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Twisted bilayer graphene (TBG) has extraordinary electronic properties at the magic angle along with an isolated flat band at the magic angle. However, the non-Hermitian phenomena in twisted bilayer graphene remain unexplored. In this work,…

Mesoscale and Nanoscale Physics · Physics 2025-02-17 Yingyi Huang

We study a 2D continuum model of electronic transport in twisted bilayer graphene (TBG) at commensurate angles. We use two honeycomb potentials with the symmetries of graphene, either sharing a common origin (AA stacking) or shifted by a…

Mathematical Physics · Physics 2026-05-19 Tal Malinovitch

We investigate correlated insulating states in magic-angle twisted bilayer graphene (TBG) by the exact diagonalization method applied to the extended Hubbard model with interaction parameters recently evaluated in the realistic effective…

Strongly Correlated Electrons · Physics 2018-08-08 Masayuki Ochi , Mikito Koshino , Kazuhiko Kuroki

Transport experiments in twisted bilayer graphene (TBG) show a fan-like region near integer fillings with a resistivity linear in temperature down to the lowest temperature measured. This suggests quantum-critical points at the boundaries…

Strongly Correlated Electrons · Physics 2023-12-29 C. M. Varma

The recently introduced topological heavy fermion model (THFM) provides a means for interpreting the low-energy electronic degrees of freedom of the magic angle twisted bilayer graphene as hybridization amidst highly dispersing topological…

Strongly Correlated Electrons · Physics 2024-06-25 Keshav Singh , Aaron Chew , Jonah Herzog-Arbeitman , B. Andrei Bernevig , Oskar Vafek

Twisted bilayer graphene (TBG) provides an example of a system in which the interplay of interlayer interactions and superlattice structure impacts electron transport in a variety of non-trivial ways and gives rise to a plethora of…

Mesoscale and Nanoscale Physics · Physics 2021-08-04 I. Y. Phinney , D. A. Bandurin , C. Collignon , I. A. Dmitriev , T. Taniguchi , K. Watanabe , P. Jarillo-Herrero

We develop an effective extended Hubbard model to describe the low-energy electronic properties of the twisted bilayer graphene. By using the Bloch states in the effective continuum model and with the aid of the maximally localized…

Mesoscale and Nanoscale Physics · Physics 2018-10-03 Mikito Koshino , Noah F. Q. Yuan , Takashi Koretsune , Masayuki Ochi , Kazuhiko Kuroki , Liang Fu

Song and Bernevig (SB) have recently proposed a topological heavy fermion description of the physics of magic angle twisted bilayer graphene (MATBG), involving the hybridization of flat band electrons with a relativistic conduction sea. We…

Strongly Correlated Electrons · Physics 2025-04-29 Liam L. H. Lau , Piers Coleman

Topological heavy fermion models[1-5] describe the flat bands in magic-angle twisted bilayer graphene (MATBG) as arising from the hybridization between localized flat-band orbitals (f-electrons) and nearly-free conduction bands…

Mesoscale and Nanoscale Physics · Physics 2025-03-25 Zhenyuan Zhang , Shuang Wu , Dumitru Călugăru , Haoyu Hu , Takashi Taniguchi , Kenji Wanatabe , Andrei B. Bernevig , Eva Y. Andrei

We present a theoretical investigation of the magnetic properties exhibited by twisted bilayer graphene (TBG) systems with small twist angles, where the appearance of flat minibands strongly enhances electron-electron interaction effects.…

Mesoscale and Nanoscale Physics · Physics 2025-04-08 Kevin J. U. Vidarte , Felipe Pérez Riffo , Eric Suárez Morell , Caio Lewenkopf

Twisted bilayer graphene near integer fillings hosts correlated single-particle excitations whose dispersion and linewidth are increasingly accessible experimentally. We study these excitations using the topological heavy-fermion model,…

We calculate the interactions between the Wannier functions of the 8-orbital model for twisted bilayer graphene (TBG). In this model, two orbitals per valley centered at the AA regions, the AA-p orbitals, account for the most part of the…

Strongly Correlated Electrons · Physics 2020-11-04 M. J. Calderón , E. Bascones

We consider confinement of Dirac fermions in $AB$-stacked bilayer graphene by inhomogeneous on-site interactions, (pseudo-)magnetic field or inter-layer interaction. Working within the framework of four-band approximation, we focus on the…

Mesoscale and Nanoscale Physics · Physics 2022-01-12 Miguel Castillo-Celeita , Vít Jakubský , Kevin Zelaya

We provide a method for the generation of effective continuum Hamiltonians that goes beyond the well known k.p method in being equally effective in both high, and low (or no) symmetry situations. Our approach is based on a surprising exact…

Mesoscale and Nanoscale Physics · Physics 2019-07-10 N. Ray , F. Rost , D. Weckbecker , M. Vogl , S. Sharma , R. Gupta , O. Pankratov , S. Shallcross

Ever since the initial experimental observation of correlated insulators and superconductivity in the flat Dirac bands of magic angle twisted bilayer graphene, a search for the microscopic description that explains its strong electronic…

Recent transport studies have demonstrated the great potential of twisted monolayer-bilayer graphene (tMBG) as a new platform to host moir\'e flat bands with a higher tunability than twisted bilayer graphene (tBG). However, a direct…

Mesoscale and Nanoscale Physics · Physics 2024-01-10 Ling-Hui Tong , Qingjun Tong , Li-Zhen Yang , Yue-Ying Zhou , Qilong Wu , Yuan Tian , Li Zhang , Lijie Zhang , Zhihui Qin , Long-Jing Yin

Bernal-stacked bilayer graphene (BLG) provides an ideal basis for gate-controlled, and free of etching, electronic devices. Theoretical modeling of realistic devices is an essential part of research, however, simulations of large-scale BLG…

Mesoscale and Nanoscale Physics · Physics 2024-08-16 Szu-Chao Chen , Alina Mreńca-Kolasińska , Ming-Hao Liu

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 investigate the electronic structure and transport properties of twisted bilayer graphene (TBLG) at a twist angle of $\theta\approx 1.696\text{{\deg}}$. Using a combination of molecular dynamics and tight-binding calculations, we find…

The conventional low-energy theory employed to describe twisted bilayer graphene (TBG) relies on a local interlayer Hamiltonian. According to this theory, TBG has the same linear-in-momentum dispersion and spinor wave function at the Dirac…

Mesoscale and Nanoscale Physics · Physics 2024-04-09 Hridis K. Pal