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Related papers: Topological Spin Texture in a Quantum Anomalous Ha…

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The quantum anomalous Hall (QAH) effect is conventionally understood to exist only in Chern insulators, while a recent study has shown that ferromagnetic metals can also host the QAH effect. Between insulators and metals, we demonstrate…

Mesoscale and Nanoscale Physics · Physics 2026-05-28 Peng-Yi Liu , Yu-Hao Wan , Qing-Feng Sun

In the quantum anomalous Hall (QAH) effect, chiral edge states are present in the absence of magnetic fields due to the intrinsic band topology. In this work, we predict that a synthesized two-dimensional metal-organic material, a…

Strongly Correlated Electrons · Physics 2023-06-09 Xiang-Long Yu , Tengfei Cao , Rui Wang , Ya-Min Quan , Jiansheng Wu

Quantum anomalous Hall (QAH) effect in the films with nontrivial band structure accompanies the ferromagnetic transition in the system of magnetic dopants. Experimentally, the QAH transition manifests itself as a jump in the dependence of…

Mesoscale and Nanoscale Physics · Physics 2016-09-21 Z. Yue , M. E. Raikh

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

The quantum spin Hall (QSH) state is a topologically non-trivial state of quantum matter which preserves time-reversal symmetry; it has an energy gap in the bulk, but topologically robust gapless states at the edge. Recently, this novel…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Chaoxing Liu , Taylor L. Hughes , Xiao-Liang Qi , Kang Wang , Shou-Cheng Zhang

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

Physical phenomena driven by topological properties, such as the quantum Hall effect, have the appealing feature to be robust with respect to external perturbations. Lately, a new class of materials has emerged manifesting their topological…

Mesoscale and Nanoscale Physics · Physics 2011-02-17 D. Bercioux , N. Goldman , D. F. Urban

Recent experimental progress in condensed matter physics enables the observation of signatures of the parity anomaly in two-dimensional Dirac-like materials. Using effective field theories and analyzing band structures in external…

Mesoscale and Nanoscale Physics · Physics 2020-08-13 J. Böttcher , C. Tutschku , L. W. Molenkamp , E. M. Hankiewicz

In quantum anomalous Hall (QAH) insulators, the interior is insulating but electrons can travel with zero resistance along one-dimensional conducting paths known as chiral edge channels (CECs). These CECs have been predicted to be confined…

Topological states of quantum matter have inspired both fascinating physics findings and exciting opportunities for applications. Due to the over-complicated structure of, as well as interactions between, real materials, a faithful quantum…

Quantum Physics · Physics 2021-04-19 Jia Liu , Jun-Yi Cao , Gang Chen , Zheng-Yuan Xue

In this Communication, we investigate a toy model of three-dimensional topological insulator surface, coupled homogeneously to a fictitious pseudo spin-$\frac{1}{2}$ particle. We show that this toy model captures the interesting features of…

Mesoscale and Nanoscale Physics · Physics 2015-07-01 S. A. Owerre , J. Nsofini

The quantum anomalous Hall (QAH) effect has been demonstrated in two-dimensional topological insulator systems incorporated with ferromagnetism. However, a comprehensive understanding of mesoscopic transport in sub-micron QAH devices has…

Mesoscale and Nanoscale Physics · Physics 2022-06-08 Gang Qiu , Peng Zhang , Peng Deng , Su Kong Chong , Lixuan Tai , Christopher Eckberg , Kang L. Wang

The quantum anomalous Hall effect (QAHE), the last member of Hall family, was predicted to exhibit quantized Hall conductivity e2/h without any external magnetic field. The QAHE shares a similar physical phenomenon with the integer quantum…

Mesoscale and Nanoscale Physics · Physics 2016-03-23 Cui-Zu Chang , Mingda Li

The search for new large band gap quantum spin Hall (QSH) and quantum anomalous Hall (QAH) insulators is critical for their realistic applications at room temperature. Here we predict, based on first principles calculations, that the band…

Mesoscale and Nanoscale Physics · Physics 2015-06-23 Chengwang Niu , Gustav Bihlmayer , Hongbin Zhang , Daniel Wortmann , Stefan Blugel , Yuriy Mokrousov

A Quantum Spin-Hall Insulator (QSHI) is implemented into a simple mass-spring Kagome lattice. The transition from the trivial state to the topological one is described by an invariant Chern number function of a contrast parameter. The band…

Mesoscale and Nanoscale Physics · Physics 2018-09-26 Hui Chen , Hussein Nassar , Andrew N. Norris , Gengkai Hu , Guoliang Huang

Topological insulators represent a new quantum state of matter that are insulating in the bulk but metallic on the edge or surface. In the Dirac surface state, it is well-established that the electron spin is locked with the crystal…

Recent theory predicted that the Quantum Spin Hall Effect, a fundamentally novel quantum state of matter that exists at zero external magnetic field, may be realized in HgTe/(Hg,Cd)Te quantum wells. We have fabricated such sample structures…

Quantum spin Hall (QSH) materials are two-dimensional systems exhibiting insulating bulk and helical edge states simultaneously. A QSH insulator processes topologically non-trivial edge states protected by time-reversal symmetry, so that…

Electron correlation and topology are two central threads of modern condensed matter physics. Semiconductor moir\'e materials provide a highly tunable platform for studies of electron correlation. Correlation-driven phenomena, including the…

Mesoscale and Nanoscale Physics · Physics 2021-12-28 Tingxin Li , Shengwei Jiang , Bowen Shen , Yang Zhang , Lizhong Li , Trithep Devakul , Kenji Watanabe , Takashi Taniguchi , Liang Fu , Jie Shan , Kin Fai Mak

As a topological insulator, the quantum Hall (QH) effect is indexed by the Chern and spin-Chern numbers $\mathcal{C}$ and $\mathcal{C}_{\text{spin}}$. We have only $\mathcal{C}_{\text{spin}}=0$ or $\pm \frac{1}{2}$ in conventional QH…

Mesoscale and Nanoscale Physics · Physics 2013-12-11 Motohiko Ezawa