MHz to sub-kHz field detection with an all-dielectric potassium Rydberg-atom sensor

TL;DR

This paper demonstrates a significant improvement in low-frequency field detection using a potassium Rydberg-atom sensor, extending the measurable frequency range down to 500 Hz with an all-dielectric setup.

Contribution

The study introduces a simple substitution of potassium for rubidium in Rydberg sensors, dramatically enhancing low-frequency field transmission and detection capabilities.

Findings

Detects fields down to 500 Hz

Extends low-frequency cutoff by nearly four orders of magnitude

Simplifies low-frequency sensing with all-dielectric design

Abstract

Rydberg sensors have significant promise as an alternative to the antenna systems used for sub-MHz frequency communications, where the scale of high-efficiency antennas is often impractically large, forcing the use of low-efficiency, electrically small antennas. The exploration of Rydberg sensors at these frequencies has been hampered by the low field transmission of the silicate vapor cells. We dramatically improve the low-frequency field transmission of silicate vapor cells by using potassium as the active medium instead of rubidium or cesium. The potassium Rydberg sensor can measure fields with frequencies down to 500 Hz in an all-dielectric sensor, effectively extending the low-frequency cutoff of the sensor by nearly four orders of magnitude compared to an equivalent rubidium vapor cell. With this simple substitution, experimentation with low-frequency sensing becomes dramatically more accessible to the community.