English
Related papers

Related papers: K-Theory and Pseudospectra for Topological Insulat…

200 papers

We describe Universal Coefficient Theorems for the equivariant Kasparov theory for C*-algebras with an action of the group of integers or over a unique path space, using KK-valued invariants. We compare the resulting classification up to…

K-Theory and Homology · Mathematics 2020-11-04 Ralf Meyer

Topological classification in our previous paper [K. Shiozaki and M. Sato, Phys. Rev. B ${\bf 90}$, 165114 (2014)] is extended to nonsymmorphic crystalline insulators and superconductors. Using the twisted equivariant $K$-theory, we…

Mesoscale and Nanoscale Physics · Physics 2016-05-12 Ken Shiozaki , Masatoshi Sato , Kiyonori Gomi

Gapped phases of noninteracting fermions, with and without charge conservation and time-reversal symmetry, are classified using Bott periodicity. The symmetry and spatial dimension determines a general universality class, which corresponds…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 Alexei Kitaev

We present a systematic topological classification of fermionic and bosonic topological phases protected by time-reversal, particle-hole, parity, and combination of these symmetries. We use two complementary approaches: one in terms of…

Strongly Correlated Electrons · Physics 2015-06-19 Chang-Tse Hsieh , Takahiro Morimoto , Shinsei Ryu

We consider functors from the category of locally convex algebras to abelian groups and prove invariance under smooth homotopies for weakly J-stable algebras, where J is a harmonic operator ideal. This applies in particular to negative…

K-Theory and Homology · Mathematics 2007-05-23 Joachim Cuntz , Andreas Thom

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 propose a new method to numerically compute the $\mathbb{Z}_2$ indices for disordered topological insulators in Kitaev's periodic table. All of the $\mathbb{Z}_2$ indices are known to be derived from the index formulae which are…

Mesoscale and Nanoscale Physics · Physics 2017-12-13 Yutaka Akagi , Hosho Katsura , Tohru Koma

We show that the K-theory spectra of many assemblers, such as the assembler of polytopes in euclidean, hyperbolic or spherical geometry, as well as the assembler of definable sets, are equivalent to the K-theory spectrum of a squares…

K-Theory and Homology · Mathematics 2025-12-02 Josefien Kuijper

We find lower bounds on the rank of a "real" vector bundle over an involutive space, such that "real" vector bundles of higher rank have a trivial summand and such that a stable isomorphism for such bundles implies ordinary isomorphism. We…

K-Theory and Homology · Mathematics 2025-06-25 Malkhaz Bakuradze , Ralf Meyer

Nonlinear topological insulators have garnered substantial recent attention as they have both enabled the discovery of new physics due to interparticle interactions, and may have applications in photonic devices such as topological lasers…

Mesoscale and Nanoscale Physics · Physics 2023-11-30 Stephan Wong , Terry A. Loring , Alexander Cerjan

We use constructive bounded Kasparov K-theory to investigate the numerical invariants stemming from the internal Kasparov products $K_i(\mathcal A) \times KK^i(\mathcal A, \mathcal B) \rightarrow K_0(\mathcal B) \rightarrow \mathbb R$,…

Operator Algebras · Mathematics 2016-11-16 Emil Prodan , Hermann Schulz-Baldes

Building on the 10-way symmetry classification of disordered fermions, the authors have recently given a homotopy-theoretic proof of Kitaev's "Periodic Table" for topological insulators and superconductors. The present paper offers an…

Mathematical Physics · Physics 2016-02-24 R. Kennedy , M. R. Zirnbauer

Using a dimensional reduction scheme based on scattering theory, we show that the classification tables for topological insulators and superconductors with reflection symmetry can be organized in two period-two and four period-eight cycles,…

Mesoscale and Nanoscale Physics · Physics 2017-11-03 Luka Trifunovic , Piet Brouwer

We construct a new class of N-dimensional Lie algebras and apply them to integrable systems. In this paper, we obtain a nonisospectral KdV integrable hierarchy by introducing a nonisospectral spectral problem. Then, a coupled nonisospectral…

Mathematical Physics · Physics 2024-10-23 Haifeng Wang , Yufeng Zhang , Binlu Feng

In this paper, we introduce a variation of the notion of topological phase reflecting metric structure of the position space. This framework contains not only periodic and non-periodic systems with symmetries in Kitaev's periodic table but…

Mathematical Physics · Physics 2016-07-20 Yosuke Kubota

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

For inversion-symmetric topological insulators and superconductors characterized by ${\mathbb Z}_{2}$ topological invariants, two scaling schemes are proposed to judge topological phase transitions driven by an energy parameter. The scaling…

Mesoscale and Nanoscale Physics · Physics 2016-07-13 Wei Chen , Manfred Sigrist , Andreas P. Schnyder

The detection of topological phases of matter becomes a central issue in recent years. Conventionally, the realization of a specific topological phase in condensed matter physics relies on probing the underlying surface band dispersion or…

Quantum Physics · Physics 2020-09-02 Tao Xin , Yishan Li , Yu-ang Fan , Xuanran Zhu , Yingjie Zhang , Xinfang Nie , Jun Li , Qihang Liu , Dawei Lu

A family of discrete Schroedinger operators is investigated through scattering theory. The continuous spectrum of these operators exhibit changes of multiplicity, and some of these operators possess resonances at thresholds. It is shown…

Mathematical Physics · Physics 2024-03-27 V. Austen , D. Parra , A. Rennie , S. Richard

By analogy with algebraic geometry, we define a category of non-linear sheaves (quasi-coherent homotopy-sheaves of topological spaces) on projective toric varieties and prove a splitting result for its algebraic K-theory, generalising…

K-Theory and Homology · Mathematics 2010-07-30 Thomas Huettemann