# Using states with a large photon number variance to increase quantum Fisher information in single-mode phase estimation

## TL;DR

This paper identifies specific quantum states with large photon number variance that can enhance phase estimation precision in quantum metrology, encouraging experimental exploration of these states.

## Contribution

It introduces particular states with high photon number variance that could improve quantum Fisher information in phase estimation.

## Key findings

- Identified states with large photon number variance.
- These states can potentially improve local phase estimation.
- Encourages experimental realization of the proposed states.

## Abstract

When estimating the phase of a single mode, the quantum Fisher information for a pure probe state is proportional to the photon number variance of the probe state. In this work, we point out particular states that offer photon number distributions exhibiting a large variance, which would help to improve the local estimation precision. These theoretical examples are expected to stimulate the community to put more attention to those states that we found, and to work towards their experimental realization and usage in quantum metrology.