Holevo's bound from a general quantum fluctuation theorem
MetadataShow full item record
Type of Work5 pages
Citation of Original PublicationDvir Kafri and Sebastian Deffner, Holevo's bound from a general quantum fluctuation theorem, Phys. Rev. A 86(04) (2012), DOI:https://doi.org/10.1103/PhysRevA.86.044302
RightsThis item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author.
©2012 American Physical Society
We give a derivation of Holevo's bound using an important result from nonequilibrium statistical physics, the fluctuation theorem. To do so we develop a general formalism of quantum fluctuation theorems for two-time measurements, which explicitly accounts for the back action of quantum measurements as well as possibly nonunitary time evolution. For a specific choice of observables this fluctuation theorem yields a measurement-dependent correction to the Holevo bound, leading to a tighter inequality. We conclude by analyzing equality conditions for the improved bound.