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Related papers: Heterostrain rules the flat-bands in magic-angle t…

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Twisting bilayer sheets of graphene have been proven to be an efficient way to manipulate the electronic Dirac-like properties, resulting in flat bands at magic angles. Inspired by the electronic model, we develop a continuum model for the…

Materials Science · Physics 2023-09-20 Emmanuele Cappelluti , Jose Angel Silva-Guillén , Habib Rostami , Francisco 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

Twisted bilayer graphene develop quasi-flat bands at specific "magic" interlayer rotation angles through an unconventional mechanism connected to carrier chirality. Quasi-flat bands are responsible for a wealth of exotic,…

Mesoscale and Nanoscale Physics · Physics 2020-11-25 María Rosendo , Fernando Peñaranda , Johan Christensen , Pablo San-Jose

Recent experiments show how a bilayer graphene twisted around a certain magic angle becomes superconducting as it is doped into a region with approximate flat bands. We investigate the mean-field $s$-wave superconducting state in such a…

Superconductivity · Physics 2018-12-19 T. J. Peltonen , R. Ojajärvi , T. T. Heikkilä

Twisted graphene bilayers show a complex electronic structure, further modified by interaction effects. The main features can be obtained from effective models, which make use a few phenomenological parameters. We analyze the influence of…

Strongly Correlated Electrons · Physics 2019-03-04 Niels R. Walet , Francisco Guinea

Twisted bilayer graphene displays many fascinating properties that can be tuned by varying the relative angle (also called twist angle) between its monolayers. As a remarkable feature, both the electronic flat bands and the corresponding…

Materials Science · Physics 2022-05-06 V. Hung Nguyen , Trinh X. Hoang , J. -C. Charlier

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

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

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 (tBLG) has emerged as a promising platform to explore exotic electronic phases. However, the formation of moir\'e patterns in tBLG has thus far been confined to the introduction of twist angles between the layers.…

Materials Science · Physics 2023-10-10 Gabriel R. Schleder , Michele Pizzochero , Efthimios Kaxiras

Twisted two-dimensional structures open new possibilities in band structure engineering. At magic twist angles, flat bands emerge, which give a new drive to the field of strongly correlated physics. In twisted double bilayer graphene dual…

We present a theoretical study of the effects of heterostrain and lattice relaxation on the optical conductivity of twisted bilayer graphene near the magic angle, based on the band structures obtained from a continuum model. We find that…

Mesoscale and Nanoscale Physics · Physics 2021-07-07 Zhen-Bing Dai , Yan He , Zhiqiang Li

Strong correlations occur in magic-angle twisted bilayer graphene (MATBG) when the octet of flat moir\'e minibands centered on charge neutrality (CN) is partially occupied. The octet consists of a single valence band and a single conduction…

Strongly Correlated Electrons · Physics 2024-10-18 Jihang Zhu , Iacopo Torre , Marco Polini , Allan H. MacDonald

We investigate twisted double bilayer graphene (TDBG), a four-layer system composed of two AB-stacked graphene bilayers rotated with respect to each other by a small angle. Our ab initio band structure calculations reveal a considerable…

Mesoscale and Nanoscale Physics · Physics 2020-04-22 Fatemeh Haddadi , QuanSheng Wu , Alex J. Kruchkov , Oleg V. Yazyev

Bilayer graphene was theorized to host a moire miniband with flat dispersion if the layers are stacked at specific twist angles known as the magic angles. Recently, such twisted bilayer graphene (tBLG) with the first magic angle twist was…

Electron interactions in quantum materials fundamentally shape their energy bands and, with them, the material's most intriguing quantum phases. Magic angle twisted bilayer graphene (MATBG) has emerged as a model system, where flat bands…

Mesoscale and Nanoscale Physics · Physics 2025-06-27 J. Xiao , A. Inbar , J. Birkbeck , N. Gershon , Y. Zamir , T. Taniguchi , K. Watanabe , E. Berg , S. Ilani

The electronic properties of van der Waals (vdW) structures can be substantially modified by the moire superlattice potential, which strongly depends on the twist angle among the compounds. In twisted bilayer graphene (TBG), two low-energy…

Materials Science · Physics 2020-12-02 Ya-Ning Ren , Yu Zhang , Yi-Wen Liu , Lin He

The symmetry-broken correlated states in twisted double bilayer graphene (TDBG) can be tuned via several external knobs, including twist angle, displacement field, and carrier density. However, a direct, momentum-resolved characterization…

Rotational misalignment or twisting of two mono-layers of graphene strongly influences its electronic properties. Structurally, twisting leads to large periodic supercell structures, which in turn can support intriguing strongly correlated…

Twisted bilayer graphene (TBG) has been experimentally observed to exhibit almost flat bands when the twisting occurs at certain magic angles. In this letter, we report new results on the continuum model of twisted bilayer graphene and its…

Strongly Correlated Electrons · Physics 2021-04-21 Simon Becker , Mark Embree , Jens Wittsten , Maciej Zworski