Haag duality for Kitaev's quantum double model for abelian groups

L Fiedler, P Naaijkens - Reviews in Mathematical Physics, 2015 - World Scientific
We prove Haag duality for cone-like regions in the ground state representation
corresponding to the translational invariant ground state of Kitaev's quantum double model …

On the stability of charges in infinite quantum spin systems

M Cha, P Naaijkens, B Nachtergaele - Communications in Mathematical …, 2020 - Springer
We consider a theory of superselection sectors for infinite quantum spin systems, describing
charges that can be approximately localized in cone-like regions. The primary examples we …

On Landauer's principle and bound for infinite systems

R Longo - Communications in Mathematical Physics, 2018 - Springer
Landauer's principle provides a link between Shannon's information entropy and Clausius'
thermodynamical entropy. Here we set up a basic formula for the incremental free energy of …

Boundary states of a bulk gapped ground state in 2-d quantum spin systems

Y Ogata - Communications in Mathematical Physics, 2024 - Springer
We introduce a natural mathematical definition of boundary states of a bulk gapped ground
state in the operator algebraic framework of 2-D quantum spin systems. With the …

An operator algebraic approach to symmetry defects and fractionalization

K Kawagoe, S Vadnerkar, D Wallick - arxiv preprint arxiv:2410.23380, 2024 - arxiv.org
We provide a superselection theory of symmetry defects in 2+ 1D symmetry enriched
topological (SET) order in the infinite volume setting. For a finite symmetry group $ G $ with a …

On gapped phases with a continuous symmetry and boundary operators

S Bachmann, B Nachtergaele - Journal of Statistical Physics, 2014 - Springer
We discuss the role of compact symmetry groups, G, in the classification of gapped ground
state phases of quantum spin systems. We consider two representations of G on infinite …

Superselection sectors for posets of von Neumann algebras

A Bhardwaj, T Brisky, CY Chuah, K Kawagoe… - arxiv preprint arxiv …, 2024 - arxiv.org
We study a commutant-closed collection of von Neumann algebras acting on a common
Hilbert space indexed by a poset with an order-reversing involution. We give simple …

The split and approximate split property in 2D systems: stability and absence of superselection sectors

P Naaijkens, Y Ogata - Communications in Mathematical Physics, 2022 - Springer
The split property of a pure state for a certain cut of a quantum spin system can be
understood as the entanglement between the two subsystems being weak. From this point of …

An algebraic quantum field theoretic approach to toric code with gapped boundary

D Wallick - Journal of Mathematical Physics, 2023 - pubs.aip.org
Topologically ordered quantum spin systems have become an area of great interest, as they
may provide a fault-tolerant means of quantum computation. One of the simplest examples …

Kitaev's quantum double model from a local quantum physics point of view

P Naaijkens - Advances in algebraic quantum field theory, 2015 - Springer
A prominent example of a topologically ordered system is Kitaev's quantum double model D
(G) for finite groups G (which in particular includes G= Z _2, the toric code). We will look at …