22 citations · 41 across the 10 of their papers we have counts for
17 papers
Asymptotic performance of optimal state estimation in quantum two level system
Masahito Hayashi, Keiji Matsumoto
We derived an asymptotic bound the accuracy of the estimation when we use the quantum correlation in the measuring apparatus. It is also proved that this bound can be achieved in a…
Qubit Channels Which Require Four Inputs to Achieve Capacity: Implications for Additivity Conjectures
Masahito Hayashi, Hiroshi Imai, Keiji Matsumoto +2
An example is given of a qubit quantum channel which requires four inputs to maximize the Holevo capacity. The example is one of a family of channels which are related to 3-state c…
Existence of incomparable pure bipartite states in infinite dimensional systems
Masaki Owari, Keiji Matsumoto, Mio Murao
Based on set theoretic ordering properties, a general formulation for constructing a pair of convertibility monotones, which are generalizations of distillable entanglement and ent…
Statistical Model with Measurement Degree of Freedom and Quantum Physics
Masahito Hayashi, Keiji Matsumoto
This is an English translation of the manuscript which appeared in Surikaiseki Kenkyusho Kokyuroku No. 1055 (1998). The asymptotic efficiency of statistical estimate of unknown qua…
Disturbance of operation in quantum estimation for the Gaussian P-function
Yoshiyuki Tsuda, Keiji Matsumoto, Masahito Hayashi
For the quantum Gaussian state family, Hayashi proposed a quantum mechanical operation using beam splitters to estimate the location and scale parameters of the P-function, and he…
Simulating the Effects of Quantum Error-correction Schemes
Jumpei Niwa, Keiji Matsumoto, Hiroshi Imai
It is important to protect quantum information against decoherence and operational errors, and quantum error-correcting (QEC) codes are the keys to solving this problem. Of course,…