# Deterministic phase measurements exhibiting super-sensitivity and super-resolution

## TL;DR

This paper demonstrates a deterministic method using Gaussian states and homodyne detection to achieve both super-sensitivity and super-resolution in phase measurements, surpassing quantum noise limits with a simple setup.

## Contribution

It introduces a fully deterministic approach combining Gaussian states and homodyne measurement for simultaneous super-sensitivity and super-resolution in phase estimation.

## Key findings

- 22-fold improvement in phase resolution
- 1.7-fold enhancement in sensitivity
- Deterministic implementation with Gaussian states

## Abstract

Phase super-sensitivity is obtained when the sensitivity in a phase measurement goes beyond the quantum shot noise limit, whereas super-resolution is obtained when the interference fringes in an interferometer are narrower than half the input wavelength. Here we show experimentally that these two features can be simultaneously achieved using a relatively simple setup based on Gaussian states and homodyne measurement. Using 430 photons shared between a coherent- and a squeezed vacuum state, we demonstrate a 22-fold improvement in the phase resolution while we observe a 1.7-fold improvement in the sensitivity. In contrast to previous demonstrations of super-resolution and super-sensitivity, this approach is fully deterministic.