Ultra-wideband continuous spectrum Rydberg atomic superheterodyne receiver with high sensitivity

Highly sensitive detection of microwave (MW) fields throughout ultra-wideband spectrum is always an important subject in metrology, electromagnetism and cosmology. Rydberg atomic electrometers, which implement electric field measurements by detecting the disturbance of atomic energy levels, have the potentials to breakthrough the sensitivity and size limits of conventional sensors. However, due to the discrete structure of the energy levels, current measurements can only exhibit high sensitivity at the discontinuous frequencies which correspond to certain transitions. In this work, by implementing energy level modulation of Rydberg atom through Zeeman effect, we achieve continuous highly sensitive MW fields detection within 1-40 GHz ultra-wideband spectrum where the detection sensitivity is roundly below 65 nV cm-1 Hz-1/2, which is 2-3 orders of magnitude lower than that of the state-of-the-art continuous measurement architectures. The proposed method is expected to expand the working bandwidth from MHz to THz and therefore greatly accelerate the practical applications in the areas of radar and electronic reconnaissance. Detecting microwave fields across an ultra-wideband spectrum is crucial for advancements in metrology, electromagnetism, and cosmology. Here, the authors utilize Zeeman effect modulation of Rydberg atoms to achieve continuous, highly sensitive detection from 1-40 GHz, significantly enhancing sensitivity and potentially transforming radar and electronic reconnaissance applications.