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Flat band electronic modes are responsible for superconductivity in twisted bilayer graphene (TBG) rotated at magic angles. From there other magic angles can be found for any multilayered twisted graphene systems. Eventually, this lead to…

Mesoscale and Nanoscale Physics · Physics 2022-12-15 Leonardo A. Navarro-Labastida , Gerardo G. Naumis

We present an infinite density-matrix renormalization group (DMRG) study of an interacting continuum model of twisted bilayer graphene (tBLG) near the magic angle. Because of the long-range Coulomb interaction and the large number of…

Strongly Correlated Electrons · Physics 2020-11-18 Tomohiro Soejima , Daniel E. Parker , Nick Bultinck , Johannes Hauschild , Michael P. Zaletel

The salient property of the electronic band structure of twisted bilayer graphene (TBG), at the so-called magic angle (MA), is the emergence of flat bands around the charge neutrality point. These bands are associated with the observed…

Mesoscale and Nanoscale Physics · Physics 2023-09-04 Sonia Haddad , Takeo Kato , Jihang Zhu , Lassaad Mandhour

We use the topological heavy fermion (THF) model and its Kondo Lattice (KL) formulation to study the symmetric Kondo state in twisted bilayer graphene. Via a large-N approximation, we find a symmetric Kondo (SK) state in KL mode at fillings…

Strongly Correlated Electrons · Physics 2023-11-06 H. Hu , G. Rai , L. Crippa , J. Herzog-Arbeitman , D. Călugăru , T. Wehling , G. Sangiovanni , R. Valenti , A. M. Tsvelik , B. A. Bernevig

We study the interacting transport properties of twisted bilayer graphene (TBG) using the topological heavy-fermion (THF) model. In the THF model, TBG comprises localized, correlated $f$-electrons and itinerant, dispersive $c$-electrons. We…

Strongly Correlated Electrons · Physics 2024-02-23 Dumitru Călugăru , Haoyu Hu , Rafael Luque Merino , Nicolas Regnault , Dmitri K. Efetov , B. Andrei Bernevig

In graphene, charged defects break the electron-hole symmetry and can even give rise to exotic collapse states when the defect charge exceeds a critical value which is proportional to the Fermi velocity. In this work, we investigate the…

A recent experiment reported a large anomalous Hall effect in Magic Angle Twisted Bilayer Graphene (TBG) aligned with a hexagonal boron nitride(h-BN) substrate at $\frac{3}{4}$ filling of the conduction band. In this paper we study this…

Strongly Correlated Electrons · Physics 2019-12-04 Ya-Hui Zhang , Dan Mao , T. Senthil

An accurate description of the low-energy electronic bands in twisted bilayer graphene (tBLG) is of great interest due to their relation to correlated electron phases, such as superconductivity and Mott-insulator behavior at half-filling.…

Mesoscale and Nanoscale Physics · Physics 2024-04-17 Daniel Bennett , Daniel T. Larson , Louis Sharma , Stephen Carr , Efthimios Kaxiras

Interplay of strong correlation and flat topological band has been a central problem in moir\'e systems such as the magic angle twisted bilayer graphene (TBG). Recent studies show that Mott-like states may still be possible in TBG despite…

Strongly Correlated Electrons · Physics 2025-07-02 Jing-Yu Zhao , Boran Zhou , Ya-Hui Zhang

We propose that the electronic structure of twisted bilayer graphene (TBG) can be understood as Dirac fermions coupled with opposite pseudo magnetic fields generated by the moir\'e pattern. The two low-energy flat bands from each monolayer…

Mesoscale and Nanoscale Physics · Physics 2019-04-24 Jianpeng Liu , Junwei Liu , Xi Dai

We investigate the Twisted Bilayer Graphene (TBG) model to obtain an analytic understanding of its energetics and wavefunctions needed for many-body calculations. We provide an approximation scheme which first elucidates why the BM…

Mesoscale and Nanoscale Physics · Physics 2022-04-29 B. Andrei Bernevig , Zhi-Da Song , Nicolas Regnault , Biao Lian

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 (MATBG) has been extensively explored both theoretically and experimentally as a suitable platform for a rich and tunable phase diagram that includes ferromagnetism, charge order, broken symmetries, and…

Mesoscale and Nanoscale Physics · Physics 2024-05-16 Lauro B. Braz , George B. Martins , Luis G. G. V. Dias da Silva

Magic-angle twisted bilayer graphene (MATBG) exhibits a rich variety of electronic states, including correlated insulators, superconductors, and topological phases. Understanding the microscopic mechanisms responsible for these phases…

Twisted bilayer graphene near the magic angle is known to have a cascade of insulating phases at integer filling factors of the low-energy bands. In this Letter we address the nature of these phases through an unrestricted, large-scale…

Strongly Correlated Electrons · Physics 2024-09-30 Khagendra Adhikari , Kangjun Seo , K. S. D. Beach , Bruno Uchoa

The nature of correlated states in twisted bilayer graphene (TBG) at the magic angle has received intense attention in recent years. We present a numerical study of an interacting Bistritzer-MacDonald (IBM) model of TBG using a suite of…

The flat bands of magic-angle twisted bilayer graphene (MATBG) host strongly-correlated electronic phases such as correlated insulators, superconductors and a strange-metal state. The latter state, believed to be key for understanding the…

New phases of matter can be stabilized by a combination of diverging electronic density of states, strong interactions, and spin-orbit coupling. Recent experiments in magic-angle twisted bilayer graphene (TBG) have uncovered a wealth of…

In this work we address the re-entrance of magic-angle phenomena (band flatness and quantum-geometric transport) in twisted bilayer graphene (TBG) subjected to strong magnetic fluxes $\pm \Phi_0$, $\pm 2 \Phi_0$, $\pm 3 \Phi_0$... ($\Phi_0…

Mesoscale and Nanoscale Physics · Physics 2022-10-04 Yifei Guan , Oleg V. Yazyev , Alexander Kruchkov

We propose a general principle for the low-energy theory of narrow bands with concentrated Berry curvature and Fubini-Study metric in the form of a map to Anderson-"+" models composed of heavy fermions hybridizing and interacting with…