A non-commutative framework for topological insulators

C Bourne, AL Carey, A Rennie - Reviews in Mathematical Physics, 2016 - World Scientific
We study topological insulators, regarded as physical systems giving rise to topological
invariants determined by symmetries both linear and anti-linear. Our perspective is that of …

Wannier functions and invariants in time-reversal symmetric topological insulators

HD Cornean, D Monaco, S Teufel - Reviews in Mathematical …, 2017 - World Scientific
We provide a constructive proof of exponentially localized Wannier functions and related
Bloch frames in 1-and 2-dimensional time-reversal symmetric (TRS) topological insulators …

The K-Theoretic Bulk–Edge Correspondence for Topological Insulators

C Bourne, J Kellendonk, A Rennie - Annales Henri Poincaré, 2017 - Springer
We study the application of Kasparov theory to topological insulator systems and the bulk–
edge correspondence. We consider observable algebras as modelled by crossed products …

The topological classification of one-dimensional symmetric quantum walks

C Cedzich, T Geib, FA Grünbaum, C Stahl… - Annales Henri …, 2018 - Springer
We give a topological classification of quantum walks on an infinite 1D lattice, which obey
one of the discrete symmetry groups of the tenfold way, have a gap around some …

Index pairings in presence of symmetries with applications to topological insulators

J Großmann, H Schulz-Baldes - Communications in Mathematical Physics, 2016 - Springer
In a basic framework of a complex Hilbert space equipped with a complex conjugation and
an involution, linear operators can be real, quaternionic, symmetric or anti-symmetric, and …

The noncommutative index theorem and the periodic table for disordered topological insulators and superconductors

H Katsura, T Koma - Journal of Mathematical Physics, 2018 - pubs.aip.org
We study a wide class of topological free-fermion systems on a hypercubic lattice in spatial
dimensions d≥ 1. When the Fermi level lies in a spectral gap or a mobility gap, the …

Complete homotopy invariants for translation invariant symmetric quantum walks on a chain

C Cedzich, T Geib, C Stahl, L Velázquez… - Quantum, 2018 - quantum-journal.org
We provide a classification of translation invariant one-dimensional quantum walks with
respect to continuous deformations preserving unitarity, locality, translation invariance, a …

Skew localizer and Z2-flows for real index pairings

N Doll, H Schulz-Baldes - Advances in Mathematics, 2021 - Elsevier
Real index pairings of projections and unitaries on a separable Hilbert space with a real
structure are defined when the projections and unitaries fulfill symmetry relations invoking …

The ℤ2 index of disordered topological insulators with time reversal symmetry

H Katsura, T Koma - Journal of Mathematical Physics, 2016 - pubs.aip.org
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 …

Chern numbers, localisation and the bulk-edge correspondence for continuous models of topological phases

C Bourne, A Rennie - Mathematical Physics, Analysis and Geometry, 2018 - Springer
In order to study continuous models of disordered topological phases, we construct an
unbounded Kasparov module and a semifinite spectral triple for the crossed product of a …