Rydberg atomic receiver holds distinctive advantages of ultra-wide operating bandwidth and inherently high sensitivity in electric field measurement1, in particular, it promises unique superiority of miniaturization for low-frequency especially kHz-band signals, which hold pivotal value in applications such as long-range navigation, ground-penetrating radar, and underwater communication. However, the capability of kHz atomic receivers remains severely constrained by the shielding effects of adsorbed alkali metal atoms. Here, we propose a conceptually new self-dressing kHz signal measurement paradigm by converting the undesired coupling-laser-induced DC field to an atomic dressing, and deftly building atomic superheterodyne inside the sapphire vapor cell, which is prepared to adequately suppress the low-frequency shielding through resistivity manipulation engineering. Further, we realize strengthened interaction between the atoms and kHz field by localized enhancement of the incident signals, and finally achieve an ultrahigh sensitivity of 13.5 nV/cm/Hz1/2 at 100 kHz. This architecture represents a significant advance, with the potential to greatly accelerate the practical applications of Rydberg atomic receivers in kHz-band detection, communication, and related fields.
