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If we stack up two layers of graphene while changing their respective orientation by some twisting angle, we end up with a system that has striking differences when compared to single-layer graphene. For a very specific value of this twist…

Mesoscale and Nanoscale Physics · Physics 2024-09-18 Eduardo B. Molinero , Anushree Datta , María J. Calderón , Elena Bascones , Rui E. F. Silva

A major hurdle in understanding the phase diagram of twisted bilayer graphene (TBLG) are the roles of lattice relaxation and electronic structure on isolated band flattening near magic twist angles. In this work, the authors develop an…

Mesoscale and Nanoscale Physics · Physics 2024-03-28 Shivesh Pathak , Tawfiqur Rakib , Run Hou , Andriy Nevidomskyy , Elif Ertekin , Harley T. Johnson , Lucas K. Wagner

Magic-angle twisted bilayer graphene (TBG) with its flat bands provides a rich platform for exploring emergent electronic orders. Similarly, periodically buckled monolayer graphene has been proposed as a tunable alternative for realizing…

Mesoscale and Nanoscale Physics · Physics 2025-10-16 Jannes van Poppelen , Annica M. Black-Schaffer

Twisted bilayer graphenes with magical angle exhibit strongly correlated electronic properties because of the isolated flat band at the Fermi level. We studied the twisted bilayer graphene with substrates on both layers. The substrate…

Mesoscale and Nanoscale Physics · Physics 2019-07-30 Ma Luo

We propose a tunable optical setup to engineer topologically nontrivial flat bands in twisted bilayer graphene under circularly polarized light. Using both analytical and numerical calculations, we demonstrate that nearly flat bands can be…

Strongly Correlated Electrons · Physics 2020-12-18 Yantao Li , H. A. Fertig , Babak Seradjeh

In this work, we study an interacting tight-binding model of magic-angle twisted bilayer graphene (MATBG), with a twist angle of $1.05^\circ$. We derive effective theories based on a mean-field normal state at charge neutrality, thereby…

Strongly Correlated Electrons · Physics 2025-05-27 Miguel Sánchez Sánchez , José González , Tobias Stauber

Flat band electronic modes in twisted graphene bilayers are responsible for superconducting and other highly correlated electron-electron phases. Although some hints were known of a possible connection between the quantum Hall effect and…

Mesoscale and Nanoscale Physics · Physics 2023-05-10 Leonardo A. Navarro-Labastida , Gerardo G. Naumis

Magic-angle twisted bilayer graphene (MATBG) exhibits correlated phenomena such as superconductivity and Mott insulating state related to the weakly dispersing flat band near the Fermi energy. Beyond its moir\'e period, such flat band is…

At certain angles of rotation called `magic angles' twisted bilayer graphene features almost flat bands. The resulting strong correlations drive the system to novel phases which have been observed in experiments recently. A complete…

Mesoscale and Nanoscale Physics · Physics 2018-11-01 Steven C. Carter , Hridis K. Pal , M. Kindermann

Twisted bilayer graphene (TBG) hosts nearly flat bands with narrow bandwidths of a few meV at certain {\em magic} twist angles. Here we show that in twisted gapped Dirac material bilayers, or massive twisted bilayer graphenes (MTBG),…

Mesoscale and Nanoscale Physics · Physics 2020-03-18 Srivani Javvaji , Jinhua Sun , Jeil Jung

Since the discovery of magic-angle twisted bilayer graphene (TBG), flat bands in Dirac materials have become a prominent platform for realizing strong correlation effects in electronic systems. Here we show that the symmetry group…

Strongly Correlated Electrons · Physics 2023-12-20 Yarden Sheffer , Raquel Queiroz , Ady Stern

Starting with twisted bilayer graphene, graphene-based moir\'e materials have recently been established as a new platform for studying strong electron correlations. In this paper, we study twisted graphene monolayers on trilayer graphene…

Graphene bilayers exhibit zero-energy flat bands at a discrete series of magic twist angles. In the absence of intra-sublattice inter-layer hopping, zero-energy states satisfy a Dirac equation with a non-abelian SU(2) gauge potential that…

Mesoscale and Nanoscale Physics · Physics 2021-01-13 Yafei Ren , Qiang Gao , A. H. MacDonald , Qian Niu

Theoretical and experimental studies have verified the existence of ``magic angles'' in twisted bilayer graphene, where the twist between layers gives rise to flat bands and consequently highly correlated phases. Narrow bands can also exist…

Strongly Correlated Electrons · Physics 2024-03-20 D. C. W. Foo , Z. Zhan , Mohammed M. Al Ezzi , L. Peng , S. Adam , F. Guinea

Stacked graphene multilayers with a small relative twist angle between each of the layers have been found to host flat bands at a series of magic angles. We consider the effect that Dirac point asymmetry between the layers, and in…

Mesoscale and Nanoscale Physics · Physics 2024-12-31 Adam Eaton , Yantao Li , Herbert Fertig , Babak Seradjeh

We construct an analytic continuum model to describe the electronic structure and the electron-phonon interaction in twisted bilayer graphenes with arbitrary lattice deformation. Starting from the tight-binding model, we derive the…

Mesoscale and Nanoscale Physics · Physics 2020-05-20 Mikito Koshino , Nguyen N. T. Nam

We investigate the effect of a magnetic field on the band structure of bilayer graphene with a magic twist angle of 1.08{\deg}. The coupling of a tight-binding model and the Peierls phase allows the calculation of the energy bands of…

Mesoscale and Nanoscale Physics · Physics 2024-05-20 Gaëlle Bigeard , Alessandro Cresti

When two monolayers of graphene are stacked with a small relative twist angle, the resulting band structure exhibits a remarkably flat pair of bands at a sequence of 'magic angles' where correlation effects can induce a host of exotic…

Strongly Correlated Electrons · Physics 2019-08-14 Eslam Khalaf , Alex J. Kruchkov , Grigory Tarnopolsky , Ashvin Vishwanath

The chiral Hamiltonian for twisted graphene bilayers is written as a $2\times2$ matrix operator by a renormalization of the Hamiltonian that takes into account the particle-hole symmetry. This results in an effective Hamiltonian with an…

Mesoscale and Nanoscale Physics · Physics 2023-08-01 Gerardo G. Naumis , Leonardo A. Navarro-Labastida , Enrique Aguilar-Méndez , Abdiel Espinosa-Champo

'Magic'-angle twisted bilayer graphene has received a lot of interest due to its flat bands with potentially non-trivial topology that lead to intricate correlated phases. A spectrum with flat bands, however, does not require a twist…

Mesoscale and Nanoscale Physics · Physics 2021-07-07 Anastasiia Skurativska , Stepan S. Tsirkin , Fabian D Natterer , Titus Neupert , Mark H Fischer