Correlations of mixed systems in confining backgrounds

Abstract

We show that the entanglement of purification and the critical distance between the two mixed systems is a very powerful measure in probing phase structures of QCD and confining backgrounds as it can even distinguish the scale of chiral symmetry breaking versus the scale of confinement/deconfinement phase transitions. For two symmetric strips with equal and finite width and infinite length and in the background of several confining geometries, we numerically calculate the critical distance between them where the mutual information vanishes and show that this quantity can probe the very rich phase structures of these backgrounds. The geometries that we study here are AdS-soliton, Witten Sakai Sugimoto and deformed Sakai-Sugimoto, Witten-QCD, Klebanov-Strassler, Klebanov-Tseytlin, Klebanov-Witten, Maldacena-Nunez and Domain-Wall QCD model. For each background we also present the relation for the entanglement of purification. Finally, we show that the Crofton forms of these geometries also behave in a universal form where a well is being observed around the singularity point and therefore for all confining backgrounds, the Crofton form would also be capable of distinguishing the confining versus conformal backgrounds as it is also a tool in the reconstruction of various bulk geometries.