Holevo's bound from a general quantum fluctuation theorem

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Citation of Original Publication

Dvir 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


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©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.