Universal decay of (conditional) mutual information in gapped pure- and mixed-state quantum matter
Authors
Jinmin Yi
Kangle Li
Chuan Liu
Zixuan Li
Liujun Zou
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.
