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Related papers: Valley Order in Moir\'e Topological Insulators

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We consider fractional quantum Hall states in systems where two flat Chern number $C=\pm 1$ bands are labeled by an approximately conserved 'valley' index and interchanged by time reversal symmetry. At filling factor $\nu=1$ this setting…

Strongly Correlated Electrons · Physics 2023-05-02 Yves H. Kwan , Yichen Hu , Steven H. Simon , S. A. Parameswaran

We study translationally-invariant insulators with inversion symmetry that fall outside the established classification of topological insulators. These insulators are not required to have gapless boundary modes in the energy spectrum.…

Mesoscale and Nanoscale Physics · Physics 2013-05-29 Taylor L. Hughes , Emil Prodan , B. Andrei Bernevig

The rapid development of moir\'e quantum matter has recently led to the remarkable discovery of the fractional quantum anomalous Hall effect, and sparked predictions of other novel correlation-driven topological states. Here, we investigate…

We investigate in detail the $\nu=+1$ displacement-field-tuned interacting phase diagram of $L=3,4,5,6,7$ layer rhombohedral graphene aligned to hBN (R$L$G/hBN). Our calculations account for the 3D nature of the Coulomb interaction, the…

Strongly Correlated Electrons · Physics 2025-10-08 Yves H. Kwan , Jiabin Yu , Jonah Herzog-Arbeitman , Dmitri K. Efetov , Nicolas Regnault , B. Andrei Bernevig

Magnetism typically arises from the joint effect of Fermi statistics and repulsive Coulomb interactions, which favors ground states with non-zero electron spin. As a result, controlling spin magnetism with electric fields---a longstanding…

Moir{\'e} superlattice realized in two-dimensional heterostructures offers an exciting platform to access strongly-correlated electronic states. In this work, we study transition metal dichalcogenides (TMD) Moir{\'e} superlattices with…

Mesoscale and Nanoscale Physics · Physics 2021-09-29 Heqiu Li , Umesh Kumar , Kai Sun , Shi-Zeng Lin

Recently, a quantum anomalous Hall (QAH) state was observed in AB stacked moir\'e MoTe$_2$/WSe$_2$ heterobilayers at half-filling. More recent layer-resolved magnetic circular dichroism (MCD) measurements revealed that spin-polarized…

Materials Science · Physics 2024-07-31 Ying-Ming Xie , Cheng-Ping Zhang , K. T. Law

Recent experimental discovery of fractional Chern insulator in moir\'e Chern band in twisted transition metal dichalocogenide homobilayers has sparked intensive interest in exploring the ways of engineering band topology and correlated…

Strongly Correlated Electrons · Physics 2024-05-22 Xiaoyang Shen , Chonghao Wang , Ruiping Guo , Zhiming Xu , Wenhui Duan , Yong Xu

By breaking the time-reversal-symmetry in three-dimensional topological insulators with introduction of spontaneous magnetization or application of magnetic field, the surface states become gapped, leading to quantum anomalous Hall effect…

Mesoscale and Nanoscale Physics · Physics 2019-06-26 R. Yoshimi , K. Yasuda , A. Tsukazaki , K. S. Takahashi , N. Nagaosa , M. Kawasaki , Y. Tokura

We investigate few- and many-body states in half-filled maximally symmetric topological insulator flat bands realized by two degenerate Landau levels which experience opposite magnetic fields. This serves as a toy model of flat bands in…

Strongly Correlated Electrons · Physics 2020-08-05 Nikolaos Stefanidis , Inti Sodemann

The interplay between strong electron-electron interaction and symmetry breaking can have profound influence on the topological properties of materials. In magic angle twisted bilayer graphene (MATBG), the flat band with a single SU(4)…

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…

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

We propose a new mechanism for quantum anomalous Hall (QAH) effect in the AB stacked MoTe$_2$/WSe$_2$ system. Based on the observation that the inter-layer tunneling is suppressed in the AB stacking, we consider a model with two layers…

Strongly Correlated Electrons · Physics 2023-02-15 Zhihuan Dong , Ya-Hui Zhang

Two-dimensional moire materials present unprecedented opportunities to explore quantum phases of matter arising from the interplay of band topology and strong correlations.One of the most striking examples is the recent observation of…

Moir\'e flatbands, occurring, e.g., in twisted bilayer graphene at magic angles, have attracted ample interest due to their high degree of experimental tunability and the intriguing possibility of generating novel strongly interacting…

Mesoscale and Nanoscale Physics · Physics 2020-03-17 Ahmed Abouelkomsan , Zhao Liu , Emil J. Bergholtz

Topological insulators are materials with a bulk excitation gap generated by the spin orbit interaction, and which are different from conventional insulators. This distinction is characterized by Z_2 topological invariants, which…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Liang Fu , C. L. Kane

Recently several moir\'e super-lattice systems are proposed to host nearly flat $\pm$ Chern bands: the bands of the two valleys have opposite Chern numbers. In these systems the charge of each valley is separately conserved. For the $C=\pm…

Strongly Correlated Electrons · Physics 2018-10-19 Ya-Hui Zhang

Studies on two-dimensional electron systems in a strong magnetic field first revealed the quantum Hall (QH) effect, a topological state of matter featuring a finite Chern number (C) and chiral edge states. Haldane later theorized that Chern…

We demonstrate that interacting electrons in AB-stacked $\mathrm{MoTe}_2/\mathrm{WSe}_2$ realize a topological Kondo insulator at hole filling $\nu=2$ per moir\'e unit cell. In the presence of only local correlations, a symmetry of the…

Strongly Correlated Electrons · Physics 2026-04-14 Andreas Gleis , Kevin Lucht , Po-Jui Chen , Daniele Guerci , Andrew J Millis , J. H. Pixley