74 citations · 374 across the 25 of their papers we have counts for
12 papers · 1 filter
Concentration of quantum channels with random Kraus operators via matrix Bernstein inequality
Motohisa Fukuda
In this study, we generate quantum channels with random Kraus operators to typically obtain almost twirling quantum channels and quantum expanders. To prove the concentration pheno…
Typical entanglement for Gaussian states
Motohisa Fukuda, Robert Koenig
We consider ensembles of bipartite states resulting from a random passive Gaussian unitary applied to a fiducial pure Gaussian state. We show that the symplectic spectra of the red…
RTNI - A symbolic integrator for Haar-random tensor networks
Motohisa Fukuda, Robert Koenig, Ion Nechita
We provide a computer algebra package called Random Tensor Network Integrator (RTNI). It allows to compute averages of tensor networks containing multiple Haar-distributed random u…
On the minimum output entropy of random orthogonal quantum channels
Motohisa Fukuda, Ion Nechita
We consider sequences of random quantum channels defined using the Stinespring formula with Haar-distributed random orthogonal matrices. For any fixed sequence of input states, we…
Additive bounds of minimum output entropies for unital channels and an exact qubit formula
Motohisa Fukuda, Gilad Gour
We investigate minimum output (Rényi) entropy of qubit channels and unital quantum channels. We obtain an exact formula for the minimum output entropy of qubit channels, and bounds…
Quantum channels with polytopic images and image additivity
Motohisa Fukuda, Ion Nechita, Michael M. Wolf
We study quantum channels with respect to their image, i.e., the image of the set of density operators under the action of the channel. We first characterize the set of quantum cha…
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…
An application of decomposable maps in proving multiplicativity of low dimensional maps
Motohisa Fukuda
In this paper we present a class of maps for which the multiplicativity of the maximal output p-norm holds when p is 2 and p is larger than or equal to 4. The class includes all po…
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…
Simplifying additivity problems using direct sum constructions
Motohisa Fukuda, Michael M. Wolf
We study the additivity problems for the classical capacity of quantum channels, the minimal output entropy and its convex closure. We show for each of them that additivity for arb…
On Weyl-covariant channels
M. Fukuda, A. S. Holevo
Formalism of discrete noncommutative Fourier transform is developed and applied to the study of Weyl-covariant channels. We then extend a result in quant-ph/0509126 concerning a bo…
Extending additivity from symmetric to asymmetric channels
Motohisa Fukuda
We prove a lemma which allows one to extend results about the additivity of the minimal output entropy from highly symmetric channels to a much larger class. A similar result holds…