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The interplay of topological characteristics in real space and reciprocal space can lead to the emergence of unconventional topological phases. In this Letter, we implement a novel mechanism for generating higher-Chern flat bands on the…

Strongly Correlated Electrons · Physics 2021-11-23 Yifei Guan , Oleg V. Yazyev , Alexander Kruchkov

We construct a two-band lattice model whose bands can carry the Chern numbers C=0,pm1,pm2. By means of numerical exact diagonalization, we show that the most favorable situation that selects fractional Chern insulators (FCIs) is not…

Strongly Correlated Electrons · Physics 2012-11-26 Adolfo G. Grushin , Titus Neupert , Claudio Chamon , Christopher Mudry

We investigate topological band structures of a kagome system coupled to a circularly polarized cavity mode, using a model based on a muffin-tin potential and quantum light-matter interaction. We show that Chern insulating phases emerge in…

Mesoscale and Nanoscale Physics · Physics 2026-04-03 Hikaru Goto , Ryo Okugawa , Takami Tohyama

Chern insulators are band insulators exhibiting a nonzero Hall conductance but preserving the lattice translational symmetry. We conclusively show that a partially filled Chern insulator at 1/3 filling exhibits a fractional quantum Hall…

Strongly Correlated Electrons · Physics 2015-03-19 N. Regnault , B. Andrei Bernevig

Motivated by the higher Chern bands of twisted graphene multilayers, we consider flat bands with arbitrary Chern number $C$ with ideal quantum geometry. While $C>1$ bands differ from Landau levels, we show that these bands host exact…

Mesoscale and Nanoscale Physics · Physics 2023-07-25 Junkai Dong , Patrick J. Ledwith , Eslam Khalaf , Jong Yeon Lee , Ashvin Vishwanath

We investigate the electronic structure of the flat bands induced by moir\'e superlattices and electric fields in nearly aligned ABC trilayer graphene-boron nitride interfaces where Coulomb effects can lead to correlated gapped phases. Our…

Mesoscale and Nanoscale Physics · Physics 2019-01-09 Bheema Lingam Chittari , Guorui Chen , Yuanbo Zhang , Feng Wang , Jeil Jung

We propose models of twisted multilayer graphene that exhibit exactly flat Bloch bands with arbitrary Chern numbers and ideal band geometries. The models are constructed by twisting two sheets of Bernal-stacked multiple graphene layers with…

Mesoscale and Nanoscale Physics · Physics 2023-12-19 Jie Wang , Zhao Liu

We report the appearance of multiple numbers of completely flat band states in an extended Lieb lattice model in two dimensions with five atomic sites per unit cell. We also show that this edge-centered square lattice can host intriguing…

Strongly Correlated Electrons · Physics 2020-01-07 Ankita Bhattacharya , Biplab Pal

We demonstrate the realization of topological band structures by exploiting the intrinsic spin-orbit coupling of dipolar interactions in combination with broken time-reversal symmetry. The system is based on polar molecules trapped in a…

Flat bands, emergent in strongly correlated electron systems, stand at the frontier of condensed matter physics, providing fertile ground for unconventional quantum phases. Recent observations of dispersionless bands at the Fermi level in…

The Hofstadter model is a popular choice for theorists investigating the fractional quantum Hall effect on lattices, due to its simplicity, infinite selection of topological flat bands, and increasing applicability to real materials. In…

Strongly Correlated Electrons · Physics 2021-09-09 Bartholomew Andrews , Titus Neupert , Gunnar Möller

Isolated flat bands with significantly quenched kinetic energy of electrons could give rise to exotic strongly correlated states from electron-electron interactions. More intriguingly, the interplay between topology and flat bands can…

Mesoscale and Nanoscale Physics · Physics 2024-08-19 Huaiqiang Wang , Yiliang Fan , Haijun Zhang

We show that rhombohedral four-layer graphene (4LG) nearly aligned with a hexagonal boron nitride (hBN) substrate often develops nearly flat isolated low energy bands with non-zero valley Chern numbers. The bandwidths of the isolated…

Mesoscale and Nanoscale Physics · Physics 2023-11-28 Youngju Park , Yeonju Kim , Bheema Lingam Chittari , Jeil Jung

We present a simple prescription to flatten isolated Bloch bands with non-zero Chern number. We first show that approximate flattening of bands with non-zero Chern number is possible by tuning ratios of nearest-neighbor and next-nearest…

Strongly Correlated Electrons · Physics 2011-06-10 Titus Neupert , Luiz Santos , Claudio Chamon , Christopher Mudry

We construct generalized Hofstadter models that possess "color-entangled" flat bands and study interacting many-body states in such bands. For a system with periodic boundary conditions and appropriate interactions, there exist gapped…

Strongly Correlated Electrons · Physics 2015-01-29 Ying-Hai Wu , J. K. Jain , Kai Sun

Remarkable recent experiments on the moir\'e structure formed by pentalayer rhombohedral graphene aligned with a hexagonal Boron-Nitride substrate report the discovery of a zero field fractional quantum hall effect. These "(Fractional)…

Strongly Correlated Electrons · Physics 2024-12-10 Zhihuan Dong , Adarsh S. Patri , T. Senthil

We use a lowest Landau level model to study the recent observation of an anomalous Hall effect in twisted bilayer graphene. This effective model is rooted in the occurrence of Chern bands which arise due to the coupling between the graphene…

Strongly Correlated Electrons · Physics 2020-04-28 Nick Bultinck , Shubhayu Chatterjee , Michael P. Zaletel

We discuss a number of illuminating results for tight binding models supporting a band with variable Chern number, and illustrate them explicitly for a simple class of two-banded models. First, for models with a fixed number of bands, we…

Strongly Correlated Electrons · Physics 2014-10-21 Masafumi Udagawa , Emil J. Bergholtz

Motivated by new capabilities to realise artificial gauge fields in ultracold atomic systems, and by their potential to access correlated topological phases in lattice systems, we present a new strategy for designing topologically…

Quantum Gases · Physics 2012-11-22 N. R. Cooper , R. Moessner

We consider a rhombohedral-stacked $N$-layer graphene coupled to a monolayer of Haldane model. We show that high order Dirac points in multilayer graphene can be gapped out by topological proximity effect of the Haldane model layer, leading…

Mesoscale and Nanoscale Physics · Physics 2025-12-25 Yuejiu Zhao , Long Zhang , Fu-Chun Zhang