Floquet Engineering to Overcome No-Go Theorem of Noisy Quantum Metrology

TL;DR

This paper introduces a Floquet engineering scheme that overcomes the no-go theorem in noisy quantum metrology, enabling high-precision measurements by restoring ideal sensitivity scaling despite decoherence.

Contribution

The authors propose a novel Floquet engineering approach that forms bound states to counteract noise, restoring quantum Fisher information scaling in noisy environments.

Findings

Restores $t^2$ sensitivity scaling with Floquet bound states.

Achieves Heisenberg-limit scaling with atom number $N$.

Provides an efficient method to surpass the no-go theorem in noisy quantum metrology.

Abstract

Permitting a more precise measurement to physical quantities than the classical limit by using quantum resources, quantum metrology holds a promise in developing many revolutionary technologies. However, the noise-induced decoherence forces its superiority to disappear, which is called no-go theorem of noisy quantum metrology and constrains its application. We propose a scheme to overcome the no-go theorem by Floquet engineering. It is found that, by applying a periodic driving on the atoms of the Ramsey spectroscopy, the ultimate sensitivity to measure their frequency characterized by quantum Fisher information returns to the ideal $t^2$ scaling with the encoding time whenever a Floquet bound state is formed by the system consisting of each driven atom and its local noise. Combining with the optimal control, this mechanism also allows us to retrieve the ideal Heisenberg-limit scaling with the atom number $N$. Our result gives an efficient way to avoid the no-go theorem of noisy quantum metrology and to realize high-precision measurements.