Pure states and unitary dynamics suffice to handle perfectly isolated quantum systems. Measurements and interactions with an uncontrolled environment introduce irreversibility and call for a wider setting. This chapter provides the basic necessary mathematical tools like mixed states, POV-measures, and completely positive maps and semi-groups. It considers fundamental structural results such as Stinespring's theorem, Kraus decompositions, and Lindblad generators. It situates these mathematical results in a physical context and presents applications to spin systems and Fermionic systems.
Oxford Scholarship Online requires a subscription or purchase to access the full text of books within the service. Public users can however freely search the site and view the abstracts and keywords for each book and chapter.
If you think you should have access to this title, please contact your librarian.