Ancilla-assisted schemes are beneficial for Gaussian state phase estimation
Physical Review A 101, 012124 (2020)
We study interferometry with Gaussian states and show that an ancilla-assisted scheme outperforms the classical strategy for all levels of loss. We find the optimal measurement observable for each scheme discussed. We also find that with the appropriate measurement, the achievable precision achieved by the proposal by Caves [Phys. Rev. D 23, 1693] can be improved upon, and is less vulnerable to losses than previously thought.