No-go theorem for gaussian quantum error correction.
We prove that Gaussian operations are of no use for protecting Gaussian states against Gaussian errors in quantum communication protocols. Specifically, we introduce a new quantity characterizing any single-mode Gaussian channel, called entanglement degradation, and show that it cannot decrease via Gaussian encoding and decoding operations only. The strength of this no-go theorem is illustrated with some examples of Gaussian channels.
Niset
Julien
J
Université Libre de Bruxelles, 1050 Brussels, Belgium.
Fiurásek
Jaromír
J
Cerf
Nicolas J
NJ