3 papers
quant-ph2025
Indefinite causal order strategy does not improve the estimation of group action
Masahito Hayashi
We consider estimation of unknown unitary operation when the set of possible unitary operations is given by a projective unitary representation of a compact group. We show that nei…
quant-ph2025
General detectability measure
Masahito Hayashi
Distinguishing resource states from resource-free states is a fundamental task in quantum information. We have approached the state detection problem through a hypothesis testing f…
quant-ph2024
Alexander S. Holevo's Researches in Quantum Information Theory in 20th Century
Masahito Hayashi
This paper reviews Holevo's contributions to quantum information theory during the 20 century. At that time, he mainly studied three topics, classical-quantum channel coding, quant…