DC and power-frequency electric field measurement with Rydberg-atom interferometry

We propose a Rydberg-atom interferometry-based technique for direct current (DC) electric field measurement, enabling the detection of weak fields (<0.5V/cm) and unambiguous discrimination of DC electric field direction (for the one-dimensional case, i.e., ±ɛdc). This makes up for the shortcomings of measurements based on the Stark effect, which suffer from quadratic field dependence (limiting sensitivity in weak field regimes), rendering it incapable of distinguishing the DC electric field direction. Furthermore, this method extends naturally to power-frequency (PF) electric field measurement by exploiting the quasi-static approximation—valid given the PF field's characteristic timescale (∼10−2 s) vastly exceeds the interferometric measurement duration (10−6−10−3 s). Crucially, our protocol provides instantaneous PF electric field reconstruction, providing comprehensive information, including amplitude, frequency, and phase. These advancements have direct implications for traceable DC electric field measurement and noninvasive characterization of PF electric fields near high-voltage infrastructure.