English
Related papers

Related papers: Unconventional Flat Chern Bands and 2$e$ Charges i…

200 papers

In recent years, twisted bilayer graphene has become a hot topic and inspired the research upsurge of photonic moir\'e lattice. Here, we designed a photonic moir\'e superlattice with two synthetic twist angles and constructed a synthetic…

Optics · Physics 2023-05-17 Z. N. Liu , X. Q. Zhao , J. Yao , C. Zhang , J. L. Xu , S. N. Zhu , H. Liu

In two-dimensional electronic lattices, changes in the topology of the Fermi surface (Lifshitz transitions) lead to Van Hove singularities characterized by a divergence in the electronic density of states. Van Hove singularities can enhance…

Mesoscale and Nanoscale Physics · Physics 2024-02-27 Lakshmi Pullasseri , Luiz H. Santos

Twisted bilayer graphene (TBG) features strongly correlated and topological phases due to its flat bands emerging near the magic angle. However, the effects of the non-Hermiticity, arising from the coupling to the environment and…

Mesoscale and Nanoscale Physics · Physics 2025-06-06 Juan Pablo Esparza , Vladimir Juricic

Twisted double bilayer graphene (tDBG) has emerged as an especially rich platform for studying strongly correlated and topological states of matter. The material features moir\'e bands that can be continuously deformed by both perpendicular…

Mesoscale and Nanoscale Physics · Physics 2023-12-05 Minhao He , Jiaqi Cai , Ya-Hui Zhang , Yang Liu , Yuhao Li , Takashi Taniguchi , Kenji Watanabe , David H. Cobden , Matthew Yankowitz , Xiaodong Xu

The recent observation of the fractional quantum anomalous Hall effect in moir\'e fractional Chern insulators provides an opportunity to investigate zero magnetic field anyons. To potentially realize non-Abelian anyons, one approach is to…

We show that topological frequency band structures emerge in two-dimensional electromagnetic lattices of metamaterial components without the application of an external magnetic field. The topological nature of the band structure manifests…

Strongly Correlated Electrons · Physics 2015-06-05 Vassilios Yannopapas

Twisted bilayer graphene aligned with hexagonal boron nitride (TBG/hBN) hosts rich topological and correlated quantum phases, such as (fractional) Chern insulators, whose character is dictated by the topology of the moir\'{e} flat band.…

Strongly Correlated Electrons · Physics 2026-05-01 Huiwen Wang , Wei Jiang

Twisted $N$-layer graphene (TNG) moir\'e structures have recently been shown to exhibit robust superconductivity similar to twisted bilayer graphene (TBG). In particular for $N=4$ and $N=5$, the phase diagram features a superconducting…

Mesoscale and Nanoscale Physics · Physics 2023-07-18 Kryštof Kolář , Yiran Zhang , Stevan Nadj-Perge , Felix von Oppen , Cyprian Lewandowski

We propose Landau levels as a probe for the topological character of electronic bands in two-dimensional moir\'e superlattices. We consider two configurations of twisted double bilayer graphene (TDBG) that have very similar band structures,…

Mesoscale and Nanoscale Physics · Physics 2021-02-10 QuanSheng Wu , Jianpeng Liu , Oleg V. Yazyev

Lattice models forming bands with higher Chern number offer an intriguing possibility for new phases of matter with no analogue in continuum Landau levels. Here, we establish the existence of a number of new bulk insulating states at…

Strongly Correlated Electrons · Physics 2012-11-06 Zhao Liu , Emil J. Bergholtz , Heng Fan , Andreas M. Laeuchli

We report the discovery of a thermodynamically stable skyrmion-antiskyrmion lattice in two-dimensional heterostructures, a novel state exhibiting a net-zero global topological charge owing to an equal population of skyrmions and…

Materials Science · Physics 2025-10-23 Sayan Banik , Ashis K. Nandy

Flat bands in moir\'e superlattices provide a fertile ground for correlated and topological phases, governed by their quantum geometric properties. While the valley-based paradigm captures key features in select materials, it breaks down in…

Mesoscale and Nanoscale Physics · Physics 2026-05-19 Xiaoting Zhou , Yi-Chun Hung , Arun Bansil

Flat electronic bands, characteristic of magic-angle twisted bilayer graphene (TBG), host a wealth of correlated phenomena. Early theoretical considerations suggested that, at the magic angle, the Dirac velocity vanishes and the entire…

We report the theoretical discovery of a systematic scheme to produce topological flat bands (TFBs) with arbitrary Chern numbers. We find that generically a multi-orbital high Chern number TFB model can be constructed by considering…

Strongly Correlated Electrons · Physics 2013-01-01 Shuo Yang , Zheng-Cheng Gu , Kai Sun , S. Das Sarma

We illustrate the possibility of realizing band gaps in graphene-like systems that fall outside the existing classification of gapped Dirac Hamiltonians in terms of masses. As our primary example we consider a band gap arising due to…

Mesoscale and Nanoscale Physics · Physics 2014-03-31 Thomas Iadecola , Titus Neupert , Claudio Chamon

The discovery of zero-field fractional Chern insulators (FCIs) in moir\'e materials has attracted intense interest in the interplay between topology and correlations. Here, we demonstrate that fractionalized topological order can emerge…

Mesoscale and Nanoscale Physics · Physics 2025-10-20 Hui Liu , Raul Perea-Causin , Zhao Liu , Emil J. Bergholtz

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

Inter-twisted bilayers of two-dimensional (2D) materials can host low-energy flat bands, which offer opportunity to investigate many intriguing physics associated with strong electron correlations. In the existing systems, ultra-flat bands…

Computational Physics · Physics 2022-03-01 Shengdan Tao , Xuanlin Zhang , Jiaojiao Zhu , Pimo He , Shengyuan A. Yang , Yunhao Lu , Su-Huai Wei

Graphene moir\'e superlattices display electronic flat bands. At integer fillings of these flat bands, energy gaps due to strong electron-electron interactions are generally observed. However, the presence of other correlation-driven phases…

Bilayer graphene twisted at the angle of about 1.1{\deg} better known as magic angle, exhibits ultra-flat moir\'e superlattice bands that are a source of highly-tunable, exotic quantum phenomena. Such phenomena, like superconductivity,…

Strongly Correlated Electrons · Physics 2024-11-05 Giovanna Feraco , Wissem Boubaker , Petra Rudolf , Antonija Grubišić-Čabo