Robust quantum enhanced phase estimation in a multimode interferometer

TL;DR

This paper demonstrates that multi-mode interferometers using ultracold atoms can achieve quantum-enhanced phase estimation with robustness to particle loss, outperforming traditional two-mode schemes in precision and loss tolerance.

Contribution

It introduces multi-mode interferometry schemes with ultracold atoms that are robust to particle loss and surpass the shot noise limit of two-mode systems.

Findings

Multi-mode schemes maintain high precision despite particle loss.

Ring interferometer with fermions achieves uncertainty scaling of 1/(N√η).

Interacting bosons also reach comparable measurement precision.

Abstract

By exploiting the correlation properties of ultracold atoms in a multi-mode interferometer, we show how quantum enhanced measurement precision can be achieved with strong robustness to particle loss. While the potential for enhanced measurement precision is limited for even moderate loss in two-mode schemes, multi-mode schemes can be more robust. A ring interferometer for sensing rotational motion with non-interacting fermionic atoms can realize an uncertainty scaling of $1/(N\sqrt{\eta})$ for $N$ particles with a fraction $\eta$ remaining after loss, which undercuts the shot noise limit of two mode interferometers. A second scheme with strongly-interacting bosons achieves a comparable measurement precision and improved readout.