No-Go Theorem for Gaussian Quantum Error Correction
Julien Niset, Jaromı́r Fiurášek, Nicolas J. Cerf · Physical Review Letters · 2009
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.