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Topological crystalline phases in electronic structures can be generally classified using the spatial symmetry characters of the valence bands and mapping them onto appropriate symmetry indicators. These mappings have been recently applied…

Mesoscale and Nanoscale Physics · Physics 2019-10-02 Sander H. Kooi , Guido van Miert , Carmine Ortix

Axial vectors, such as current or magnetization, are commonly used order parameters in time-reversal symmetry breaking systems. These vectors also break isotropy in three dimensional systems, lowering the spatial symmetry. We demonstrate…

Mesoscale and Nanoscale Physics · Physics 2026-02-25 Helene Spring , Anton R. Akhmerov , Daniel Varjas

We study disordered topological insulators with time reversal symmetry. Relying on the noncommutative index theorem which relates the Chern number to the projection onto the Fermi sea and the magnetic flux operator, we give a precise…

Mathematical Physics · Physics 2016-03-03 Hosho Katsura , Tohru Koma

We study topological indices of Fermionic time-reversal invariant topological insulators in two dimensions, in the regime of strong Anderson localization. We devise a method to interpolate between certain Fredholm operators arising in the…

Mathematical Physics · Physics 2022-11-30 Alex Bols , Jeffrey Schenker , Jacob Shapiro

Two-dimensional 2-bands insulators breaking time reversal symmetry can present topological phases indexed by a topological invariant called the Chern number. Here we first propose an efficient procedure to determine this topological index.…

Mesoscale and Nanoscale Physics · Physics 2012-05-28 Doru Sticlet , Frederic Piéchon , Jean-Noël Fuchs , Pavel Kalugin , Pascal Simon

Solid state systems with time reversal symmetry and/or particle-hole symmetry often only have $\mathbb{Z}_2$-valued strong invariants for which no general local formula is known. For physically relevant values of the parameters, there may…

Mathematical Physics · Physics 2020-08-26 Nora Doll , Hermann Schulz-Baldes

Real topological phases protected by the spacetime inversion (P T) symmetry are a current research focus. The basis is that the P T symmetry endows a real structure in momentum space, which leads to Z2 topological classifications in 1D and…

Mesoscale and Nanoscale Physics · Physics 2024-04-17 S. J. Yue , Qing Liu , Shengyuan A. Yang , Y. X. Zhao

In theory of topological classification, the 2D topological superconductors without time reversal symmetry are characterized by Chern numbers. However, in reality, we find the Chern numbers can not reveal the whole properties of the…

Superconductivity · Physics 2022-03-04 Jinpeng Xiao , Qianglin Hu , Huiqiong Zeng , Xiaobing Luo

The topology of insulators is usually revealed through the presence of gapless boundary modes: this is the so-called bulk-boundary correspondence. However, the many-body wavefunction of a crystalline insulator is endowed with additional…

Mesoscale and Nanoscale Physics · Physics 2021-01-08 Sander H. Kooi , Guido van Miert , Carmine Ortix

Symmetries play an essential role in identifying and characterizing topological states of matter. Here, we classify topologically two-dimensional (2D) insulators and semimetals with vanishing spin-orbit coupling using time-reversal…

Mesoscale and Nanoscale Physics · Physics 2016-12-14 Guido van Miert , Carmine Ortix , Cristiane Morais Smith

We construct a set of lattice models of non-interacting topological insulators with chiral symmetry in three dimensions. We build a model of the topological insulators in the class AIII by coupling lower dimensional models of $\mathbb{Z}$…

Mesoscale and Nanoscale Physics · Physics 2023-08-09 Donghao Liu , Polina Matveeva , Dmitri Gutman , Sam T. Carr

Topological insulators, along with Chern insulators and Quantum Hall insulator phases, are considered as paradigms for symmetry protected topological phases of matter. This article reports the experimental realization of the time-reversal…

Mesoscale and Nanoscale Physics · Physics 2021-01-01 Priya Tiwari , Saurabh Kumar Srivastav , Sujay Ray , Tanmoy Das , Aveek Bid

We define a new $Z_2$-valued index to characterize the topological properties of periodically driven two dimensional crystals when the time-reversal symmetry is enforced. This index is associated with a spectral gap of the evolution…

Mesoscale and Nanoscale Physics · Physics 2015-03-24 David Carpentier , Pierre Delplace , Michel Fruchart , Krzysztof Gawędzki

Based on previous results of digital topology, this paper focuses on algorithms of topological invariants of objects in 2D and 3D Digital Spaces. We specifically interest in solving hole counting of 2D objects and genus of closed surface in…

Computational Geometry · Computer Science 2013-09-18 Li Chen

We study the topological band theory of time reversal invariant topological insulators and interpret the topological $\mathbb{Z}_2$ invariant as an obstruction in terms of Stiefel--Whitney classes. The band structure of a topological…

Mathematical Physics · Physics 2016-04-12 Ralph M. Kaufmann , Dan Li , Birgit Wehefritz-Kaufmann

Inspired by a recently constructed commuting-projector Hamiltonian for a two-dimensional (2D) time-reversal-invariant topological superconductor [Wang et al., Phys. Rev. B 98, 094502 (2018)], we introduce a commuting-projector model that…

Strongly Correlated Electrons · Physics 2019-10-09 Jun Ho Son , Jason Alicea

In this work we consider whether nonsymmorphic symmetries such as a glide plane can protect the existence of topological crystalline insulators and superconductors in three dimensions. In analogy to time-reversal symmetric insulators, we…

Strongly Correlated Electrons · Physics 2015-11-11 Daniel Varjas , Fernando de Juan , Yuan-Ming Lu

We propose an alternative formulation of the $Z_2$ topological index for quantum spin Hall systems and band insulators when time reversal invariance is not broken. The index is expressed in terms of the Chern numbers of the bands of the…

Mesoscale and Nanoscale Physics · Physics 2009-11-01 Rahul Roy

We extend the previously defined many-body marker for two-dimensional $\mathbb{Z}_2$ topological insulators [I. Gilardoni {\it et al.}, Phys. Rev. B {\bf 106}, L161106 (2022)] to distinguish trivial, weak-, and strong-topological insulators…

Strongly Correlated Electrons · Physics 2025-08-06 Federico Becca , Alberto Parola

We propose general topological order parameters for interacting insulators in terms of the Green's function at zero frequency. They provide an unified description of various interacting topological insulators including the quantum anomalous…

Strongly Correlated Electrons · Physics 2012-08-15 Zhong Wang , Shou-Cheng Zhang