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Related papers: Exciton fractional Chern insulators in moir\'e het…

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Electrons in moir\'e flat band systems can spontaneously break time reversal symmetry, giving rise to a quantized anomalous Hall effect. Here we use a superconducting quantum interference device to image stray magnetic fields in one such…

Mesoscale and Nanoscale Physics · Physics 2021-07-07 C. L. Tschirhart , M. Serlin , H. Polshyn , A. Shragai , Z. Xia , J. Zhu , Y. Zhang , K. Watanabe , T. Taniguchi , M. E. Huber , A. F. Young

We show that pressure applied to twisted WSe$_2$ can enhance the many-body gap and region of stability of a fractional Chern insulator at filling $\nu = 1/3$. Our results are based on exact diagonalization of a continuum model, whose…

Topological Mott insulator (TMI) with spontaneous time-reversal symmetry breaking and nonzero Chern number has been discovered in a real-space effective model for twisted bilayer graphene (TBG) at 3/4 filling in the strong coupling limit.…

Strongly Correlated Electrons · Physics 2022-05-26 Xiyue Lin , Bin-Bin Chen , Wei Li , Zi Yang Meng , Tao Shi

Inspired by experiments on magic angle twisted bilayer graphene, we present a lattice mean-field model for the quantum anomalous Hall effect in a moir\'e setting. Our hopping model thus provides a simple route to a moir\'e Chern insulator…

Mesoscale and Nanoscale Physics · Physics 2023-07-05 Ahmed Khalifa , Ganpathy Murthy , Ribhu K. Kaul

The possibility of realizing lattice analogs of fractional quantum Hall (FQH) states, so-called fractional Chern insulators (FCIs), in nearly flat topological (Chern) bands has attracted a lot of recent interest. Here, we make the…

Strongly Correlated Electrons · Physics 2013-01-16 Zhao Liu , Emil J. Bergholtz

Twisted bilayer transition metal dichalcogenide semiconductors, which support flat Chern bands with enhanced interaction effects, realize a platform for fractional Chern insulators and fractional quantum spin Hall (FQSH) insulators. A…

Mesoscale and Nanoscale Physics · Physics 2025-01-14 Kaifei Kang , Yichen Qiu , Bowen Shen , Kihong Lee , Zhengchao Xia , Yihang Zeng , Kenji Watanabe , Takashi Taniguchi , Jie Shan , Kin Fai Mak

Distinguished by their long lifetimes, strong dipolar interactions, and periodic confinement, moir\'e excitons provide a fertile territory for realizing interaction-driven excitonic phases beyond conventional semiconductor systems. Formed…

We propose a new mechanism to explain the quantum anomalous Hall (QAH) effect and the electric-field-induced topological phase transition in AB-stacked MoTe${}_2$/WSe${}_2$ moir\'e heterobilayers at $\nu=1$ hole filling. We suggest that the…

Mesoscale and Nanoscale Physics · Physics 2022-12-21 Yao-Wen Chang , Yia-Chung Chang

In three dimensional (3D) momentum space of solid crystal, a topological phase boundary separating the Chern insulating layers from normal insulating layers may exist, where the gap must be closed, resulting in a "Chern semi-metal" state…

Mesoscale and Nanoscale Physics · Physics 2012-02-24 Gang Xu , Hongming Weng , Zhijun Wang , Xi Dai , Zhong Fang

We study two models for spinless fermions featuring topologically non-trivial bands characterized by Chern numbers $C=\pm1$ at fractional filling. Using exact diagonalization, we show that, even for infinitely strong nearest-neighbor…

Strongly Correlated Electrons · Physics 2014-04-02 Stefanos Kourtis , Titus Neupert , Claudio Chamon , Christopher Mudry

Chern insulator or quantum anomalous Hall state is a topological state with integer Hall conductivity but in absence of Landau level. It had been well established on various two-dimensional lattices with periodic structure. Here, we report…

Mesoscale and Nanoscale Physics · Physics 2020-01-08 Ai-Lei He , Lu-Rong Ding , Yuan Zhou , Yi-Fei Wang , Chang-De Gong

Recent theoretical works have demonstrated various robust Abelian and non-Abelian fractional topological phases in lattice models with topological flat bands carrying Chern number C=1. Here we study hard-core bosons and interacting fermions…

Strongly Correlated Electrons · Physics 2012-11-07 Yi-Fei Wang , Hong Yao , Chang-De Gong , D. N. Sheng

We investigate the algebraic structure of flat energy bands a partial filling of which may give rise to a fractional quantum anomalous Hall effect (or a fractional Chern insulator) and a fractional quantum spin Hall effect. Both effects…

Mesoscale and Nanoscale Physics · Physics 2012-01-19 M. O. Goerbig

We propose a generalized composite fermion (CF) theory for fractional Chern insulators (FCIs) by adapting the quantum mechanics approach of CFs. The theoretical framework naturally produces an effective CF Hamiltonian and a wavefunction…

Strongly Correlated Electrons · Physics 2025-09-12 Hao Jin , Junren Shi

Fractional Chern insulators (FCIs) in ideal flat bands with Chern number $C$ are commonly understood as color-entangled states constructed from $C$ copies of the lowest Landau level. In realistic moir\'e systems, however, the band geometry…

Mesoscale and Nanoscale Physics · Physics 2025-11-25 Moru Song , Kai Chang

We investigate the fate of hardcore bosons in a Harper-Hofstadter model which was experimentally realized by Aidelsburger et al. [Nature Physics 11 , 162 (2015)] at half filling of the lowest band. We discuss the stability of an emergent…

Strongly Correlated Electrons · Physics 2017-10-20 Johannes Motruk , Frank Pollmann

We study four different models of Chern insulators in the presence of strong electronic repulsion at partial fillings. We observe that all cases exhibit a Laughlin-like phase at filling fraction 1/3. We provide evidence of such a strongly…

Strongly Correlated Electrons · Physics 2012-08-30 Yang-Le Wu , B. Andrei Bernevig , N. Regnault

A flat band with Chern number $C=0$, and well isolated from the rest of Hilbert space by a gap much larger than interaction strength, is a context that has not been regarded as relevant for fractional quantum Hall physics. In this work, we…

Mesoscale and Nanoscale Physics · Physics 2025-12-24 Zuzhang Lin , Hongyu Lu , Wenqi Yang , Dawei Zhai , Wang Yao

We study phases of itinerant anyons when hole-doping Laughlin-like states in fractional Chern insulators (FCIs). In light of the recent observation of time-reversal-broken superconductivity near FCIs in van der Waals materials, a…

Strongly Correlated Electrons · Physics 2026-03-25 Tevž Lotrič , Steven H. Simon

In twisted bilayer semiconductors with arbitrary twisting angles, a chiral excitonic system can arise from the interlayer electron-hole Coulomb exchange interaction (F\"{o}rster coupling) that hybridizes the anisotropic intralayer excitons…

Mesoscale and Nanoscale Physics · Physics 2024-09-23 Ci Li , Wang Yao