Negative Conditional Entropy of Post-Selected States
Quantum Physics
2014-09-05 v2
Abstract
We define a quantum entropy conditioned on post-selection which has the von Neumann entropy of pure states as a special case. This conditional entropy can take negative values which is consistent with part of a quantum system containing less information than the whole which can be in a pure state. The definition is based on generalised density operators for postselected ensembles. The corresponding density operators are consistent with the quantum generalisation of classical conditional probabilities following Dirac s formalism of quasiprobability distributions.
Cite
@article{arxiv.1305.0932,
title = {Negative Conditional Entropy of Post-Selected States},
author = {Sina Salek and Roman Schubert and Karoline Wiesner},
journal= {arXiv preprint arXiv:1305.0932},
year = {2014}
}