Advantage of Non-Gaussian Operations in Phase Estimation via Mach-Zehnder Interferometer

This study investigates the benefits of probabilistic non-Gaussian operations in phase estimation using difference-intensity and parity detection-based Mach-Zehnder interferometers (MZI). An experimentally implementable model is considered to perform three different non-Gaussian operations, namely photon subtraction (PS), photon addition (PA), and photon catalysis (PC) on a single-mode squeezed vacuum (SSV) state. The findings reveal that all non-Gaussian operations except one PC operation provide an advantage in either of the measurement schemes. This result is further supported by the analysis of the quantum Cram & eacute;r-Rao bound. When accounting for the success probability of non-Gaussian operations, two-PC and four-PA emerges as the most optimal operations in difference-intensity and parity detection-based MZI, respectively. Additionally, the corresponding squeezing and transmissivity parameters that yields the best performance are identified, making the study relevant for experimentalists. Furthermore, a general expression for the moment-generating function is derived, which is useful in exploring other detection schemes such as homodyne detection and quadratic homodyne detection.