Instantaneous Bandwidth Expansion of a Gradient Magnetic Field-Enhanced Rydberg Atomic Receiver

The application of magnetic fields for frequency tuning of Autler-Townes (AT) splitting in Rydberg electrometry has been experimentally demonstrated. In this article, we provide a theoretical understanding of electromagnetically induced transparency (EIT) signals with gradient magnetic fields and demonstrate some advantages of this technology compared to traditional Rydberg electrometry. Our experiments demonstrate that customized anti-Helmholtz coil configurations enable Zeeman splitting ( ${m}_{J}$ -level separation) and state dressing in Rydberg atoms, yielding broadband EIT-AT spectra. Additionally, we investigated the response bandwidth of a Rydberg atomic receiver in a superheterodyne architecture. We proposed a gradient vector magnetic field configuration that extends the system’s instantaneous bandwidth to MHz while achieving a sensitivity of $53~\text {nVcm}^{-{1}}\text {Hz}^{-\text {1/2}}$ comparable to conventional schemes. Our work is expected to expand the application of Rydberg atoms in multiple fields such as electronic information, communication, and electric field measurement.