Universal decay of (conditional) mutual information in gapped pure- and mixed-state quantum matter

Jinmin Yi, Kangle Li, Chuan Liu, Zixuan Li, Liujun Zou (Oct 28 2025).

Abstract: For spin and fermionic systems in any spatial dimension, we establish that the superpolynomial decay behavior of mutual information and conditional mutual information is a universal property of gapped pure- and mixed-state phases, i.e., all systems in such a phase possess this property if one system in this phase possesses this property. We further demonstrate that the (conditional) mutual information indeed decays superpolynomially in a large class of phases, including chiral phases. As a byproduct, we sharpen the notion of mixed-state phases.

Arxiv: https://arxiv.org/abs/2510.22867