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Bilayer graphene twisted at the angle of about 1.1{\deg} better known as magic angle, exhibits ultra-flat moir\'e superlattice bands that are a source of highly-tunable, exotic quantum phenomena. Such phenomena, like superconductivity,…

Strongly Correlated Electrons · Physics 2024-11-05 Giovanna Feraco , Wissem Boubaker , Petra Rudolf , Antonija Grubišić-Čabo

Twisting two layers into a magic angle (MA) of ~1.1{\deg} is found essential to create low energy flat bands and the resulting correlated insulating, superconducting, and magnetic phases in twisted bilayer graphene (TBG). While most of…

We apply cluster dynamical mean field theory with an exact-diagonalization impurity solver to a Hubbard model for magic-angle twisted bilayer graphene, built on the tight-binding model proposed by Kang and Vafek (2018), which applies to the…

Strongly Correlated Electrons · Physics 2021-07-21 B. Pahlevanzadeh , P. Sahebsara , D. Sénéchal

In magic angle twisted bilayer graphene (MATBG), the moir\'e superlattice potential gives rise to narrow electronic bands1 which support a multitude of many-body quantum phases. Further richness arises in the presence of a perpendicular…

We report on a double moir\'e system consisting of four graphene layers, where the top and bottom pairs form small-twist-angle bilayer graphene, and the middle interface has a large rotational mismatch. This system shows clear signatures of…

Spontaneous orbital magnetism observed in twisted bilayer graphene (tBG) on nearly aligned hexagonal boron nitride (BN) substrate builds on top of the electronic structure resulting from combined G/G and G/BN double moire interfaces. Here…

Mesoscale and Nanoscale Physics · Physics 2021-02-24 Jiseon Shin , Youngju Park , Bheema Lingam Chittari , Jeil Jung

The discovery of correlated electronic phases, including Mott-like insulators and superconductivity, in twisted bilayer graphene (TBLG) near the magic angle, and the intriguing similarity of their phenomenology to that of the…

Mesoscale and Nanoscale Physics · Physics 2019-10-21 Yuhang Jiang , Jinhai Mao , Xinyuan Lai , Kenji Watanabe , Takashi Taniguchi , Kristjan Haule , Eva Y. Andrei

We consider magic-angle twisted bilayer graphene (TBG) at filling $\nu=+3$, where experiments have observed a robust quantized anomalous Hall effect. This has been attributed to the formation of a valley- and spin-polarized Chern insulating…

Strongly Correlated Electrons · Physics 2021-09-27 Yves H. Kwan , Glenn Wagner , Nilotpal Chakraborty , Steven H. Simon , S. A. Parameswaran

Recent experiments on magic-angle twisted bilayer graphene have discovered correlated insulating behavior and superconductivity at a fractional filling of an isolated narrow band. In this paper we show that magic-angle bilayer graphene…

Flat-bands in magic angle twisted bilayer graphene (MATBG) have recently emerged as a rich platform to explore strong correlations, superconductivity and mag-netism. However, the phases of MATBG in magnetic field, and what they reveal about…

Twisted bilayer graphene (TBG) is known for exhibiting highly correlated phases at magic angles due to the emergence of flat bands that enhance electron-electron interactions. In the TBG chiral model, electronic wave function properties…

Mesoscale and Nanoscale Physics · Physics 2023-09-15 Leonardo A. Navarro-Labastida , Gerardo G. Naumis

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

The recent discovery of correlated insulator states and superconductivity in magic-angle twisted bilayer graphene has paved the way to the experimental investigation of electronic correlations in tunable flat band systems realized in…

Studies of twisted moir\'e systems have been mainly focused on two-dimensional (2D) materials such as graphene with Dirac points and transition-metal-dichalcogenide so far. Here we propose a twisted bilayer of 2D systems which feature…

Strongly Correlated Electrons · Physics 2022-12-27 Ming-Rui Li , Ai-Lei He , Hong Yao

Correlated insulators and superconductivity have been observed in "magic-angle" twisted bilayer graphene, when the nearly flat bands close to neutrality are partially filled. While a momentum-space continuum model accurately describes these…

Strongly Correlated Electrons · Physics 2019-06-04 Hoi Chun Po , Liujun Zou , T. Senthil , Ashvin Vishwanath

Motivated by recent theoretical and experimental works on orbital magnetization $M_{\mathrm{orb}}$ for the interacting system, we develop a gauge-invariant framework to compute $M_{\mathrm{orb}}$ for correlated phases of magic-angle twisted…

Strongly Correlated Electrons · Physics 2026-04-20 Pinzhuo Li , Kun Jiang , Ziqiang Wang , Jian Kang , Yi Zhang

The unexpected discovery of superconductivity and strong electron correlation in twisted bilayer graphene (TBG), a system containing only sp electrons, is considered as one of the most intriguing developments in two-dimensional materials in…

Mesoscale and Nanoscale Physics · Physics 2025-04-22 Wei-Chen Wang , Feng-Wu Chen , Kuan-Sen Lin , Justin T. Hou , Ho-Chun Lin , Mei-Yin Chou

We review the theoretical modelling of moir\'e materials, focusing on various aspects of magic-angle twisted bilayer graphene (MA-TBG) viewed through the lens of Hartree-Fock mean-field theory. We first provide an elementary introduction to…

Strongly Correlated Electrons · Physics 2026-03-20 Yves H. Kwan , Ziwei Wang , Glenn Wagner , Nick Bultinck , Steven H. Simon , Siddharth A. Parameswaran

It was recently suggested that the topology of magic-angle twisted bilayer graphene's (MATBG) flat bands could provide a novel mechanism for superconductivity distinct from both weakly-coupled BCS theory and the $d$-wave phenomenology of…

Strongly Correlated Electrons · Physics 2022-07-27 Shubhayu Chatterjee , Matteo Ippoliti , Michael P. Zaletel

The strong coupling phase diagram of magic angle twisted bilayer graphene (TBG) predicts a series of exact one particle charge $\pm 1$ gapped excitations on top of the integer-filled ferromagnetic ground-states. Finite-size exact…

Strongly Correlated Electrons · Physics 2022-04-25 Frank Schindler , Oskar Vafek , B. Andrei Bernevig