Incomplete quantum process tomography and principle of maximal entropy
Mário Ziman · Physical Review A · 2008
Our main goal is to extend and apply the principle of maximum entropy (MaxEnt) to incomplete quantum process estimation tasks. We will define a so-called process entropy function being the von Neumann entropy of the state associated with the quantum process via Choi-Jamiolkowski isomorphism. It will be shown that an arbitrary process estimation experiment can be reformulated in a unified framework and the MaxEnt principle can be consistently exploited. We will argue that the suggested choice for the process entropy satisfies a natural list of properties and it reduces to the state MaxEnt principle if applied to preparator devices.