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Related papers: Broken Symmetry in Ideal Chern Bands

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In the presence of strong electronic interactions, a partially filled Chern band may stabilize a fractional Chern insulator (FCI) state, the zero-field analog of the fractional quantum Hall phase. While FCIs have long been hypothesized,…

Strongly Correlated Electrons · Physics 2024-10-15 Gal Shavit , Yuval Oreg

Recent experiments on bilayer graphene twisted near the magic angle have observed spontaneous integer quantum Hall states in the presence of an aligned hexagonal boron nitride (hBN) substrate. These states arise from valley ferromagnetism,…

Strongly Correlated Electrons · Physics 2020-06-18 Patrick J. Ledwith , Grigory Tarnopolsky , Eslam Khalaf , Ashvin Vishwanath

The integer quantum Hall state occurs when the Landau levels are fully occupied by the fermions, while the fractional quantum Hall state usually emerges when the Landau level is partially filled by the strongly correlated fermions or…

Strongly Correlated Electrons · Physics 2021-09-22 Wei-Wei Luo , Ai-Lei He , Yi-Fei Wang , Yuan Zhou , Chang-De Gong

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

Moir\'e flatbands with high Chern numbers (C>1) offer opportunities to study the fractional quantum anomalous Hall effects that go beyond the Landau level paradigm with C=1, which remain unexplored yet. Here, we target the novel topological…

Fractional quantum anomalous Hall (FQAH) effect, a lattice analogue of fractional quantum Hall effect, offers a unique pathway toward fault-tolerant quantum computation and deep insights into the interplay of topology and strong…

Mesoscale and Nanoscale Physics · Physics 2026-04-30 Wenqi Yang , Dawei Zhai , Wang Yao

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

Fractional Chern insulators realize the remarkable physics of the fractional quantum Hall effect (FQHE) in crystalline systems with Chern bands. The lowest Landau level (LLL) is known to host the FQHE, but not all Chern bands are suitable…

Strongly Correlated Electrons · Physics 2024-04-22 Patrick J. Ledwith , Ashvin Vishwanath , Daniel E. Parker

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

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 discuss the low-energy limit of three-orbital Kondo-lattice and Hubbard models describing $t_{2g}$ orbitals on a triangular lattice near half-filling. We analyze how very flat bands with non-trivial topological character, a Chern number…

Strongly Correlated Electrons · Physics 2015-03-20 Stefanos Kourtis , Jörn W. F. Venderbos , Maria Daghofer

A set of recent results indicates that fractionally filled bands of Chern insulators in two dimensions support fractional quantum Hall states analogous to those found in fractionally filled Landau levels. We provide an understanding of…

Strongly Correlated Electrons · Physics 2012-06-26 S. A. Parameswaran , R. Roy , S. L. Sondhi

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

As lattice analogs of fractional quantum Hall systems, fractional Chern insulators (FCIs) exhibit enigmatic physical properties resulting from the intricate interplay between single-body and many-body physics. In particular, the design of…

Strongly Correlated Electrons · Physics 2017-10-31 Ching Hua Lee , Martin Claassen , Ronny Thomale

We present a pedagogical review of the physics of fractional Chern insulators with a particular focus on the connection to the fractional quantum Hall effect. While the latter conventionally arises in semiconductor heterostructures at low…

Strongly Correlated Electrons · Physics 2015-10-05 S. A. Parameswaran , R. Roy , S. L. Sondhi

In the search of fractional quantum anomalous Hall (FQAH) effect, the conventional wisdom is to start from a flat Chern band isolated from the rest of the Hilbert space by band gaps, so that many-body interaction can be projected to a…

Mesoscale and Nanoscale Physics · Physics 2025-05-13 Wenqi Yang , Dawei Zhai , Tixuan Tan , Feng-Ren Fan , Zuzhang Lin , Wang Yao

Recent developments in fractional quantum Hall (FQH) physics highlight the importance of studying FQH phases of particles partially occupying energy bands that are not Landau levels. FQH phases in the regime of strong lattice effects,…

Strongly Correlated Electrons · Physics 2022-02-04 David Bauer , Spenser Talkington , Fenner Harper , Bartholomew Andrews , Rahul Roy

Helical trilayer graphene realizes a versatile moir\'e system for exploring correlated topological states emerging from high Chern bands. Motivated by recent experimental observations of anomalous Hall effects at fractional fillings of…

Strongly Correlated Electrons · Physics 2025-10-02 Sen Niu , Jason Alicea , D. N. Sheng , Yang Peng

The low-lying excitations of a quantum Hall state on a disk geometry are edge excitations. Their dynamics is governed by a conformal field theory on the cylinder defined by the disk boundary and the time variable. We give a simple and…

High Energy Physics - Theory · Physics 2009-10-22 A. Cappelli , G. V. Dunne , C. A. Trugenberger , G. R. Zemba

In this Letter, we study topological flat bands with distinct features that deviate from conventional Landau level behavior. We show that even in the ideal quantum geometry limit, moire flat band systems can exhibit physical phenomena…

Strongly Correlated Electrons · Physics 2025-11-27 Siddhartha Sarkar , Xiaohan Wan , Ang-Kun Wu , Shi-Zeng Lin , Kai Sun
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