System-environmental entanglement in critical spin systems under $ZZ$-decoherence and its relation to strong and weak symmetries, by Yoshihito Kuno, Takahiro Orito, Ikuo Ichinose
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SciPost Physics Core Home Authoring Refereeing Submit a manuscript About System-environmental entanglement in critical spin systems under $ZZ$-decoherence and its relation to strong and weak symmetries Yoshihito Kuno, Takahiro Orito, Ikuo Ichinose SciPost Phys. Core 9, 014 (2026) · published 4 March 2026 doi: 10.21468/SciPostPhysCore.9.1.014 pdf BiBTeX RIS Submissions/Reports Abstract Open quantum many-body systems exhibit nontrivial behavior under decoherence. In particular, system-environmental entanglement (SEE) is one of the efficient quantities for classifying mixed states subject to decoherence. In this work, we investigate the SEE of critical spin chains under nearest-neighbor $ZZ$-decoherence. We numerically show that the SEE exhibits a specific scaling law, in particular, its system-size-independent term ("$g$-function") changes drastically its behavior in the vicinity of phase transition caused by decoherence. For the XXZ model in its gapless regime, a transition diagnosed by strong Rényi-2 correlations occurs as the strength of the decoherence increases. We determine the location of the phase transition by investigating the $g$-function that exhibits a sharp change in the critical region of the transition. Furthermore, we find that the value of the SEE is twice that of the system under single-site $Z$-decoherence, which was recently studied by conformal field theory. From the viewpoint of Rényi-2 Shannon entropy, which is closely related to the SEE at the maximal decoherence, we clarify the origin of this $g$-function behavior. × TY - JOURPB - SciPost FoundationDO - 10.21468/SciPostPhysCore.9.1.014TI - System-environmental entanglement in critical spin systems under $ZZ$-decoherence and its relation to strong and weak symmetriesPY - 2026/03/04UR - https://scipost.org/SciPostPhysCore.9.1.014JF - SciPost Physics CoreJA - SciPost Phys. CoreVL - 9IS - 1SP - 014A1 - Kuno, YoshihitoAU - Orito, TakahiroAU - Ichinose, IkuoAB - Open quantum many-body systems exhibit nontrivial behavior under decoherence. In particular, system-environmental entanglement (SEE) is one of the efficient quantities for classifying mixed states subject to decoherence. In this work, we investigate the SEE of critical spin chains under nearest-neighbor $ZZ$-decoherence. We numerically show that the SEE exhibits a specific scaling law, in particular, its system-size-independent term ("$g$-function") changes drastically its behavior in the vicinity of phase transition caused by decoherence. For the XXZ model in its gapless regime, a transition diagnosed by strong Rényi-2 correlations occurs as the strength of the decoherence increases. We determine the location of the phase transition by investigating the $g$-function that exhibits a sharp change in the critical region of the transition. Furthermore, we find that the value of the SEE is twice that of the system under single-site $Z$-decoherence, which was recently studied by conformal field theory. From the viewpoint of Rényi-2 Shannon entropy, which is closely related to the SEE at the maximal decoherence, we clarify the origin of this $g$-function behavior.ER - × @Article{10.21468/SciPostPhysCore.9.1.014, title={{System-environmental entanglement in critical spin systems under $ZZ$-decoherence and its relation to strong and weak symmetries}}, author={Yoshihito Kuno and Takahiro Orito and Ikuo Ichinose}, journal={SciPost Phys. Core}, volume={9}, pages={014}, year={2026}, publisher={SciPost}, doi={10.21468/SciPostPhysCore.9.1.014}, url={https://scipost.org/10.21468/SciPostPhysCore.9.1.014},} Ontology / Topics See full Ontology or Topics database. Open quantum systems Quantum criticality Authors / Affiliations: mappings to Contributors and Organizations See all Organizations. 1 Yoshihito Kuno, 2 Takahiro Orito, 3 Ikuo Ichinose 1 秋田大学 / Akita University 2 東京大学 / University of Tokyo [UT] 3 名古屋工業大学 / Nagoya Institute of Technology Funder for the research work leading to this publication 日本学術振興会 / Japan Society for the Promotion of Science [JSPS]