Researchers at the US National Institute of Standards and Technology have used a glass cell of rubidium atoms to pick up real speech transmitted by an ordinary consumer walkie-talkie. It is the first time a quantum atom sensor has been demonstrated working with off-the-shelf radio equipment.
The results were published February 10, 2026 in Physical Review Applied.
Noah Schlossberger and colleagues Christopher Holloway, Nikunjkumar Prajapati, and Tate McDonald tuned rubidium atoms into highly excited “Rydberg” states. In a Rydberg atom, a single electron is pushed so far from the nucleus that the atom becomes extremely sensitive to nearby electric fields.
When a radio wave passes through the vapor cell, it shifts the energy levels of those atoms in an effect known as the AC Stark shift. The team used a secondary reference signal and signal processing to convert those atomic shifts directly into audible sound.
To understand why that matters, consider what a conventional radio receiver actually does.
It is a chain of specialised hardware. An antenna captures the signal. A filter strips out everything on the wrong frequency. An amplifier boosts what is left. A mixer shifts it to a lower frequency that a chip can process. Each stage is a separate component, and together they take up significant space and power on a circuit board.
The NIST device replaces that entire chain with a small glass cell roughly the size of a test tube, filled with rubidium gas. Two laser beams shine into the cell and excite the atoms into Rydberg states, stretching their electron orbits so wide that incoming radio waves physically distort the atoms’ energy levels. A photodetector reads those distortions as light-level changes, and the audio signal falls straight out.
There is no antenna. There is no filter. There is no amplifier. The atoms do all of it at once.
The radio in question was a Family Radio Service walkie-talkie of the kind sold in hardware and camping stores for roughly $30. The FRS system uses the UHF band around 462 to 467 MHz. The atom sensor recovered clear, intelligible speech from its transmissions.
More striking than any single channel was what the atoms could do with all of them at once. Because Rydberg atoms respond across a very wide frequency range, the receiver detected all 22 publicly accessible FRS channels simultaneously, with at least 53 decibels of isolation between neighboring channels. That level of separation is competitive with conventional radio hardware.
“We have demonstrated the flexibility of Rydberg atom receivers: they can be used to detect actual signals from consumer electronics, not just a set of ideal frequencies,” Schlossberger said in a statement released by the journal.
Holloway, who leads NIST’s Rydberg Sensor project and began investigating the technology in 2009, has previously noted that these receivers could eventually eliminate much of the circuitry at the front end of a conventional radio. In principle, a Rydberg vapor cell performs all of those functions inside a single glass container, using quantum mechanical atomic physics instead of electronic components.
The current system is not yet ready for a product. The rubidium atoms require two lasers to pump into Rydberg states, and the effective reception range estimated from the paper’s sensitivity figures is roughly 40 metres. That falls short of what consumer devices need.
The authors note that swapping in cesium atoms, which are more sensitive than rubidium, could extend the receiver’s range. Removing the need for a secondary reference signal would simplify the hardware further.
The work is funded by NIST’s NIST-on-a-Chip program, which aims to embed quantum measurement standards directly into small, portable devices.
Sources
Schlossberger N., McDonald T., Prajapati N., Holloway C.L. “Rydberg atom reception of a handheld UHF frequency-modulated two-way radio.” Physical Review Applied 25, 024031 (2026). DOI: 10.1103/jlrg-6889
Quotes in this article are drawn from a press release issued by phys.org on February 26, 2026.