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Related papers: Tuning Chern Number in Quantum Anomalous Hall Insu…

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Recently Chern insulators with Chern number $C=1$ and $C=2$ in zero (or very small) magnetic field have been observed in two moire graphene systems: twisted bilayer graphene and ABC trilayer graphene, both aligned with a hexagonal…

Strongly Correlated Electrons · Physics 2020-10-07 Ya-Hui Zhang , T. Senthil

Chern insulators are two-dimensional magnetic topological materials that conduct electricity along their edges via the one-dimensional chiral modes. The number of these modes is a topological invariant called the first Chern number $C$,…

Mesoscale and Nanoscale Physics · Physics 2022-12-29 Mihovil Bosnar , Alexandra Yu. Vyazovskaya , Evgeniy K. Petrov , Evgueni V. Chulkov , Mikhail M. Otrokov

The quantum anomalous Hall system with Chern number 2 can be destroyed by sufficiently strong disorder. During its process towards localization, it was found that the electronic states will be directly localized to an Anderson insulator…

Mesoscale and Nanoscale Physics · Physics 2016-01-12 Zhi-Gang Song , Yan-Yang Zhang , Jun-Tao Song , Shu-Shen Li

We investigate topological phases of bilayer graphene subject to antiferromagnetic exchange field, interlayer bias, and irradiated by light. We discover that at finite bias and light intensity the system transitions into a previously…

Mesoscale and Nanoscale Physics · Physics 2020-04-29 Xuechao Zhai , Yaroslav M. Blanter

We report the observation of a quantum anomalous Hall effect in twisted bilayer graphene showing Hall resistance quantized to within .1\% of the von Klitzing constant $h/e^2$ at zero magnetic field.The effect is driven by intrinsic strong…

Strongly Correlated Electrons · Physics 2020-03-18 M. Serlin , C. L. Tschirhart , H. Polshyn , Y. Zhang , J. Zhu , K. Watanabe , T. Taniguchi , L. Balents , A. F. Young

Remarkable recent experiments on the moir\'e structure formed by pentalayer rhombohedral graphene aligned with a hexagonal Boron-Nitride substrate report the discovery of a zero field fractional quantum hall effect. These "(Fractional)…

Strongly Correlated Electrons · Physics 2024-12-10 Zhihuan Dong , Adarsh S. Patri , T. Senthil

We propose a new mechanism to explain the quantum anomalous Hall (QAH) effect and the electric-field-induced topological phase transition in AB-stacked MoTe${}_2$/WSe${}_2$ moir\'e heterobilayers at $\nu=1$ hole filling. We suggest that the…

Mesoscale and Nanoscale Physics · Physics 2022-12-21 Yao-Wen Chang , Yia-Chung Chang

The study of topological property of band insulators is an interesting branch of condensed matter physics. Two types of topologically nontrivial insulators have been extensively studied. The first type is characterized by a nonzero TKNN…

Materials Science · Physics 2011-11-15 Yi-Dong Wu

Spin-orbit coupling (SOC) is thought to be necessary in realizing quantum anomalous Hall (QAH) insulators in magnetic materials. In this Letter, we propose an exciton-condensation mechanism to realize QAH effect in collinear magnets with…

Mesoscale and Nanoscale Physics · Physics 2026-03-16 Xingxing Liu , ChaoYang Tan , Peng-Jie Guo , Zhong-Yi Lu , Zheng-Xin Liu

The understanding of the Chern insulator and anomalous quantum Hall effect (AQHE) in terms of chiral edge states in confined systems is the first aim of the paper. The model we use consists in a diatomic square lattice with hopping to the…

Mesoscale and Nanoscale Physics · Physics 2018-09-12 B. Ostahie , M. Nita , A. Aldea

The quantum anomalous Hall (QAH) effect is predicted to possess, at zero magnetic field, chiral edge channels that conduct spin polarized current without dissipation. While edge channels have been observed in previous experimental studies…

Mesoscale and Nanoscale Physics · Physics 2015-08-20 Cui-Zu Chang , Weiwei Zhao , Duk Y. Kim , Peng Wei , J. K. Jain , Chaoxing Liu , Moses H. W. Chan , Jagadeesh S. Moodera

In magnetically doped thin-film topological insulators, aligning the magnetic moments generates a quantum anomalous Hall phase supporting a single chiral edge state. We show that as the system de-magnetizes, disorder from randomly oriented…

Mesoscale and Nanoscale Physics · Physics 2019-07-30 Arbel Haim , Roni Ilan , Jason Alicea

Quantum anomalous Hall (QAH) insulators exhibit chiral dissipationless edge states without an external magnetic field, making them a promising material for quantum metrology and microwave applications. However, the breakdown of the…

Mesoscale and Nanoscale Physics · Physics 2025-05-30 Torsten Röper , Daniel Rosenbach , Achim Rosch , Alexey A. Taskin , Yoichi Ando , Erwann Bocquillon

The interplay between strong correlations and topology can lead to the emergence of intriguing quantum states of matter. One well-known example is the fractional quantum Hall effect, where exotic electron fluids with fractionally charged…

Finding guiding principles to optimize properties of quantum anomalous Hall (QAH) insulators is of pivotal importance to fundamental science and applications. Here, we build a first-principles QAH material database of chirality and band…

Materials Science · Physics 2023-01-18 Zhiming Xu , Wenhui Duan , Yong Xu

We show that the quantum anomalous Hall effect almost always occurs in magnetic topological insulator thin films whenever the top and bottom surface layer magnetizations are parallel, independent of the interior layer magnetization…

Mesoscale and Nanoscale Physics · Physics 2022-12-07 Chao Lei , Olle Heinonen , R. J. McQueeney , A. H. MacDonald

The search for topologically non-trivial states of matter has become an important goal for condensed matter physics. Recently, a new class of topological insulators has been proposed. These topological insulators have an insulating gap in…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Markus Koenig , Hartmut Buhmann , Laurens W. Molenkamp , Taylor L. Hughes , Chao-Xing Liu , Xiao-Liang Qi , Shou-Cheng Zhang

Combining tight-binding models and first principles calculations, we investigate the quantum anomalous Hall (QAH) effect induced by intrinsic spin-orbit coupling (SOC) in buckled honeycomb lattice with sp orbitals in an external exchange…

Mesoscale and Nanoscale Physics · Physics 2013-08-22 Hongbin Zhang , Frank Freimuth , Gustav Bihlmayer , Marjana Ležaić , Stefan Blügel , Yuriy Mokrousov

The Berry phase picture provides important insights into the electronic properties of condensed matter systems. The intrinsic anomalous Hall (AH) effect can be understood as a consequence of non-zero Berry curvature in momentum space. The…

We theoretically investigate the manipulation of the quantum anomalous Hall effect (QAHE) in graphene by means of the uniaxial strain. The values of Chern number and Hall conductance demonstrate that the strained graphene in presence of…

Mesoscale and Nanoscale Physics · Physics 2014-01-07 G. S. Diniz , M. R. Guassi , F. Qu