Noise assisted Ramsey interferometry

TL;DR

This paper proposes a noise-assisted Ramsey interferometry method using a stationary product state to enhance frequency estimation precision by extending evolution time, without relying on entanglement.

Contribution

It introduces a strategy that leverages correlated dephasing to improve precision in Ramsey interferometry without entanglement, allowing longer evolution times.

Findings

Improved precision proportional to free evolution time.

No change in scaling with the number of atoms.

Utilizes stationary states under correlated dephasing.

Abstract

I analyze a metrological strategy for improving the precision of frequency estimation via Ramsey interferometry with strings of atoms in the presence of correlated dephasing. This strategy does not employ entangled states, but rather a product state which evolves into a stationary state under the influence of correlated dephasing. It is shown that by using this state an improvement in precision compared to standard Ramsey interferometry can be gained. This improvement is not an improvement in scaling, i.e. the estimation precision has the same scaling with the number of atoms as the standard quantum limit, but an improvement proportional to the free evolution time in the Ramsey interferometer. Since a stationary state is used, this evolution time can be substantially larger than in standard Ramsey interferometry which is limited by the coherence time of the atoms.