Quantum network coding reducing decoherence effect

Quantum decoherence leads to environment-induced superselection of preferred states. Some information in the measurement apparatus is lost during communication. Even if the measurement apparatus is not entangled with the system of interest, the loss of information would occur. In this paper, we propose a feasible quantum network coding scheme reducing decoherence effect to transmit the mutual information between source node and target node. With the help of entanglement distribution by separable states, the quantum network coding scheme initially achieves quantum entanglement distribution of two crossing source-target pairs in a butterfly network. Furthermore, by means of transmission of correlations, the maximal mutual information resulting from local operations and classical communication will be transmitted to a distant receiver. Compared with the representative quantum network coding schemes, the proposed scheme transmits correlations rather than quantum state over the butterfly network. The upper bound to the concentrated information is also quantified. Analysis indicates that the proposed scheme can effectively defend against active attacks with fewer resource consumption and good region rate.