A method for atom-based closed-
loop control includes exciting atoms of a gas into one or more Rydberg states, applying one or more
signal processing functions to the one or more Rydberg states, and regulating a characteristic of the applied one or more
signal processing functions based on, at least in part, a response of the one or more Rydberg states to the one or more
signal processing functions. A
system for internal
quantum-state-space
interferometry includes an atomic
receiver, an interferometric pathway, and a
detector. The interferometer includes an
atomic vapor with first atomic states and second atomic states. The interferometric pathway from RF phases between the first and second atomic states is closed by a
quantum-state-space. The
detector is configured to detect a readout of an interferometric signal. Embodiments include atom-based automatic level control,
baseband processors, phase-locked loops,
voltage transducers, raster RF imagers and waveform analyzers.