The Experts below are selected from a list of 10107 Experts worldwide ranked by ideXlab platform
John A Cortese - One of the best experts on this subject based on the ideXlab platform.
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holevo Schumacher westmoreland channel capacity for a class of qudit unital channels
Physical Review A, 2004Co-Authors: John A CorteseAbstract:Using the unique nature of the average output state of an optimal signalling ensemble, we prove that for a special class of qudit unital channels, the Holevo-Schumacher-Westmoreland channel capacity is C=log{sub 2}(d)-min{sub {rho}}S(E({rho})), where d is the dimension of the qudit. The result is extended to products of the same class of unital qudit channels. Thus, the connection between the minimum von Neumann entropy at the channel output and the transmission rate for classical information over quantum channels extends beyond the qubit domain.
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relative entropy and single qubit holevo Schumacher westmoreland channel capacity
arXiv: Quantum Physics, 2002Co-Authors: John A CorteseAbstract:The relative entropy description of Holevo-Schumacher-Westmoreland (HSW) classical channel capacity is applied to single qubit channels. A simple formula for the relative entropy of qubit density matrices in the Bloch sphere representation is derived. This formula is combined with the King-Ruskai-Szarek-Werner qubit channel ellipsoid picture to analyze several unital and non-unital qubit channels in detail. An alternate proof that the optimal HSW signalling states for single qubit unital channels are those states with the minimum channel output entropy is presented. The derivation is based on the symmetries of the qubit relative entropy formula and the King-Ruskai-Szarek-Werner qubit channel ellipsoid picture. A proof is given that the average output density matrix of any set of optimal HSW signalling states for a (qubit or non-qubit) quantum channel is unique.
Vlatko Vedral - One of the best experts on this subject based on the ideXlab platform.
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quantum processes systems and information by benjamin Schumacher and michael westmoreland scope review level undergraduate and postgraduate
Contemporary Physics, 2011Co-Authors: Vlatko VedralAbstract:Quantum Processes, Systems, and Information, by Benjamin Schumacher and Michael Westmoreland, Cambridge, Cambridge University Press, 2010, 482 pp., £40.00 (hardback), ISBN 978-0-521-87534-9. Scope:...
Renato Renner - One of the best experts on this subject based on the ideXlab platform.
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one shot classical quantum capacity and hypothesis testing
Physical Review Letters, 2012Co-Authors: Ligong Wang, Renato RennerAbstract:The one-shot classical capacity of a quantum channel quantifies the amount of classical information that can be transmitted through a single use of the channel such that the error probability is below a certain threshold. In this work, we show that this capacity is well approximated by a relative-entropy-type measure defined via hypothesis testing. Combined with a quantum version of Stein's lemma, our results give a conceptually simple proof of the well-known Holevo-Schumacher-Westmoreland theorem for the capacity of memoryless channels. More generally, we obtain tight capacity formulas for arbitrary (not necessarily memoryless) channels.
H Nagaoka - One of the best experts on this subject based on the ideXlab platform.
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a general formula for the classical capacity of a general quantum channel
International Symposium on Information Theory, 2002Co-Authors: Masahito Hayashi, H NagaokaAbstract:We derive a general formula of the channel capacity for any (classical-) quantum channel. It can be regarded as a quantum version of Verdu and Han's result (see IEEE Trans. Inform. Theory, vol.40, p.1147-57, 1994). Our results contain Holevo's (see IEEE Trans. Inform. Theory, vol.44, p.269-73, 1998) and Schumacher and Westmoreland's (see Phys. Rev. A, vol.56, p.131-8, 1997) results as the stationary and memoryless case.
A S Holevo - One of the best experts on this subject based on the ideXlab platform.
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the capacity of the quantum channel with general signal states
IEEE Transactions on Information Theory, 1998Co-Authors: A S HolevoAbstract:It is shown that the capacity of a classical-quantum channel with arbitrary (possibly mixed) states equals the maximum of the entropy bound with respect to all a priori distributions. This completes the recent result of Hausladen, Jozsa, Schumacher, Westmoreland, and Wootters (1996), who proved the equality for the pure state channel.
