English
Related papers

Related papers: Graph Theorem for Chiral Exact Flat Bands at Charg…

200 papers

High mobility single and few-layer graphene sheets are in many ways attractive as nanoelectronic circuit hosts but lack energy gaps, which are essential to the operation of field-effect transistors. One of the methods used to create gaps in…

Mesoscale and Nanoscale Physics · Physics 2018-12-26 Hakseong Kim , Nicolas Leconte , Bheema L. Chittari , Kenji Watanabe , Takashi Taniguchi , Allan H. MacDonald , Jeil Jung , Suyong Jung

The mechanisms of optical activity and quantum transport of twisted bilayer graphene are studied. The formation of unique electron states in the bilayer systems is studied using an effective continuum model. Such states are shown to support…

Mesoscale and Nanoscale Physics · Physics 2022-05-26 S. Ta Ho , V. Nam Do

Twisted double bilayer graphene is a compensated semi-metal near the charge neutrality point with the presence of small electron and hole pockets in its band structure. We show that strong Coulomb attraction between the electrons and holes…

Strongly Correlated Electrons · Physics 2023-07-26 Unmesh Ghorai , Ayan Ghosh , Anindya Das , Rajdeep Sensarma

Flatbands with extremely narrow bandwidths on the order of a few mili-electron volts can appear in twisted multilayer graphene systems for appropriate system parameters. Here we investigate the electronic structure of a twisted bi-bilayer…

Mesoscale and Nanoscale Physics · Physics 2019-06-24 Narasimha Raju Chebrolu , Bheema Lingam Chittari , Jeil Jung

We show that the continuum limit of moir\'e graphene is described by a $(2+1)$-dimensional field theory of Dirac fermions coupled to two classical vector fields: a periodic gauge and spin field. We further show that the existence of a flat…

Mesoscale and Nanoscale Physics · Physics 2024-09-17 Alireza Parhizkar , Victor Galitski

Recent experiments have observed strongly correlated physics in twisted bilayer graphene (TBG) at very small angles, along with nearly flat electron bands at certain fillings. A good starting point in understanding the physics is a…

Strongly Correlated Electrons · Physics 2019-01-16 Kasra Hejazi , Chunxiao Liu , Hassan Shapourian , Xiao Chen , Leon Balents

Flat band (FB) systems provide ideal playgrounds for studying correlation physics, whereas multi-orbital characteristics in real materials are distinguished from most simple FB models. Here, we propose a systematic and versatile framework…

Mesoscale and Nanoscale Physics · Physics 2026-03-24 Rui-Heng Liu , Xin Liu

Two-dimensional systems with flat bands support correlated phases such as superconductivity and charge fractionalization. While twisted moire systems like twisted bilayer graphene have revealed such states, they remain complex to control.…

Mesoscale and Nanoscale Physics · Physics 2025-07-02 Elias Andrade , Alejandro Jimeno-Pozo , Pierre A. Pantaleon , Francisco Guinea , Gerardo G. Naumis

Moir\'e materials host a wealth of intertwined correlated and topological states of matter, all arising from flat electronic bands with nontrivial quantum geometry. A prominent example is the family of alternating-twist magic-angle graphene…

The understanding of strongly-correlated materials, and in particular unconventional superconductors, has puzzled physicists for decades. Such difficulties have stimulated new research paradigms, such as ultra-cold atom lattices for…

Mesoscale and Nanoscale Physics · Physics 2018-05-22 Yuan Cao , Valla Fatemi , Shiang Fang , Kenji Watanabe , Takashi Taniguchi , Efthimios Kaxiras , Pablo Jarillo-Herrero

The recent discovery of superconductivity in magic-angle twisted bilayer graphene has sparked a renewed interest in the strongly-correlated physics of $sp^2$ carbons, in stark contrast to preliminary investigations which were dominated by…

Mesoscale and Nanoscale Physics · Physics 2023-02-17 Deepanshu Aggarwal , Rohit Narula , Sankalpa Ghosh

Moir\'e structures formed by twisting three layers of graphene with two independent twist angles present an ideal platform for studying correlated quantum phenomena, as an infinite set of angle pairs is predicted to exhibit flat bands.…

We propose an effective lattice model for the moir\'e structure of the twisted bilayer dice lattice. In the chiral limit, we find that there are flat bands at the zero-energy level at any twist angle besides the magic ones and these flat…

Mesoscale and Nanoscale Physics · Physics 2024-04-25 Di Ma , Yu-Ge Chen , Yue Yu , Xi Luo

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…

The incommensurate 30$^{\circ}$ twisted bilayer graphene (BG) possesses both relativistic Dirac fermions and quasiperiodicity with 12-fold rotational symmetry arising from the interlayer interaction…

Mesoscale and Nanoscale Physics · Physics 2022-03-14 Guodong Yu , Yunhua Wang , Mikhail I. Katsnelson , Hai-Qing Lin , Shengjun Yuan

The in-plane DC conductivity of twisted bilayer graphene (TBLG) is calculated using an expansion of the real-space Kubo-Bastin conductivity in terms of Chebyshev polynomials. We investigate within a tight-binding (TB) approach the transport…

Mesoscale and Nanoscale Physics · Physics 2018-03-28 M. Anđelković , L. Covaci , F. M. Peeters

Built on a realistic multiband tight-binding model, mirror symmetry is used to map a calcium-intercalated bilayer graphene Hamiltonian into two independent single layer graphene-like Hamiltonians with renormalized hopping. The…

Superconductivity · Physics 2020-02-03 Rouhollah Gholami , Rostam Moradian , Sina Moradian , Warren E. Pickett

The study of twisted bilayer graphene (TBG) is a hot topic in condensed matter physics with special focus on {\em magic angles} of twisting at which TBG acquires unusual properties. Mathematically, topologically non-trivial flat bands…

Mesoscale and Nanoscale Physics · Physics 2023-11-03 Maciej Zworski , Mengxuan Yang , Zhongkai Tao

Magic-angle ($\theta=1.05^\circ$) twisted bilayer graphene (MATBG) has shown two seemingly contradictory characters: the localization and quantum-dot-like behavior in STM experiments, and delocalization in transport experiments. We…

Strongly Correlated Electrons · Physics 2023-01-12 Zhi-Da Song , B. Andrei Bernevig

Superconductivity with transition temperature $T_c=1.7$ K has been reported in bilayer graphene [1,2]. The main factors, which may shed light on the mechanism of the formation of this superconductivity, are the following. Superconductivity…

Superconductivity · Physics 2018-06-22 G. E. Volovik