Characterizing quantum channels via Wigner-Yanase skew information

Based on the Wigner-Yanase skew information, we introduce a new measure to characterize the difference of the global information content with respect to the local operations. The effectiveness of the measure is shown by several examples. By comparing with the decoherent information of a quantum channel, we conclude that the measure can be used as an alternative quantity in the description of capability of quantum channels, which is in term of skew information, instead of von Neumann entropy.