Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Forum of Mathematics Pi

An -valued index of symmetry-protected topological phases with on-site finite group symmetry for two-dimensional quantum spin systems

Yoshiko Ogata

Published Jan 1, 2021• 15 citations
Publisher

Abstract

Abstract We consider symmetry-protected topological phases with on-site finite groupGsymmetry $\beta $ for two-dimensional quantum spin systems. We show that they have $H^{3}(G,{\mathbb T})$ -valued invariant.

DOI
10.1017/fmp.2021.17

Related papers

A $H^{3}(G,{\mathbb T})$-valued index of symmetry protected topological phases with on-site finite group symmetry for two-dimensional quantum spin systems

Yoshiko Ogata

We consider SPT-phases with on-site finite group $G$ symmetry $β$ for two-dimensional quantum spin systems. We show that they have $H^{3}(G,{\mathbb T})$-valued invariant.

arXiv:2101.00426•Jan 2, 2021•6 citations

Classification of symmetry protected topological phases in quantum spin chains

Yoshiko Ogata

We consider the classification problem of symmetry protected topological (SPT) phases on quantum spin systems.SPT phases are gapped short-range-entangled quantum phases with a symmetry G.We explain that in one and two-dimensional quantum spin systems, there are H 2 (G, U (1))/ H 3 (G, U (1))-valued invariant, confirming a physicists conjecture.Contents 1. Symmetry protected topological phases 41 2. SPT-phases in 1-dimensional systems 63 3. SPT-phases in 2-dimensional systems 78

arXiv:2110.04671•Current Developments in Mathematics•Jan 1, 2020•15 citations

The classification of symmetry protected topological phases of one-dimensional fermion systems

Chris Bourne, Yoshiko Ogata

Abstract We introduce an index for symmetry-protected topological (SPT) phases of infinite fermionic chains with an on-site symmetry given by a finite group G. This index takes values in $\mathbb {Z}_2 \times H^1(G,\mathbb {Z}_2) \times H^2(G, U(1)_{\mathfrak {p}})$ with a generalised Wall group law under stacking. We show that this index is an invariant of the classification of SPT phases. When the ground state is translation invariant and has reduced density matrices with uniformly bounded rank on finite intervals, we derive a fermionic matrix product representative of this state with on-site symmetry.

arXiv:2006.15232•Forum of Mathematics Sigma•Jan 1, 2021•25 citations

Classification of symmetry protected states of quantum spin chains for continuous symmetry groups

Bruno de O. Carvalho, Wojciech De Roeck, Tijl Jappens

Symmetry protected states (SPT's) of quantum spin systems were studied by several authors. For one-dimensional systems (spin chains), there is an essentially complete and rigorous understanding: SPT's corresponding to finite on-site symmetry groups $G$ are classified by the second cohomology group $H^2(G,U(1))$, as established by Kapustin et al. [J. Math. Phys. (2021)]. We extend this result to the case of compact topological symmetry groups $G$. We also strengthen the existing results in the sense that our classification results holds within the class of spin chains with locally bounded on-site dimensions.

arXiv:2409.01112•Sep 2, 2024•0 citations

Classification of symmetry protected states of quantum spin chains for continuous symmetry groups

Bruno de O. Carvalho, Wojciech De Roeck, Tijl Jappens

Symmetry protected states (SPTs) of quantum spin systems were studied by several authors. For one-dimensional systems (spin chains), there is an essentially complete and rigorous understanding: SPTs corresponding to finite on-site symmetry groups G are classified by the second cohomology group H2(G, U(1)), as established in Kapustin, Sopenko, and Yang. J. Math. Phys. 62(8), 081901 (2021). We extend this result to the case of compact and metrizable topological symmetry groups G. We also strengthen the existing results in the sense that our classification results hold within the class of spin chains with locally bounded on-site dimensions.

Journal of Mathematical Physics•Jul 1, 2025•0 citations

An index for two-dimensional SPT states

Nikita Sopenko

We define an index for 2D G-invariant invertible states of bosonic lattice systems in the thermodynamic limit for a finite symmetry group G with a unitary action. We show that this index is an invariant of the symmetry protected phase.

arXiv:2101.00801•Journal of Mathematical Physics•Nov 1, 2021•13 citations
Abstract We consider symmetry-protected topological phases with on-site finite groupGsymmetry β\beta β for two-dimensional quantum spin systems. We show that they have H3(G,T)H^{3}(G,{\mathbb T})H3(G,T) -valued invariant.
A H3(G,T)H^{3}(G,{\mathbb T})H3(G,T)-valued index of symmetry protected topological phases with on-site finite group symmetry for two-dimensional quantum spin systems
We consider SPT-phases with on-site finite group GGG symmetry βββ for two-dimensional quantum spin systems. We show that they have H3(G,T)H^{3}(G,{\mathbb T})H3(G,T)-valued invariant.
Abstract We introduce an index for symmetry-protected topological (SPT) phases of infinite fermionic chains with an on-site symmetry given by a finite group G. This index takes values in Z2×H1(G,Z2)×H2(G,U(1)p)\mathbb {Z}_2 \times H^1(G,\mathbb {Z}_2) \times H^2(G, U(1)_{\mathfrak {p}})Z2​×H1(G,Z2​)×H2(G,U(1)p​) with a generalised Wall group law under stacking. We show that this index is an invariant of the classification of SPT phases. When the ground state is translation invariant and has reduced density matrices with uniformly bounded rank on finite intervals, we derive a fermionic matrix product representative of this state with on-site symmetry.
Symmetry protected states (SPT's) of quantum spin systems were studied by several authors. For one-dimensional systems (spin chains), there is an essentially complete and rigorous understanding: SPT's corresponding to finite on-site symmetry groups GGG are classified by the second cohomology group H2(G,U(1))H^2(G,U(1))H2(G,U(1)), as established by Kapustin et al. [J. Math. Phys. (2021)]. We extend this result to the case of compact topological symmetry groups GGG. We also strengthen the existing results in the sense that our classification results holds within the class of spin chains with locally bounded on-site dimensions.
Symmetry protected states (SPTs) of quantum spin systems were studied by several authors. For one-dimensional systems (spin chains), there is an essentially complete and rigorous understanding: SPTs corresponding to finite on-site symmetry groups G are classified by the second cohomology group H2(G, U(1)), as established in Kapustin, Sopenko, and Yang. J. Math. Phys. 62(8), 081901 (2021). We extend this result to the case of compact and metrizable topological symmetry groups G. We also strengthen the existing results in the sense that our classification results hold within the class of spin chains with locally bounded on-site dimensions.