The mutual entropy (information) denotes an amount of information transmitted correctly from the input system to the output system through a channel.The (semi-classical) mutual entropies for classical input and quantum output were defined by several researchers.The fully quantum mutual entropy, which is called Ohya mutual entropy, for quantum input and output by using the relative entropy was defined by Ohya in 1983.In this paper, we $\mathrm{c}o$ mpare with mutual $\mathrm{e}\mathrm{n}\mathrm{t}\mathrm{r}\mathrm{o}_{\Psi}$ -type measures and show some resuls for quantum capacity.The mutual entropy (information) denotes an amount of information transmitted correctly from the input system to the output system through a channel.The (semi-classical) mutual entropies for classical input and quantum output were defined by several researchers.The fully quantum mutual entropy, which is called Ohya mutual entropy, for quantum input and output by using the relative entropy was defined by Ohya in 1983.In this paper, we $\mathrm{c}o$ mpare with mutual $\mathrm{e}\mathrm{n}\mathrm{t}\mathrm{r}\mathrm{o}_{\Psi}$ -type measures and show some resuls for quantum capacity.

数理解析研究所講究録Jul 1, 20060 citations

ON QUANTUM MUTUAL TYPE ENTROPIES AND QUANTUM CAPACITY

Noboru Watanabe

Stochastic Analysis: Classical and QuantumOct 1, 20050 citations

On General Quantum Mutual Entropy and Capacity

Noborn Watanabe

In communication processes, a channel has an activity to communicate information of input system to output system. The mutual entropy (information) denotes an amount of information transmitted correctly from the input system to the output system through a channel. The (semi‐classical) mutual entropies for classical input and quantum output were defined by several researchers. The fully quantum mutual entropy, which is called Ohya mutual entropy, for quantum input and output by using the relative entropy was defined by Ohya in 1983, and he extended it to general quantum systems by means of the relative entropy of Araki and Uhlmann. The capacity shows the ability of the information transmission of the channel, which is used as a measure for construction of channels. The fully quantum capacity is formulated by taking the supremum of Ohya mutual entropy with respect to a certain subset of the initial state space. One of the most important theorems in quantum communication theory is coding theorem. The quantum coding theorems are discussed by using the mutual entropy — type measures introduced in the studies of quantum information.In this paper, we compare with these mutual entropy‐type measures in order to obtain most suitable one for discussing the quantum coding theorem. We concretely calculate the quantum capacity for quantum channels.In communication processes, a channel has an activity to communicate information of input system to output system. The mutual entropy (information) denotes an amount of information transmitted correctly from the input system to the output system through a channel. The (semi‐classical) mutual entropies for classical input and quantum output were defined by several researchers. The fully quantum mutual entropy, which is called Ohya mutual entropy, for quantum input and output by using the relative entropy was defined by Ohya in 1983, and he extended it to general quantum systems by means of the relative entropy of Araki and Uhlmann. The capacity shows the ability of the information transmission of the channel, which is used as a measure for construction of channels. The fully quantum capacity is formulated by taking the supremum of Ohya mutual entropy with respect to a certain subset of the initial state space. One of the most important theorems in quantum communication theory is coding theorem. The quantum coding theorems are discussed by using the mutual entropy — type measures introduced in the studies of quantum information.In this paper, we compare with these mutual entropy‐type measures in order to obtain most suitable one for discussing the quantum coding theorem. We concretely calculate the quantum capacity for quantum channels.

AIP conference proceedingsJan 1, 20050 citations

\mathrm{c}o

mpare with mutual

\mathrm{e}\mathrm{n}\mathrm{t}\mathrm{r}\mathrm{o}_{\Psi}

-type measures and show some resuls for quantum capacity.