205 citations · 618 across the 31 of their papers we have counts for
22 papers · 1 filter
Potential output purity of completely positive maps
Christopher King
The notion of potential output purity of a completely positive map is introduced as a generalization of the regularized output purity. An upper bound is derived for this quantity,…
Multiplicativity of superoperator norms for some entanglement breaking channels
Christopher King
It is known that the minimal output entropy is additive for any product of entanglement breaking (EB) channels. The same is true for the Renyi entropy, where additivity is equivale…
Hypercontractivity for semigroups of unital qubit channels
Christopher King
Hypercontractivity is proved for products of qubit channels that belong to self-adjoint semigroups. The hypercontractive bound gives necessary and sufficient conditions for a produ…
Average output entropy for quantum channels
Christopher King, David K. Moser
We study the regularized average Renyi output entropy $\bar{S}_{r}^{\reg}$ of quantum channels. This quantity gives information about the average noisiness of the channel output ar…
Entanglement of random subspaces via the Hastings bound
Motohisa Fukuda, Christopher King
Recently Hastings proved the existence of random unitary channels which violate the additivity conjecture. In this paper we use Hastings' method to derive new bounds for the entang…
Comments on Hastings' Additivity Counterexamples
Motohisa Fukuda, Christopher King, David Moser
Hastings recently provided a proof of the existence of channels which violate the additivity conjecture for minimal output entropy. In this paper we present an expanded version of…