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Related papers: Moir\'{e} induced topology and flat bands in twist…

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Twisted bilayers of two-dimensional materials, such as twisted bilayer graphene, often feature flat electronic bands that enable the observation of electron correlation effects. In this work, we study the electronic structure of twisted…

Materials Science · Physics 2021-05-18 Valerio Vitale , Kemal Atalar , Arash A. Mostofi , Johannes Lischner

Motivated by recent experimental observations of opposite Chern numbers in $R$-type twisted MoTe$_2$ and WSe$_2$ homobilayers, we perform large-scale density-functional-theory (DFT) calculations with machine learning force fields to…

Materials Science · Physics 2024-05-21 Xiao-Wei Zhang , Chong Wang , Xiaoyu Liu , Yueyao Fan , Ting Cao , Di Xiao

The crystal structure of a material creates a periodic potential that electrons move through giving rise to the electronic band structure of the material. When two-dimensional materials are stacked, the twist angle between the layers…

Strongly Correlated Electrons · Physics 2020-07-07 Zhiming Zhang , Yimeng Wang , Kenji Watanabe , Takashi Taniguchi , Keiji Ueno , Emanuel Tutuc , Brian J. LeRoy

Twisted moir\'e superlattices hosting topological flat bands provide a platform to explore the interplay between topology and correlations. Here we investigate topological band structures in $\Gamma$-valley moir\'e systems based on…

Ultraflat bands in twisted bilayers of two-dimensional materials have potential to host strong correlations, including the Mott-insulating phase at half-filling of the band. Using first principles density functional theory calculations, we…

Materials Science · Physics 2019-01-02 Mit H. Naik , Manish Jain

The long wavelength moir\'e superlattices in twisted 2D structures have emerged as a highly tunable platform for strongly correlated electron physics. We study the moir\'e bands in twisted transition metal dichalcogenide homobilayers,…

Mesoscale and Nanoscale Physics · Physics 2021-11-19 Trithep Devakul , Valentin Crépel , Yang Zhang , Liang Fu

Topological flat bands formed in two-dimensional lattice systems offer unique opportunity to study the fractional phases of matter in the absence of an external magnetic field. Celebrated examples include fractional quantum anomalous Hall…

Experimental advances in the fabrication and characterization of few-layer materials stacked at a relative twist of small angle have recently shown the emergence of flat energy bands. As a consequence electron interactions become relevant,…

Strongly Correlated Electrons · Physics 2020-03-02 D. M. Kennes , L. Xian , M. Claassen , A. Rubio

The recent observation of correlated phases in transition metal dichalcogenide moir\'e systems at integer and fractional filling promises new insight into metal-insulator transitions and the unusual states of matter that can emerge near…

Moir\'e superlattices in van der Waals heterostructures provide a tunable platform to study emergent properties that are absent in the natural crystal form. Twisted bilayer transition metal dichalcogenides (TB-TMDs) can host moir\'e flat…

Mesoscale and Nanoscale Physics · Physics 2021-09-27 En Li , Jin-Xin Hu , Xuemeng Feng , Zishu Zhou , Liheng An , Kam Tuen Law , Ning Wang , Nian Lin

Moir\'e superlattices in the twisted bilayer graphene provide an unprecedented platform to investigate a wide range of exotic quantum phenomena. Recently, the twist degree of freedom has been introduced into various classical wave systems,…

Mesoscale and Nanoscale Physics · Physics 2021-12-01 Weixuan Zhang , Deyuan Zou , Qingsong Pei , Wenjing He , Houjun Sun , Xiangdong Zhang

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

1$T$-TaS$_2$ is the only insulating transition-metal dichalcogenide (TMD) with an odd number of electrons per unit cell. This insulating state is non-magnetic, making it a potential spin-liquid candidate. The unusual electronic behavior…

Strongly Correlated Electrons · Physics 2024-06-28 Amir Dalal , Jonathan Ruhman , Jörn W. F. Venderbos

We construct a continuum model for the Moir\'e superlattice of twisted bilayer MnBi$_2$Te$_4$, and study the band structure of the bilayer in both ferromagnetic (FM) and antiferromagnetic (AFM) phases. We find the system exhibits highly…

Mesoscale and Nanoscale Physics · Physics 2023-02-17 Biao Lian , Zhaochen Liu , Yuanbo Zhang , Jing Wang

The emergence of topologically non-trivial flat bands in moir\'e materials provides an opportunity to explore the interplay between topological physics and correlation effects, leading to the recent experimental realization of interacting…

Mesoscale and Nanoscale Physics · Physics 2024-05-24 Kaijie Yang , Yunzhe Liu , Frank Schindler , Chao-Xing Liu

We study the topological bands in twisted bilayer transition metal dichalcogenides in an external magnetic field. We first focus on a paradigmatic model of WSe$_2$, which can be described in an adiabatic approximation as particles moving in…

Mesoscale and Nanoscale Physics · Physics 2024-09-11 Kryštof Kolář , Kang Yang , Felix von Oppen , Christophe Mora

At magic twisted angles, Dirac cones in twisted bilayer graphene (TBG) can evolve into flat bands, serving as a critical playground for the study of strongly correlated physics. When chiral symmetry is introduced, rigorous mathematical…

Strongly Correlated Electrons · Physics 2023-10-11 Fan Cui , Congcong Le , Qiang Zhang , Xianxin Wu , Jiangping Hu , Ching-Kai Chiu

We experimentally investigate the band structures of chirally twisted triple bilayer graphene. The new kind of moir\'e structure, formed by three pieces of helically stacked Bernal bilayer graphene, has flat bands at charge neutral point…

Mesoscale and Nanoscale Physics · Physics 2025-01-14 Wenlu Lin , Wenxuan Wang , Shimin Cao , Miao Liang , Lili Zhao , Kenji Watanabe , Takashi Taniguchi , Jinhua Gao , Jianhao Chen , Xiaobo Lu , Yang Liu

Ultraflat bands have already been detected in twisted bilayer graphene and twisted bilayer transition-metal dichalcogenides, which provide a platform to investigate strong correlations. In this paper, the electronic properties of twisted…

Materials Science · Physics 2024-03-05 Yonggang Li , Zhen Zhan , Shengjun Yuan

We propose a tunable optical setup to engineer topologically nontrivial flat bands in twisted bilayer graphene under circularly polarized light. Using both analytical and numerical calculations, we demonstrate that nearly flat bands can be…

Strongly Correlated Electrons · Physics 2020-12-18 Yantao Li , H. A. Fertig , Babak Seradjeh