Approximate quantum Markov chains

Understand

This book is an introduction to quantum Markov chains and explains how this concept is connected to the question of how well a lost quantum mechanical system can be recovered from a correlated subsystem.

• To achieve this goal, we strengthen the data-processing inequality such that it reveals a statement about the reconstruction of lost information.
• The main difficulty in order to understand the behavior of quantum Markov chains arises from the fact that quantum mechanical operators do not commute in general.
• As a result we start by explaining two techniques of how to deal with non-commuting matrices: the spectral pinching method and complex interpolation theory.