Strong-to-weak spontaneous breaking of 1-form symmetry and intrinsically mixed topological order

Fuente: arXiv
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Main Authors: Zhang, Carolyn, Xu, Yichen, Zhang, Jian-Hao, Xu, Cenke, Bi, Zhen, Luo, Zhu-Xi
Format: Preprint
Published: 2024
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author Zhang, Carolyn
Xu, Yichen
Zhang, Jian-Hao
Xu, Cenke
Bi, Zhen
Luo, Zhu-Xi
author_facet Zhang, Carolyn
Xu, Yichen
Zhang, Jian-Hao
Xu, Cenke
Bi, Zhen
Luo, Zhu-Xi
contents Topological orders in 2+1d are spontaneous symmetry-breaking (SSB) phases of 1-form symmetries in pure states. The notion of symmetry is further enriched in the context of mixed states, where a symmetry can be either ``strong" or ``weak". In this work, we apply a Rényi-2 version of the proposed equivalence relation in [Sang, Lessa, Mong, Grover, Wang, & Hsieh, to appear] on density matrices that is slightly finer than two-way channel connectivity. This equivalence relation distinguishes general 1-form strong-to-weak SSB (SW-SSB) states from phases containing pure states, and therefore labels SW-SSB states as ``intrinsically mixed". According to our equivalence relation, two states are equivalent if and only if they are connected to each other by finite Lindbladian evolution that maintains continuously varying, finite Rényi-2 Markov length. We then examine a natural setting for finding such density matrices: disordered ensembles. Specifically, we study the toric code with various types of disorders and show that in each case, the ensemble of ground states corresponding to different disorder realizations form a density matrix with different strong and weak SSB patterns of 1-form symmetries, including SW-SSB. Furthermore we show by perturbative calculations that these disordered ensembles form stable ``phases" in the sense that they exist over a finite parameter range, according to our equivalence relation.
format Preprint
id arxiv_https___arxiv_org_abs_2409_17530
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Strong-to-weak spontaneous breaking of 1-form symmetry and intrinsically mixed topological order
Zhang, Carolyn
Xu, Yichen
Zhang, Jian-Hao
Xu, Cenke
Bi, Zhen
Luo, Zhu-Xi
Quantum Physics
Disordered Systems and Neural Networks
Statistical Mechanics
Strongly Correlated Electrons
High Energy Physics - Theory
Topological orders in 2+1d are spontaneous symmetry-breaking (SSB) phases of 1-form symmetries in pure states. The notion of symmetry is further enriched in the context of mixed states, where a symmetry can be either ``strong" or ``weak". In this work, we apply a Rényi-2 version of the proposed equivalence relation in [Sang, Lessa, Mong, Grover, Wang, & Hsieh, to appear] on density matrices that is slightly finer than two-way channel connectivity. This equivalence relation distinguishes general 1-form strong-to-weak SSB (SW-SSB) states from phases containing pure states, and therefore labels SW-SSB states as ``intrinsically mixed". According to our equivalence relation, two states are equivalent if and only if they are connected to each other by finite Lindbladian evolution that maintains continuously varying, finite Rényi-2 Markov length. We then examine a natural setting for finding such density matrices: disordered ensembles. Specifically, we study the toric code with various types of disorders and show that in each case, the ensemble of ground states corresponding to different disorder realizations form a density matrix with different strong and weak SSB patterns of 1-form symmetries, including SW-SSB. Furthermore we show by perturbative calculations that these disordered ensembles form stable ``phases" in the sense that they exist over a finite parameter range, according to our equivalence relation.
title Strong-to-weak spontaneous breaking of 1-form symmetry and intrinsically mixed topological order
topic Quantum Physics
Disordered Systems and Neural Networks
Statistical Mechanics
Strongly Correlated Electrons
High Energy Physics - Theory
url https://arxiv.org/abs/2409.17530