Adaptive protocols for SU(1,1) interferometers to achieve ab initio phase estimation at the Heisenberg limit
Mingchen Liu, Lijian Zhang, Haixing Miao
Abstract The precision of phase estimation with interferometers can be greatly enhanced using non-classical quantum states, and the SU(1,1) interferometer is an elegant scheme, which generates two-mode squeezed state internally and also amplifies the signal. It has been shown in Anderson et al (2017 Phys. Rev. A 95 063843) that the photon-number measurement can achieve the Heisenberg limit, but only for estimating a small phase shift. We relax the constraint on the range of phase by considering two adaptive protocols: one also uses the photon-number measurement with a specially tuned sequence of feedback phase; the other implements the yet-to-be-realized optimal measurement but without fine tuning.
arXiv:2307.14606•New Journal of Physics•Oct 1, 2023•8 citations