Heralded noiseless amplification and attenuation of non-Gaussian states of light

We examine the behavior of non-Gaussian states of light under the action of probabilistic noiseless amplification and attenuation. Surprisingly, we find that the mean-field amplitude may decrease in the process of noiseless amplification - or may increase in the process of noiseless attenuation, a counterintuitive effect that Gaussian states cannot exhibit. This striking phenomenon could be tested with experimentally accessible non-Gaussian states, such as single-photon added coherent states. We propose an experimental scheme, which is robust with respect to the major experimental imperfections, such as inefficient single-photon detection and imperfect photon addition. In particular, we argue that the observation of mean-field amplification by noiseless attenuation should be feasible with current technology.