# Quantum metrology with a quantum-chaotic sensor

## TL;DR

This paper demonstrates that inducing chaos in quantum sensors enhances measurement sensitivity and noise robustness, offering a new approach that bypasses the need for complex entanglement preparation.

## Contribution

It introduces a novel method of using quantum chaos in sensors to improve precision and robustness, expanding beyond traditional integrable quantum systems.

## Key findings

- Chaotic quantum sensors outperform integrable ones in sensitivity.
- Chaos enhances robustness against noise in quantum measurements.
- Non-linear kicks induce chaos, improving magnetometry performance.

## Abstract

Quantum metrology promises high-precision measurements of classical parameters with far reaching implications for science and technology. So far, research has concentrated almost exclusively on quantum-enhancements in integrable systems, such as precessing spins or harmonic oscillators prepared in non-classical states. Here we show that large benefits can be drawn from rendering integrable quantum sensors chaotic, both in terms of achievable sensitivity as well as robustness to noise, while avoiding the challenge of preparing and protecting large-scale entanglement. We apply the method to spin-precession magnetometry and show in particular that the sensitivity of state-of-the-art magnetometers can be further enhanced by subjecting the spin-precession to non-linear kicks that renders the dynamics chaotic.