For the first time, a team of US researchers has used sensors containing highly excited Rydberg atoms to detect signals from an ordinary handheld radio. Through a careful approach to demodulating the incoming signals, Noah Schlossberger and colleagues at the National Institute of Standards and Technology (NIST) were able to recover audio encoded in multiple public radio channels, with promising implications for everyday uses in consumer electronics. The research has been published in Physical Review Applied.
In a Rydberg atom, a single electron is excited to an extremely high energy level, pushing it far from its host atom’s nucleus. From a distance, these atoms resemble a single electron orbiting a positively charged ion.
When any atom is exposed to an external electric field, the positions of its electrons’ energy levels shift through a process called the Stark effect. Yet in a Rydberg atom, the shift becomes far more pronounced, causing particularly striking changes in the spectral patterns produced when the atom is probed by a laser.







