Broadband Heterodyne Microwave Detection using Rydberg Atoms with High Sensitivity

TL;DR

This paper introduces a highly sensitive, broadband microwave electric field sensor based on Rydberg atoms, capable of detecting fields as low as microvolts per centimeter over a 3 GHz range with a dynamic range of 90 dB.

Contribution

The work demonstrates a spectroscopic method using Autler-Townes splitting for simultaneous frequency and field strength measurement, with optimized conditions for maximum sensitivity and broad operational bandwidth.

Findings

Achieved sub-uV/cm/Hz^1/2 sensitivity

Extended bandwidth up to 3 GHz

Dynamic range of approximately 90 dB

Abstract

We present a Rydberg atom-based microwave electric field sensor that achieves extended dynamic range and enhanced sensitivity across a broad bandwidth. By characterizing the Autler-Townes (AT) splitting induced by a single-tone microwave field, we demonstrate a spectroscopic method that simultaneously extracts both the microwave frequency and electric field strength directly from the splitting pattern. We implement dual-tone heterodyne detection, achieving a minimum detectable field strength on the order of uV/cm and a sensitivity in the sub-uV/cm/Hz^1/2 regime, while extending the operational bandwidth up to 3 GHz. Through systematic characterization of frequency and power dependencies, we identify optimal operating conditions to minimize power broadening in the resonant AT regime and maximize sensitivity in the far-off-resonance AC Stark regime. The resulting platform combines high sensitivity, broad bandwidth, and a dynamic range of approximately 90 dB, establishing Rydberg atoms as practical sensors for precision electric field metrology.