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Related papers: Disordered Topological Insulators: A Non-Commutati…

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The high-Chern number phases with a Chern number C>1 have been observed in a recent experiment that performed on the topological insulator (TI) multilayer structures, consisting of the alternating magnetic-doped and undoped TI layers. In…

Mesoscale and Nanoscale Physics · Physics 2021-07-13 Yi-Xiang Wang , Fuxiang Li

We establish the theory of critical transport in amorphous Chern insulators and show that it lies beyond the current paradigm of topological criticality epitomized by the quantum Hall transitions. We consider models of Chern insulators on…

Mesoscale and Nanoscale Physics · Physics 2020-12-08 Moein N. Ivaki , Isac Sahlberg , Teemu Ojanen

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 fractional quantum Hall effect has recently been shown to exist in heterostructures of van der Waals materials without an externally applied magnetic field, e.g. in twisted bilayers of MoTe$_2$. These fractional Chern insulators break…

Strongly Correlated Electrons · Physics 2025-09-23 Sahana Das , Glenn Wagner , Titus Neupert

Protected by the chiral symmetry, three dimensional chiral topological insulators are characterized by an integer-valued topological invariant. How this invariant could emerge in physical observables is an important question. Here we show…

Mesoscale and Nanoscale Physics · Physics 2015-01-08 Sheng-Tao Wang , Dong-Ling Deng , Joel E. Moore , Kai Sun , Lu-Ming Duan

We relate the collective dynamic internal geometric degrees of freedom to the gauge fluctuations in $\nu=1/m$(m odd) fractional quantum Hall effects. In this way, in the lowest Landau level, a highly nontrivial quantum geometry in…

Strongly Correlated Electrons · Physics 2016-06-15 Xi Luo , Yong-Shi Wu , Yue Yu

A semimagnetic topological insulator -- a heterostructure combining a topological insulator with a ferromagnet -- exhibits a half-quantized Hall effect, characterized by a quantized Hall conductance of $\frac{1}{2}\frac{e^{2}}{h}$ (where…

Disordered Systems and Neural Networks · Physics 2025-10-30 Shi-Hao Bi , Bo Fu , Shun-Qing Shen

The robustness of the anomalous Hall conductance, $\sigma_{yx}^{}= \sigma_{H}^{}$, quantization in the model of a~two-dimensional disordered gas of massive Dirac electrons subjected to an external orthogonal magnetic field is investigated…

Mesoscale and Nanoscale Physics · Physics 2021-04-09 S. G. Novokshonov

We define topological invariants in terms of the ground states wave functions on a torus. This approach leads to precisely defined formulas for the Hall conductance in four dimensions and the topological magneto-electric $\theta$ term in…

Strongly Correlated Electrons · Physics 2014-01-28 Zhong Wang , Shou-Cheng Zhang

This pedagogical piece provides a surprisingly simple demonstration that the quantized Hall conductivity of correlated insulators is given by the many-body Chern number, a topological invariant defined in the space of twisted boundary…

Mesoscale and Nanoscale Physics · Physics 2024-09-06 Nathan Goldman , Tomoki Ozawa

Two-dimensional Euler insulators are novel kind of systems that host multi-gap topological phases, quantified by a quantised first Euler number in their bulk. Recently, these phases have been experimentally realised in suitable…

Mesoscale and Nanoscale Physics · Physics 2024-11-25 Adrien Bouhon , Yan-Qing Zhu , Robert-Jan Slager , Giandomenico Palumbo

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

Nontrivial bulk topological invariants of quantum materials can leave their signatures on charge, thermal and spin transports. In two dimensions, their imprints can be experimentally measured from well-developed multiterminal Hall bar…

Mesoscale and Nanoscale Physics · Physics 2024-05-03 Sanjib Kumar Das , Bitan Roy

Chern insulator is a building block of many topological quantum matters, ranging from quantum spin Hall insulators to fractional Chern insulators. Here, we discuss a new type of insulator, which consists of two half filled ordinary Chern…

Mesoscale and Nanoscale Physics · Physics 2017-05-24 Li-Jun Lang , Shao-Liang Zhang , Qi Zhou

We report results of numerical studies of the integer quantum Hall effect in a tight binding model on a two-dimensional square lattice with non-interacting electrons, in the presence of a random potential as well as a uniform magnetic field…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Kun Yang , R. N. Bhatt

Topological invariants are a significant ingredient in the study of topological phases of matter that intertwines the supposedly contradicting concepts of bulk and boundary. The nature of the invariants differ depending on the dimension of…

Mesoscale and Nanoscale Physics · Physics 2023-11-28 Srijata Lahiri , Saurabh Basu

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…

A topologically ordered material is characterized by a rare quantum organization of electrons that evades the conventional spontaneously broken symmetry based classification of condensed matter. Exotic spin transport phenomena such as the…

Mesoscale and Nanoscale Physics · Physics 2009-10-08 D. Hsieh , Y. Xia , L. Wray , D. Qian , A. Pal , J. H. Dil , F. Meier , J. Osterwalder , G. Bihlmayer , C. L. Kane , Y. S. Hor , R. J. Cava , M. Z. Hasan

We show that certain three-dimensional multigap topological insulators can host quantized integrated shift photoconductivities due to bulk invariants that are defined under reality conditions imposed by additional symmetries. We recast the…

Mesoscale and Nanoscale Physics · Physics 2024-10-30 Wojciech J. Jankowski , Robert-Jan Slager

The recently introduced classification of two-dimensional insulators in terms of topological crystalline invariants has been applied so far to "obstructed" atomic insulators characterized by a mismatch between the centers of the electronic…