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Related papers: A New Numerical Method for $\mathbb{Z}_2$ Topologi…

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We revisit the question of whether a two-dimensional topological insulator may arise in a commensurate N\'eel antiferromagnet, where staggered magnetization breaks both the elementary translation and time reversal, but retains their product…

Strongly Correlated Electrons · Physics 2016-04-07 Frédéric Bègue , Pierre Pujol , Revaz Ramazashvili

A global phase diagram of disordered weak and strong topological insulators is established numerically. As expected, the location of the phase boundaries is renormalized by disorder, a feature recognized in the study of the so-called…

Mesoscale and Nanoscale Physics · Physics 2013-06-14 Koji Kobayashi , Tomi Ohtsuki , Ken-Ichiro Imura

Taking the clue from the modern theory of polarization [R. Resta, Rev. Mod. Phys. {\bf 66}, 899 (1994)], we identify an operator to distinguish between ${\mathbb Z}_2$-even (trivial) and ${\mathbb Z}_2$-odd (topological) insulators in two…

Strongly Correlated Electrons · Physics 2022-12-01 Ivan Gilardoni , Federico Becca , Antimo Marrazzo , Alberto Parola

The intense theoretical and experimental interest in topological insulators and semimetals has established band structure topology as a fundamental material property. Consequently, identifying band topologies has become an important, but…

Electronic topological insulators are one of the breakthroughs of the 21st century condensed matter physics. So far, the search for a light counterpart of an electronic topological insulator has remained elusive. This is due to the…

Mesoscale and Nanoscale Physics · Physics 2016-02-05 Mario G. Silveirinha

We present a general description of topological insulators from the point of view of Dirac equations. The Z_{2} index for the Dirac equation is always zero, and thus the Dirac equation is topologically trivial. After the quadratic B term in…

Mesoscale and Nanoscale Physics · Physics 2012-06-20 Shun-Qing Shen , Wen-Yu Shan , Hai-Zhou Lu

Topological insulators are physically distinguishable from normal insulators only near edges and defects, while in the bulk there is no clear signature to their topological order. In this work we show that the Z index of topological…

Mesoscale and Nanoscale Physics · Physics 2011-06-24 Zohar Ringel , Yaacov E. Kraus

In this paper we give the full microscopic derivation of the model Hamiltonian for the three dimensional topological insulators in the $Bi_2Se_3$ family of materials ($Bi_2Se_3$, $Bi_2Te_3$ and $Sb_2Te_3$). We first give a physical picture…

Materials Science · Physics 2015-05-18 Chao-Xing Liu , Xiao-Liang Qi , HaiJun Zhang , Xi Dai , Zhong Fang , Shou-Cheng Zhang

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

The topological phases of two-dimensional time-reversal symmetric insulators are classified by a $\mathbb{Z}_{2}$ topological invariant. Usually, the invariant is introduced and calculated by exploiting the way time-reversal symmetry acts…

Mesoscale and Nanoscale Physics · Physics 2024-09-06 Nicolas Baù , Antimo Marrazzo

Topological insulator(TI) is a phase of matter discovered recently. Kane and Mele proposed this phase is distinguished from the ordinary band insulator by a Z2 topological invariant.2 Several authors have try to related this Z2 invariant to…

Materials Science · Physics 2011-03-01 Yidong Wu

The topology of electronic states in band insulators with mirror symmetry can be classified in two different ways. One is in terms of the mirror Chern number, an integer that counts the number of protected Dirac cones in the Brillouin zone…

Mesoscale and Nanoscale Physics · Physics 2021-05-10 Tomáš Rauch , Thomas Olsen , David Vanderbilt , Ivo Souza

We propose a definition of a ${\mathbb Z}_2$ topological invariant for magnon spin Hall systems which are the bosonic analog of two-dimensional topological insulators in class AII. The existence of "Kramers pairs" in these systems is…

Mesoscale and Nanoscale Physics · Physics 2020-10-07 Hiroki Kondo , Yutaka Akagi , Hosho Katsura

The theory of almost commuting matrices can be used to quantify topological obstructions to the existence of localized Wannier functions with time-reversal symmetry in systems with time-reversal symmetry and strong spin-orbit coupling. We…

Mesoscale and Nanoscale Physics · Physics 2015-05-19 T. A. Loring , M. B. Hastings

We apply ideas from $C^*$-algebra to the study of disordered topological insulators. We extract certain almost commuting matrices from the free Fermi Hamiltonian, describing band projected coordinate matrices. By considering topological…

Mesoscale and Nanoscale Physics · Physics 2012-01-18 M. B. Hastings , T. A. Loring

We define a $\mathbb{Z}_2$-valued topological and gauge invariant associated to any 1-dimensional, translation-invariant topological insulator which satisfies either particle-hole symmetry or chiral symmetry. The invariant can be computed…

Mathematical Physics · Physics 2023-05-01 Domenico Monaco , Gabriele Peluso

We have performed a computational screening of topological two-dimensional (2D) materials from the Computational 2D Materials Database (C2DB) employing density functional theory. A full \textit{ab initio} scheme for calculating hybrid…

The prediction of non-trivial topological phases in Bloch insulators in three dimensions has recently been experimentally verified. Here, I provide a picture for obtaining the $Z_{2}$ invariants for a three dimensional topological insulator…

Other Condensed Matter · Physics 2010-04-21 Rahul Roy

We study the effect of strong disorder in a 3-dimensional topological insulators with time-reversal symmetry and broken inversion symmetry. Firstly, using level statistics analysis, we demonstrate the persistence of delocalized bulk states…

Disordered Systems and Neural Networks · Physics 2012-07-02 Bryan Leung , Emil Prodan

In light of recent progress in the study of amorphous topological phases, we investigate the effects of structural disorder on the topological properties of a two-dimensional quantum spin Hall insulator modeled by the Bernevig-Hughes-Zhang…

Disordered Systems and Neural Networks · Physics 2025-10-28 Ranadeep Roy , Yuan-Ming Lu