Hypercontractivity for Semigroups of Unital Qubit Channels
نویسندگان
چکیده
منابع مشابه
Additivity for Unital Qubit Channels
Additivity of the Holevo capacity is proved for product channels, under the condition that one of the channels is a unital qubit channel, with the other completely arbitrary. As a byproduct this proves that the Holevo bound is the ultimate information capacity of such qubit channels (assuming no prior entanglement between sender and receiver). Additivity of minimal entropy and multiplicativity ...
متن کاملAdditivity for a class of unital qubit channels
Additivity of the Holevo capacity is proved for product channels, under the condition that one of the channels is in a certain class of unital qubit channels, with the other completely arbitrary. This qubit class includes the depolarizing channel. As a byproduct this proves that the Holevo bound is the ultimate information capacity of such qubit channels (assuming no prior entanglement between ...
متن کاملHypercontractivity for perturbed diffusion semigroups
μ being a nonnegative measure satisfying some Log-Sobolev inequality, we give conditions on F for the Boltzmann measure ν = eμ to also satisfy some Log-Sobolev inequality. This paper improves and completes the final section in [6]. A general sufficient condition and a general necessary condition are given and examples are explicitly studied. Résumé. μ étant une mesure positive satisfaisant une ...
متن کاملA Domain of Unital Channels
The common practice of slightly rewording the first paragraph or two of the introduction and calling it an abstract has always seemed a colossal waste of space to the author. Here, we will try to be as brief and to the point as possible. In this paper we prove the space of unital qubit channels is a Scott domain. We also provide a simple protocol to achieve Holevo capacity for these channels.
متن کاملMaximal output purity and capacity for asymmetric unital qudit channels
We consider generalizations of depolarizing channels to maps of the form Φ(ρ) = ∑ k akVkρV † k + (1 − a)(Tr ρ) 1 dI with Vk unitary and ∑ k ak = a < 1. We show that one can construct unital channels of this type for which the input which achieves maximal output purity is unique. We give conditions on Vk under which multiplicativity of the maximal p-norm and additivity of the minimal output entr...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Communications in Mathematical Physics
سال: 2014
ISSN: 0010-3616,1432-0916
DOI: 10.1007/s00220-014-1982-4