Vanishing quantum discord is not necessary for completely positive maps

Aharon Brodutch, Animesh Datta, Kavan Modi, Angel Rivas, Cesar A Rodriguez-Rosario

Research output: Contribution to journalArticleResearchpeer-review

53 Citations (Scopus)


The description of the dynamics of a system that may be correlated with its environment is only meaningful within the context of a specific framework. Different frameworks rely upon different assumptions about the initial system-environment state. We reexamine the connections between complete positivity and quantum discord within two different sets of assumptions about the relevant family of initial states. We present an example of a system-environment state with nonvanishing quantum discord that leads to a completely positive map. This invalidates an earlier claim about the necessity of vanishing quantum discord for completely positive maps. In our final remarks, we discuss the physical validity of each approach.
Original languageEnglish
Article number042301
Number of pages5
JournalPhysical Review A
Issue number4
Publication statusPublished - 2013
Externally publishedYes

Cite this