Cooling radio waves to their quantum ground state

Researchers at Delft University of Technology have found a new way to cool radio waves all the way down to their quantum ground state. To do so, they used circuits that employ an analog of the so-called laser cooling technique that is frequently used to cool atomic samples. The device used a recently developed technique the researchers call photon pressure coupling, which is predicted to be of use in detecting ultra-weak magnetic resonance (MRI) signals or for quantum-sensing applications that can help the search for dark matter. The results have been published in Science Advances.