The decreasing property of relative entropy and the strong superadditivity of quantum channels

Authors:
Grigori G. Amosov;Stefano Mancini
Affiliations:
Department of Higher Mathematics, Moscow Institute of Physics and Technology, Dolgoprudny, Russia;Dipartimento di Fisica, Universitá di Camerino, Camerino, Italy
Venue:
Quantum Information & Computation
Year:
2009

Citing 3
Cited 1

Elements of information theory

Elements of information theory
Remark on the additivity conjecture for a quantum depolarizing channel

Problems of Information Transmission
The capacity of the quantum depolarizing channel

IEEE Transactions on Information Theory

On estimating the output entropy of the tensor product of a phase-damping channel and an arbitrary channel

Problems of Information Transmission

Quantified Score

Hi-index	0.00

Visualization

Abstract

We argue that a fundamental (conjectured) property of memoryless quantum channels, namely the strong superadditivity, is intimately related to the decreasing property of the quantum relative entropy. Using the latter we first give, for a wide class of input states, an estimation of the output entropy for phase damping channels and some Weyl quantum channels. Then we prove, without any input restriction, the strong superadditivity for several quantum channels, including depolarizing quantum channels, quantum-classical channels and quantum erasure channels.