Rydberg atom-based field sensing enhancement using a split-ring resonator

TL;DR

This paper demonstrates that integrating a split-ring resonator with a Rydberg atom-based sensor significantly enhances electric field measurement sensitivity, achieving detection limits down to 5 μV/m, surpassing previous capabilities by two orders of magnitude.

Contribution

The study introduces a novel integration of a split-ring resonator with Rydberg atom sensors, markedly improving sensitivity and minimal detectable electric fields in the GHz range.

Findings

SRR provides 100x enhancement in E-field sensitivity.

Detection of electric fields as low as 5 mV/m with SRR.

Sensitivity of 5.5 μV/√Hz achieved using combined EIT and heterodyne detection.

Abstract

We investigate the use of a split-ring resonator (SRR) incorporated with an atomic-vapor cell to improve the sensitivity and the minimal detectable electric (E) field of Rydberg atom-based sensors. In this approach, a sub-wavelength SRR is placed around an atomic vapor-cell filled with cesium atoms for E-field measurements at 1.3~GHz. The SRR provides a factor of 100 in the enhancement of the E-field measurement sensitivity. Using electromagnetically induced transparency (EIT) with Aulter-Townes splitting, E-field measurements down to 5~mV/m are demonstrated with the SRR, while in the absence of the SRR, the minimal detectable field is 500~mV/m. We demonstrate that by combining EIT with a heterodyne Rydberg atom-based mixer approach, the SRR allows for the a sensitivity of 5.5~$\mu$V/m$\sqrt{{\rm Hz}}$, which is two-orders of magnitude improvement in sensitivity than when the SRR is not used.