A one-way quantum amplifier for long-distance quantum communication

In this paper, a model for single photon amplification based on cluster-state quantum computation is proposed. A rescaling of the probability amplitudes of a deteriorated qubit in favor of the one-photon component will define the amplifier’s gain. Unlike the heralded quantum amplifiers, the probabilistic success of the whole process will not depend on the successful detection of a heralding signal. Instead, the whole procedure will rely upon a single-qubit measurement, which is simpler compared to any two-qubit interaction gate in the heralded quantum amplifiers. The proposed model can be used as a qubit protector against propagation losses in long-distance quantum communication networks.