We report a bulk optics experiment demonstrating the possibility of restoring the entanglement distribution through noisy quantum channels by inserting a suitable unitary operation (filter) in the middle of the transmission process. We focus on two relevant classes of single-qubit channels consisting in repeated applications of rotated phase damping or rotated amplitude damping maps, both modeling the combined Hamiltonian and dissipative dynamics of the polarization state of single photons. Our results show that interposing a unitary filter between two noisy channels can significantly improve entanglement transmission. This proof-of-principle demonstration could be generalized to many other physical scenarios where entanglement-breaking communication lines may be amended by unitary filters.
@article{arxiv.1707.00161,
title = {Amending entanglement-breaking channels via intermediate unitary operations},
author = {Álvaro Cuevas and Antonella De Pasquale and Andrea Mari and Adeline Orieux and Stefano Duranti and Marcello Massaro and Andrea Di Carli and Emanuele Roccia and José Ferraz and Fabio Sciarrino and Paolo Mataloni and Vittorio Giovannetti},
journal= {arXiv preprint arXiv:1707.00161},
year = {2017}
}
Comments
5 pages, 4 figures (three of them containing two internal images) and 1 table