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Related papers: Local spectroscopy of a gate-switchable moir\'e qu…

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Recently, fractional quantum anomalous Hall effects have been discovered in two-dimensional moir\'{e} materials when a topologically nontrivial band with Chern number $\mathcal{C}=1$ is partially doped. Remarkably, superlattice Bloch bands…

Mesoscale and Nanoscale Physics · Physics 2025-07-30 Vo Tien Phong , Cyprian Lewandowski

Graphene-based moire superlattices exhibit novel quantum phenomena driven by pronounced interactions, leading to topological corrected states like orbital Chern insulators exhibiting quantum anomalous Hall effect (QAHE). Typically,…

Mesoscale and Nanoscale Physics · Physics 2025-12-29 Zaizhe Zhang , Xi Chen , Kenji Watanabe , Takashi Taniguchi , Zhida Song , Xiaobo Lu

The quantum anomalous Hall (QAH) effect - a macroscopic manifestation of chiral band topology at zero magnetic field - has only been experimentally realized by magnetic doping of topological insulators (1 - 3) and delicate design of Moire…

Mesoscale and Nanoscale Physics · Physics 2021-10-14 Fabian R. Geisenhof , Felix Winterer , Anna M. Seiler , Jakob Lenz , Tianyi Xu , Fan Zhang , R. Thomas Weitz

We investigate an effective model of proximity modified graphene (or symmetrylike materials) with broken time-reversal symmetry. We predict the appearance of quantum anomalous Hall phases by computing bulk band gap and Chern numbers for…

Mesoscale and Nanoscale Physics · Physics 2020-04-07 Petra Högl , Tobias Frank , Klaus Zollner , Denis Kochan , Martin Gmitra , Jaroslav Fabian

The realization of fractional Chern insulators in moir\'e materials has sparked the search for further novel phases of matter in this platform. In particular, recent works have demonstrated the possibility of realizing quantum anomalous…

Mesoscale and Nanoscale Physics · Physics 2025-07-29 Raul Perea-Causin , Hui Liu , Emil J. Bergholtz

Twisted bilayer graphene (tBLG) forms a quasicrystal whose structural and electronic properties depend on the angle of rotation between its layers. Here we present a scanning tunneling microscopy study of gate-tunable tBLG devices supported…

Topological insulating states in two-dimensional (2D) materials are ideal systems to study different types of quantized response signals due to their in gap metallic states. Very recently, the quantum spin Hall (QSH) effect was discovered…

Mesoscale and Nanoscale Physics · Physics 2024-04-23 Junwen Lai , Xiangyang Liu , Jie Zhan , Tianye Yu , Peitao Liu , Xing-Qiu Chen , Yan Sun

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…

Quantum anomalous Hall insulators are topologically characterized by non-zero integer Chern numbers, the sign of which depends on the direction of the exchange field that breaks time-reversal symmetry. This feature allows the manipulation…

Mesoscale and Nanoscale Physics · Physics 2024-09-06 Nezhat Pournaghavi , Carlo M. Canali

We investigate the emergence of both quantum anomalous Hall and disorder-induced Anderson Chern insulating phases in two dimensional hexagonal lattices, with antiferromagnetically ordered 3Q state and in the absence of spin-orbit coupling.…

Mesoscale and Nanoscale Physics · Physics 2019-11-06 Papa Bireme Ndiaye , Adel Abbout , Aurelien Manchon

Interactions among electrons and the topology of their energy bands can create novel quantum phases of matter. Most topological electronic phases appear in systems with weak electron-electron interactions. The instances where topological…

Mesoscale and Nanoscale Physics · Physics 2020-12-25 Kevin P. Nuckolls , Myungchul Oh , Dillon Wong , Biao Lian , Kenji Watanabe , Takashi Taniguchi , B. Andrei Bernevig , Ali Yazdani

Quantum anomalous Hall (QAH) insulators are two-dimensional (2D) insulating states exhibiting properties similar to those of quantum Hall states but without external magnetic field. They have quantized Hall conductance $\sigma^H=Ce^2/h$,…

Mesoscale and Nanoscale Physics · Physics 2014-01-29 Chen Fang , Matthew J. Gilbert , B. Andrei Bernevig

We consider bilayer graphene in the presence of spin orbit coupling, to assess its behavior as a topological insulator. The first Chern number $n$ for the energy bands of single and bilayer graphene is computed and compared. It is shown…

Mesoscale and Nanoscale Physics · Physics 2011-07-18 E. Prada , P. San-Jose , L. Brey , H. A. Fertig

The flat bands resulting from moir\'e superlattices in magic-angle twisted bilayer graphene (MATBG) and ABC-trilayer graphene aligned with hexagonal boron nitride (ABC-TLG/hBN) have been shown to give rise to fascinating correlated electron…

Rhombohedral multilayer graphene, with its flat electronic bands and concentrated Berry curvature, is a promising material for the realization of correlated topological phases of matter. When aligned to an adjacent hexagonal boron nitride…

Mesoscale and Nanoscale Physics · Physics 2025-09-16 Samuel H. Aronson , Tonghang Han , Zhengguang Lu , Yuxuan Yao , Kenji Watanabe , Takashi Taniguchi , Long Ju , Raymond C. Ashoori

A peculiar feature of the majority of three dimensional topological insulator surface states studied experimentally thus far, namely their particle-hole asymmetry, makes quantum oscillations (Shubnikov de Haas and de Haas van Alphen…

Mesoscale and Nanoscale Physics · Physics 2013-03-14 Anthony R. Wright

The quantum anomalous Hall state with a large band gap and a high Chern number is significant for practical applications in spintronics. By performing first-principles calculations, we investigate electronic properties of the fully…

Mesoscale and Nanoscale Physics · Physics 2023-10-10 Zhen Zhang , Zhichao Zhou , Xiaoyu Wang , Huiqian Wang , Xiuling Li , Xiao Li

The isospin flavors in condensed matters can be continuously broken, forming various symmetry-broken quantum states. In moir\'e crystals, the competition between different isospin configurations can be effectively tuned by the twist angles…

Mesoscale and Nanoscale Physics · Physics 2026-01-08 Wenxuan Wang , Yijie Wang , Zaizhe Zhang , Zihao Huo , Gengdong Zhou , Kenji Watanabe , Takashi Taniguchi , X. C. Xie , Kaihui Liu , Zhida Song , Xiaobo Lu

When one of the graphene layers of Magic Angle Twisted Bilayer Graphene is nearly aligned with its hexagonal boron nitride substrate (a configuration dubbed TBG/hBN), the active electronic bands are nearly flat, and have a Chern number…

Strongly Correlated Electrons · Physics 2019-12-25 Cécile Repellin , T. Senthil

Over a long period of exploration, the successful observation of quantized version of anomalous Hall effect (AHE) in thin film of magnetically-doped topological insulator completed a quantum Hall trio---quantum Hall effect (QHE), quantum…

Mesoscale and Nanoscale Physics · Physics 2015-08-18 Hongming Weng , Rui Yu , Xiao Hu , Xi Dai , Zhong Fang