Phase estimation via coherent and photon-catalyzed squeezed vacuum states

TL;DR

This paper proposes a scheme using photon-catalyzed squeezed vacuum states in a Mach-Zender interferometer to improve phase measurement accuracy, surpassing standard quantum and Heisenberg limits, with considerations of practical photon loss effects.

Contribution

It introduces a novel input state combining coherent and photon-catalyzed squeezed vacuum states to enhance phase sensitivity and quantum Fisher information beyond traditional limits.

Findings

Photon catalysis improves phase sensitivity and quantum Fisher information.

External dissipation impacts phase sensitivity more than internal dissipation.

Phase measurement can surpass the standard quantum limit and even the Heisenberg limit.

Abstract

The research focused on enhancing the measurement accuracy through the use of non-Gaussian states has garnered increasing attention. In this study, we propose a scheme to input the coherent state mixed with photon-catalyzed squeezed vacuum state into the Mach-Zender interferometer to enhance phase measurement accuracy. The findings demonstrate that photon catalysis, particularly multi-photon catalysis, can effectively improve the phase sensitivity of parity detection and the quantum Fisher information. Moreover, the situation of photon losses in practical measurement was studied. The results indicate that external dissipation has a greater influence on phase sensitivity than the internal dissipation. Compared to input coherent state mixed with squeezed vacuum state, the utilization of coherent state mixed photon-catalyzed squeezed vacuum state, particularly the mixed multi-photon catalyzed squeezed vacuum state as input, can enhance the phase sensitivity and quantum Fisher information. Furthermore, the phase measurement accuracy can exceed the standard quantum limit, and even surpass the Heisenberg limit. This research is expected to significantly contribute to quantum precision measurement.