Quantum conditional probabilities and new measures of quantum information

We use a novel form of quantum conditional probability to define new measures of quantum information in a dynamical context. We explore relationships between our new quantities and standard measures of quantum information, such as von Neumann entropy. These quantities allow us to find new proofs of some standard results in quantum information theory, such as the concavity of von Neumann entropy and Holevo's theorem. The existence of an underlying probability distribution helps shed light on the conceptual underpinnings of these results.(c) 2022 Elsevier Inc. All rights reserved.

Automated summary

We introduce a new form of quantum conditional probability to establish new measures of quantum information in a dynamic setting. We investigate the interconnections between our novel measures and conventional measures like von Neumann entropy. These measures serve as a basis for new proofs of established results in quantum information theory.