@article{bibcite_15356,
  author = {Kamil Korzekwa and Stanis{\l}aw Czach{\'o}rski and Zbigniew Pucha{\l}a and Karol {\.Z}yczkowski},
  title = {Distinguishing classically indistinguishable states and channels},
  abstract = {<p>We investigate an original family of quantum distinguishability problems, where the goal is to perfectly distinguish between <span style="font-size:129\%"><em>M</em></span> quantum states that become identical under a completely decohering map. Similarly, we study distinguishability of <span style="font-size:129\%"><em>M</em></span> quantum channels that cannot be distinguished when one is restricted to decohered input and output states. The studied problems arise naturally in the presence of a superselection rule, allow one to quantify the amount of information that can be encoded in phase degrees of freedom (coherences), and are related to time-energy uncertainty relation. We present a collection of results on both necessary and sufficient conditions for the existence of <span style="font-size:129\%"><em>M</em></span> perfectly distinguishable states (channels) that are classically indistinguishable.</p>
},
  year = {2019},
  journal = { Journal of Physics A: Mathematical and Theoretical},
  volume = {52},
  pages = {475303},
  url = {https://arxiv.org/abs/1812.09083},
  language = {eng},
}