Discrimination of bosonic dephasing quantum channels

We study the possibility of discriminating between two bosonic dephasing quantum channels. We show that unambiguous discrimination is not realizable. We then consider discrimination with nonzero error probability and minimize this latter in the absence of input constraints. In the presence of an input energy constraint, we derive an upper bound on the error probability. Finally, we extend these results from single-shot to multi-shot discrimination, envisaging the asymptotic behavior.