Efficient noiseless linear amplification protocol for single-photon state using imperfect auxiliary photon source

Noiseless linear amplification (NLA) is a crucial method to solve the photon transmission loss problem. However, most NLA protocols require an ideal auxiliary single-photon source, which is unavailable under current experimental condition. Meanwhile, their heralded amplification performance is relatively low. For enhancing the feasibility and amplification performance of the NLA, in this paper, we propose an efficient NLA protocol with a practical imperfect auxiliary single-photon source. We introduce the local-quadrature squeezing operation into the NLA protocol, which can effectively increase its amplification factor. This NLA protocol only uses some common linear-optical elements, the practical imperfect auxiliary single-photon source, and imperfect single-photon detectors, so that it is easy to implement under the existing experimental condition. It may have important applications in the future quantum information processing field.