
- Science, Vol. 363, Issue 6431
Pressure-induced magnetism in rotated graphene bilayers
journal, January 2019
- Yndurain, Felix
- Physical Review B, Vol. 99, Issue 4
Missing Atom as a Source of Carbon Magnetism
journal, March 2010
- Ugeda, M. M.; Brihuega, I.; Guinea, F.
- Physical Review Letters, Vol. 104, Issue 9
Upper Bound for the Magnetic Force Gradient in Graphite
journal, December 2010
- Martínez-Martín, David; Jaafar, Miriam; Pérez, Rubén
- Physical Review Letters, Vol. 105, Issue 25
Two theorems on the Hubbard model
journal, March 1989
- Lieb, Elliott H.
- Physical Review Letters, Vol. 62, Issue 10
Electrically Controllable Magnetism in Twisted Bilayer Graphene
journal, September 2017
- Gonzalez-Arraga, Luis A.; Lado, J. L.; Guinea, Francisco
- Physical Review Letters, Vol. 119, Issue 10
Self-consistent order- density-functional calculations for very large systems
journal, April 1996
- Ordejón, Pablo; Artacho, Emilio; Soler, José M.
- Physical Review B, Vol. 53, Issue 16
The SIESTA method for ab initio order- N materials simulation
journal, March 2002
- Soler, José M.; Artacho, Emilio; Gale, Julian D.
- Journal of Physics: Condensed Matter, Vol. 14, Issue 11
Efficient Implementation of a van der Waals Density Functional: Application to Double-Wall Carbon Nanotubes
journal, August 2009
- Román-Pérez, Guillermo; Soler, José M.
- Physical Review Letters, Vol. 103, Issue 9
Density functional calculations on the intricacies of Moiré patterns on graphite
journal, June 2007
- Campanera, J. M.; Savini, G.; Suarez-Martinez, I.
- Physical Review B, Vol. 75, Issue 23
Graphene Bilayer with a Twist: Electronic Structure
journal, December 2007
- Lopes dos Santos, J. M. B.; Peres, N. M. R.; Castro Neto, A. H.
- Physical Review Letters, Vol. 99, Issue 25
Twisted Bilayer Graphene: Moiré with a Twist
journal, August 2016
- Dai, Shuyang; Xiang, Yang; Srolovitz, David J.
- Nano Letters, Vol. 16, Issue 9
Pressure dependence of the magic twist angle in graphene superlattices
journal, August 2018
- Carr, Stephen; Fang, Shiang; Jarillo-Herrero, Pablo
- Physical Review B, Vol. 98, Issue 8
Charge Carriers in Few-Layer Graphene Films
journal, July 2006
- Latil, Sylvain; Henrard, Luc
- Physical Review Letters, Vol. 97, Issue 3
Massless fermions in multilayer graphitic systems with misoriented layers: Ab initio calculations and experimental fingerprints
journal, November 2007
- Latil, Sylvain; Meunier, Vincent; Henrard, Luc
- Physical Review B, Vol. 76, Issue 20
Numerical studies of confined states in rotated bilayers of graphene
journal, September 2012
- Trambly de Laissardière, G.; Mayou, D.; Magaud, L.
- Physical Review B, Vol. 86, Issue 12
Localization of Dirac Electrons in Rotated Graphene Bilayers
journal, March 2010
- Trambly de Laissardière, G.; Mayou, D.; Magaud, L.
- Nano Letters, Vol. 10, Issue 3
Skyrmions in the Moiré of van der Waals 2D Magnets
journal, October 2018
- Tong, Qingjun; Liu, Fei; Xiao, Jiang
- Nano Letters, Vol. 18, Issue 11
Direct observation of a widely tunable bandgap in bilayer graphene
journal, June 2009
- Zhang, Yuanbo; Tang, Tsung-Ta; Girit, Caglar
- Nature, Vol. 459, Issue 7248
Works referencing / citing this record:
Electrically Tunable Flat Bands and Magnetism in Twisted Bilayer Graphene
journal, August 2019
- Wolf, T. M. R.; Lado, J. L.; Blatter, G.
- Physical Review Letters, Vol. 123, Issue 9