Robust Quantum Control via Multipath Interference for Thousandfold Phase Amplification in a Resonant Atom Interferometer

TL;DR

This paper presents a quantum optimal control technique that leverages multipath interference to significantly enhance the robustness and phase amplification of atom interferometers, improving their sensitivity for quantum sensing applications.

Contribution

The authors develop a novel control method that exploits multipath interference to achieve thousandfold phase amplification in resonant atom interferometers, surpassing previous limitations.

Findings

Achieved thousandfold phase amplification in a resonant atom interferometer.

Demonstrated fiftyfold improvement over non-optimized performance.

Developed strategies to mitigate spurious interference from spontaneous emission.

Abstract

We introduce a novel technique for enhancing the robustness of light-pulse atom interferometers against the pulse infidelities that typically limit their sensitivities. The technique uses quantum optimal control to favorably harness the multipath interference of the stray trajectories produced by imperfect atom-optics operations. We apply this method to a resonant atom interferometer and achieve thousand-fold phase amplification, representing a fifty-fold improvement over the performance observed without optimized control. Moreover, we find that spurious interference can arise from the interplay of spontaneous emission and many-pulse sequences and demonstrate optimization strategies to mitigate this effect. Given the ubiquity of spontaneous emission in quantum systems, these results may be valuable for improving the performance of a diverse array of quantum sensors. We anticipate our findings will significantly benefit the performance of matter-wave interferometers for a variety of applications, including dark matter, dark energy, and gravitational wave detection.