Benchmarking the state comparison amplifier

The state comparison amplifier is a recently proposed probabilistic quantum amplifier, intended especially for amplifying coherent states. Its realization is simple and uses only linear optics and photodetectors, and the preparation of a "guess" state, typically a coherent state. Fidelity and success probability can be high compared with other probabilistic amplifiers. State comparison amplification does, however, extract information about the amplified state, which means that it is especially important to benchmark it against a simple measure-and-resend procedure. We compare state comparison quantum amplifiers to measure-and-resend strategies, and identify parameter regimes and scenarios where these can and where they cannot provide an advantage.