Quantum Conditional Probabilities and New Measures of Quantum Information
arXiv:2109.07447 · doi:10.1016/j.aop.2022.169192
Abstract
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.
20 pages, 1 appendix; Latest update includes is the pre-publication accepted manuscript; We have added a new section describing connections to other work, a new discussion of our results, and an expanded conclusion section