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 powerful measure in probing the phase structures of QCD and confining backgrounds, as it can 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, Nunez–Legramandi metric, 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 IR wall, 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.

Entanglement wedge cross-section for noncommutative Yang-Mills theory

“…On the other hand, the holographic counterpart of entanglement of purification (EoP), known as the minimal cross section of the entanglement wedge (EWCS), can be computed by using the E P = E W duality [9,10,50,51]. Some recent work in this direction can be found [52][53][54][55][56][57][58][59][60][61][62]. Similar to the set up realized for the computation of HMI, here we also consider two strip-like subsystems on the boundary ∂M (∂M is the boundary of the canonical time-slice M that has been considered in the gravity dual).…”

“…On the other hand, for two disjoint interval we can obtain entanglement negativity by using eqs. (61,36). The expression of entanglement negativity suggests that we need the following results of holographic entanglement…”