1211.1098 (Chi-Hang Fred Fung et al.)

Disguising quantum channels by mixing and channel distance trade-off    [PDF]

Chi-Hang Fred Fung, H. F. Chau

We consider the reverse problem to the distinguishability of two quantum channels, which we call the disguising problem. Given two quantum channels, the goal here is to make the two channels identical by mixing with some other channels with minimal mixing probabilities. This quantifies how much one channel can disguise as the other. In addition, the possibility to trade off between the two mixing probabilities allows one channel to be more preserved (less mixed) at the expense of the other. We derive lower- and upper-bounds of the trade-off curve and apply them to a few example channels. Optimal trade-off is obtained in one example. Relation with the diamond norm is also discussed.

View original: http://arxiv.org/abs/1211.1098