Imaging of microwave fields using ultracold atoms

TL;DR

This paper introduces a non-invasive, high-resolution microwave field imaging technique using ultracold atoms as sensitive probes, capable of mapping microwave magnetic fields with micrometer precision and potential for 3D imaging.

Contribution

The authors develop a novel method employing ultracold atoms for microwave field imaging, enabling quantitative, high-resolution, and non-invasive measurements with straightforward data analysis.

Findings

Successfully imaged microwave near-field distribution around an atom chip coplanar waveguide.

Achieved micrometer spatial resolution in 2D microwave magnetic field imaging.

Demonstrated the method's potential extension to 3D imaging.

Abstract

We report a technique that uses clouds of ultracold atoms as sensitive, tunable, and non-invasive probes for microwave field imaging with micrometer spatial resolution. The microwave magnetic field components drive Rabi oscillations on atomic hyperfine transitions whose frequency can be tuned with a static magnetic field. Readout is accomplished using state-selective absorption imaging. Quantitative data extraction is simple and it is possible to reconstruct the distribution of microwave magnetic field amplitudes and phases. While we demonstrate 2d imaging, an extension to 3d imaging is straightforward. We use the method to determine the microwave near-field distribution around a coplanar waveguide integrated on an atom chip.