3 papers
math-ph2026
A note on invariants of mixed-state topological order in 2D
Yoshiko Ogata
The classification of mixed-state topological order requires indices that behave monotonically under finite-depth quantum channels. In two dimensions, a braided -tensor catego…
math-ph2025
Haag Duality for 2D Quantum Spin Systems
Yoshiko Ogata, David Pérez-GarcÃa, Alberto Ruiz-de-Alarcón
Haag duality is a fundamental locality property introduced in the pioneering formulation of algebraic quantum field theory by Haag and Kastler in the 1960s. Since then, it has play…
math-ph2025
Mixed state topological order: operator algebraic approach
Yoshiko Ogata
We study the classification problem of mixed states in two-dimensional quantum spin systems in the operator algebraic framework of quantum statistical mechanics. We associate a bra…