English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

We examine the quantum correlations of spin pairs in the cyclic $XX$ spin 1/2chain in a transverse field, through the analysis of the quantum discord, thegeometric discord and the information deficit. It is shown that while thesequantities provide the same qualitative information, being non-zero for alltemperatures and separations and exhibiting the same type of asymptoticbehavior for large temperatures or separations, important differences arise inthe minimizing local measurement that defines them. Whereas the quantum discordprefers a spin measurement perpendicular to the transverse field, the geometricdiscord and information deficit exhibit a perpendicular to parallel transitionas the field increases, which subsists at all temperatures and for allseparations. Moreover, it is shown that such transition signals the change froma Bell state to an aligned separable state of the dominant eigenstate of thereduced density matrix of the pair. Full exact results for both thethermodynamic limit and the finite chain are provided, through theJordan-Wigner fermionization.

Discord and information deficit in the XX chain