Phase magnification by two-axis countertwisting for detection noise robust interferometry

TL;DR

This paper proposes a two-axis counter-twisting echo protocol for atom interferometry that enhances sensitivity and robustness against detection noise, maintaining Heisenberg scaling with large particle numbers.

Contribution

It introduces a novel two-axis counter-twisting echo scheme that outperforms one-axis schemes in noise robustness and scalability for quantum-enhanced interferometry.

Findings

The scheme maintains Heisenberg scaling at large particle numbers.

It is robust to detection noise.

Implementation with spinor Bose-Einstein condensates is feasible.

Abstract

Entanglement-enhanced atom interferometry has the potential of surpassing the standard quantum limit and eventually reaching the ultimate Heisenberg bound. The experimental progress is, however, hindered by various technical noise sources, including the noise in the detection of the output quantum state. The influence of detection noise can be largely overcome by exploiting echo schemes, where the entanglement-generating interaction is repeated after the interferometer sequence. Here, we propose an echo protocol that uses two-axis counter-twisting as the main nonlinear interaction. We demonstrate that the scheme is robust to detection noise and its performance is superior compared to the already demonstrated one-axis twisting echo scheme. In particular, the sensitivity maintains the Heisenberg scaling in the limit of a large particle number. Finally, we show that the protocol can be implemented with spinor Bose-Einstein condensates. Our results thus outline a realistic approach to mitigate the detection noise in quantum-enhanced interferometry.