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Related papers: Flat-band ferromagnetism in twisted bilayer graphe…

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We present a comprehensive first-principles study of twisted bilayer graphene (tBLG) for a wide range of twist angles, with a focus on structural and electronic properties. By employing density functional theory (DFT) with an optimized…

Mesoscale and Nanoscale Physics · Physics 2026-05-13 Albert Zhu , Daniel Bennett , Daniel T. Larson , Mohammed M. Al Ezzi , Efstratios Manousakis , Efthimios Kaxiras

We investigate the electronic structure of alternating-twist triple Bernal-stacked bilayer graphene (t3BG) as a function of interlayer coupling $\omega$, twist angle $\theta$, interlayer potential difference $\Delta$, and top-bottom…

Mesoscale and Nanoscale Physics · Physics 2022-06-22 Jiseon Shin , Bheema Lingam Chittari , Yunsu Jang , Hongki Min , Jeil Jung

We analyze the electronic structure of twisted bilayer graphene (TBG) nanoribbons close to the magic angle. We describe a transition from an incomplete to a complete moir\'e structure. By considering zigzag and armchair edge terminations,…

Mesoscale and Nanoscale Physics · Physics 2023-09-14 Elias Andrade , Pierre A. Pantaleón , Francisco Guinea , Gerardo G. Naumis

We show that the flat bands in the chiral model of magic-angle twisted bilayer graphene remain exactly flat in the presence of a perpendicular magnetic field. This is shown by an exact mapping between the model and the lowest Landau level…

Strongly Correlated Electrons · Physics 2021-09-29 Yarden Sheffer , Ady Stern

Motivated by the study of flat bands in models of twisted bilayer graphene (TBG), we give abstract conditions which guarantee the existence of a discrete set of parameters for which periodic Hamiltonians exhibit flat bands. As an…

Analysis of PDEs · Mathematics 2023-09-12 Jeffrey Galkowski , Maciej Zworski

Twisted bilayer graphene (TBG) is known to have disorder in its twist angle. We show that in terms of a Dirac equation with a random gauge potential ${\bf A}({\bf r})$ this disorder becomes huge when the average twist angle is near the…

Mesoscale and Nanoscale Physics · Physics 2025-08-12 Baruch Horovitz , Pierre Le Doussal

In twisted bilayer graphene (TBLG), extremely small deviations from the magic twist angle $\theta_m{\approx}1.08^\circ$ change its electronic structure near the Fermi level drastically, causing a meV-wide flat band to appear or disappear.…

Mesoscale and Nanoscale Physics · Physics 2018-11-26 Xianqing Lin , Dan Liu , David Tománek

We study theoretically many-body properties of magic-angle twisted bilayer graphene for different doping levels. Our investigation is focused on the emergence, stability, and manifestations of nematicity of the ordered low-temperature…

Strongly Correlated Electrons · Physics 2020-10-29 A. O. Sboychakov , A. V. Rozhkov , A. L. Rakhmanov , Franco Nori

Here we present a theoretical analysis (applicable to all twist angles of TBG) of band dispersion and density of states in TBG relating evolution of flat band and Van-Hove singularities with evolution of interlayer coupling in TBG. A simple…

Mesoscale and Nanoscale Physics · Physics 2024-08-09 Veerpal , B. R. K. Nanda , Ajay

Twisted bilayer graphene (TBG) has elements in common with two paradigmatic examples of strongly correlated physics: quantum Hall physics and Hubbard physics. On one hand, TBG hosts flat topological Landau-level-like bands which exhibits…

Strongly Correlated Electrons · Physics 2026-05-29 Patrick J. Ledwith , Junkai Dong , Ashvin Vishwanath , Eslam Khalaf

Using a self-consistent Hartree-Fock theory, we show that the recently observed ferromagnetism in twisted bilayer WSe$_2$ [Nat. Commun. 16, 1959 (2025)] can be understood as a Stoner-like instability of interaction-renormalized moir\'e…

Strongly Correlated Electrons · Physics 2025-12-18 Liangtao Peng , Christophe De Beule , Yiyang Lai , Du Li , Li Yang , E. J. Mele , Shaffique Adam

Using exact diagonalization, we study the projected Hamiltonian with Coulomb interaction in the 8 flat bands of first magic angle twisted bilayer graphene. Employing the U(4) (U(4)$\times$U(4)) symmetries in the nonchiral (chiral) flat band…

Strongly Correlated Electrons · Physics 2022-04-26 Fang Xie , Aditya Cowsik , Zhi-Da Song , Biao Lian , B. Andrei Bernevig , Nicolas Regnault

Twisting is a novel technique for creating strongly correlated effects in two-dimensional bilayered materials, and can tunably generate nontrivial topological properties, magnetism, and superconductivity. Magnetism is particularly…

Strongly Correlated Electrons · Physics 2023-07-20 Zhigang Song , Jingshan Qi , Olivia Liebman , Prineha Narang

We introduce a complete physical model for the single-particle electronic structure of twisted bilayer graphene (tBLG), which incorporates the crucial role of lattice relaxation. Our model, based on $k \cdot p$ perturbation theory, combines…

Mesoscale and Nanoscale Physics · Physics 2019-08-14 Stephen Carr , Shiang Fang , Ziyan Zhu , Efthimios Kaxiras

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

Despite much theoretical work, developing a comprehensive ab initio model for twisted bilayer graphene (TBG) has proven challenging due to the inherent trade-off between accurately describing the band structure and incorporating the…

Strongly Correlated Electrons · Physics 2025-09-25 Run Hou , Shouvik Sur , Lucas K. Wagner , Andriy H. Nevidomskyy

Twisted bilayer graphene (TBG) exhibits a wide range of intriguing physical properties, such as superconductivity, ferromagnetism, and superlubricity. Depending on the twist angle, periodic moir\'e superlattices form in twisted bilayer…

Mesoscale and Nanoscale Physics · Physics 2022-06-07 Vahid Morovati , Zhiming Xue , Kenneth M. Liechti , Rui Huang

We describe the gated bilayer graphene system when it is subjected to intense terahertz frequency electromagnetic radiation. We examine the electron band structure and density of states via exact diagonalization methods within Floquet…

Mesoscale and Nanoscale Physics · Physics 2015-05-20 D. S. L. Abergel , Tapash Chakraborty

We investigate the topological heavy-fermion (THF) model of magic-angle twisted bilayer graphene (MATBG) in the projected limit, where only the flat bands are present in the low-energy spectrum. Such limit has been previously analyzed in…

Strongly Correlated Electrons · Physics 2025-10-20 Haoyu Hu , Zhi-Da Song , B. Andrei Bernevig

We present rigorous results for the SU($n$) Fermi-Hubbard model on the railroad-trestle lattice. We first study the model with a flat band at the bottom of the single-particle spectrum and prove that the ground states exhibit SU($n$)…

Strongly Correlated Electrons · Physics 2020-02-06 Kensuke Tamura , Hosho Katsura