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New quantum sensors that are virtually undetectable will give Soldiers a disruptive advantage. Thanks to a new technology, a quantum sensor would give Soldiers a way to detect communication signals over the entire radio frequency spectrum, from 0 to 100 GHz.

Such wide spectral coverage by a single antenna is impossible with a traditional receiver system, and would require multiple systems of individual antennas, amplifiers and other components.

David Meyer, a scientist at the U.S. Army Combat Capabilities Development Command’s Army Research Laboratory said US Army scientists were the first in the world to create a quantum receiver in 2018. The receiver uses highly excited, super-sensitive atoms—known as Rydberg atoms—to detect communications signals. 

The researchers calculated the rate of data transmission, based on fundamental principles, and then achieved that performance experimentally in their lab—improving on other groups’ results by orders of magnitude.

“Rydberg-atom based sensors have only recently been considered for general electric field sensing applications, including as a communications receiver. While Rydberg atoms are known to be broadly sensitive, a quantitative description of the sensitivity over the entire operational range has never been done.”

According to phys.org, Army scientists conducted an analysis of the Rydberg sensor’s sensitivity to oscillating electric fields over an enormous range of frequencies—from 0 to 1012 Hertz. The results show that the Rydberg sensor can reliably detect signals over the entire spectrum and compare favorably with other established electric field sensor technologies.

“Quantum mechanics allows us to know the sensor calibration and ultimate performance to a very high degree, and it’s identical for every sensor,” Meyer said. “This result is an important step in determining how this system could be used in the field.”

In the future, Army scientists will investigate methods to continue to improve the sensitivity to detect even weaker signals and expand detection protocols for more complicated waveforms.