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Related papers: On the average spin Chern number

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Fractionally charged elementary excitations, the quasi-electron and quasi-hole, are one of the hallmarks of the fractional Chern insulator (FCI). In this work, we observe that spontaneous spin polarization in twisted MoTe$_2$ leads to…

We prove a general theorem on the relation between the bulk topological quantum number and the edge states in two dimensional insulators. It is shown that whenever there is a topological order in bulk, characterized by a non-vanishing Chern…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Xiao-Liang Qi , Yong-Shi Wu , Shou-Cheng Zhang

A central property of Chern insulators is the robustness of the topological phase and edge states to impurities in the system. Despite this, Chern number cannot be straightforwardly calculated in the presence of disorder. Recently, work has…

Strongly Correlated Electrons · Physics 2022-10-20 Peru d'Ornellas , Ryan Barnett , Derek K. K. Lee

The spin Hall conductivity (SHC) and anomalous Hall conductivity (AHC) in more than 120 full Heusler compounds are calculated using density functional theory in a high-throughtput way. The electronic structures are mapped to the Wannier…

Materials Science · Physics 2022-05-25 Yimin Ji , Wenxu Zhang , Hongbin Zhang , Wanli Zhang

Topological invariants in the band structure, such as Chern numbers, are crucial for the classification of topological matters and dictate the occurrence of exotic properties, yet their direct spectroscopic determination has been largely…

We introduce two dimensional fermionic band models with two orbitals per lattice site, or one spinful orbital, and which have a non-zero topological Chern number that can be changed by varying the ratio of hopping parameters. A…

Strongly Correlated Electrons · Physics 2013-02-14 Miguel A. N. Araújo , Eduardo V. Castro , Pedro D. Sacramento

Quantum spin Hall insulators hosting edge spin currents hold great potential for low-power spintronic devices. In this paper, we present a universal approach to achieve a high and near-quantized spin Hall conductance plateau within a…

Materials Science · Physics 2024-10-16 Lu Liu , Yuntian Liu , Jiayu Li , Hua Wu , Qihang Liu

This paper is a survey of the $\mathbb{Z}_2$-valued invariant of topological insulators used in condensed matter physics. The $\mathbb{Z}$-valued topological invariant, which was originally called the TKNN invariant in physics, has now been…

Mathematical Physics · Physics 2016-12-28 Ralph M. Kaufmann , Dan Li , Birgit Wehefritz-Kaufmann

We investigate a new class of topological antiferromagnetic (AF) Chern insulators driven by electronic interactions in two-dimensional systems without inversion symmetry. Despite the absence of a net magnetization, AF Chern insulators…

Strongly Correlated Electrons · Physics 2018-04-17 Kun Jiang , Sen Zhou , Xi Dai , Ziqiang Wang

Chern insulators are periodic band insulators with the property that their projector onto the occupied bands have non-zero Chern number. Chern insulator with a homogeneous boundary display continuum spectrum that fills the entire insulating…

Mesoscale and Nanoscale Physics · Physics 2009-08-24 Emil Prodan

A family of semiconductors called as Chern band insulator are shown to host exciton bands with non-zero topological Chern integers and chiral exciton edge modes. Using a prototypical two-band Chern insulator model, we calculate a…

Mesoscale and Nanoscale Physics · Physics 2017-10-11 Ke Chen , Ryuichi Shindou

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

Topological frequency converters exploit a quantized transfer of power between two driving fields in a quantum system, a phenomenon topologically protected by the Chern number of the associated fiber bundle. While realizations with few-spin…

Strongly Correlated Electrons · Physics 2026-04-29 Anshuman Tripathi , Mircea Trif , Thore Posske

We present measurements of a topological property, the Chern number ($C_\mathrm{1}$), of a closed manifold in the space of two-level system Hamiltonians, where the two-level system is formed from a superconducting qubit. We manipulate the…

Chern insulators are band insulators exhibiting a nonzero Hall conductance but preserving the lattice translational symmetry. We conclusively show that a partially filled Chern insulator at 1/3 filling exhibits a fractional quantum Hall…

Strongly Correlated Electrons · Physics 2015-03-19 N. Regnault , B. Andrei Bernevig

The study of topology of energy bands in solid has always been interesting and fruitful. Historically, Thouless et al proposed the TKNN number or Chern number of the energy bands to explain the quantization of Hall conductance in the…

Materials Science · Physics 2012-01-09 Yi-Dong Wu

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

Generally, stacking two monolayer type-I quantum spin Hall insulators gives rise to a trivial insulator. However, whether or not stacking two type-II quantum spin Hall insulators results in a trivial insulator has not yet been explored. In…

Mesoscale and Nanoscale Physics · Physics 2025-08-08 Chao-Yang Tan , Panjun Feng , Ze-Feng Gao , Fengjie Ma , Peng-Jie Guo , Zhong-Yi Lu

Starting from a minimal model for a 2D nodal loop semimetal, we study the effect of chiral mass gap terms. The resulting Dirac loop anomalous Hall insulator's Chern number is the phase winding number of the mass gap terms on the loop. We…

Mesoscale and Nanoscale Physics · Physics 2016-10-19 Linhu Li , Miguel A. N. Araújo

Chern insulators, which are the lattice analogs of the quantum Hall states, can potentially manifest high-temperature topological orders at zero magnetic field to enable next-generation topological quantum devices. To date, integer Chern…