The role of auxiliary photons in state discrimination with linear optical devices
Angelo C. M. Carollo, G. Massimo Palma · Journal of Modern Optics · 2002
The role of auxiliary photons in the problem of identifying a state secretly chosen from a given set of L-photon states is analysed. It is shown that auxiliary photons do not increase the ability to discriminate such states by means of a global measurement using only optical linear elements, conditional transformation and auxiliary photons.